• Can drop jumps be an effective tool to identify ACL injury risk factors in females?
• Joel Hansson’s simplistic but effective approach for developing speed in youth athletes
• Shoulder injuries and swimming

Can drop jumps be an effective tool to identify ACL injury risk factors in females?

ACL tears among female athletes frequently occur during rapid landings, making drop jumps a common method for assessing ACL injury risk. However, there is ongoing debate about whether drop jumps focused on maximum vertical jump height or those emphasising a quick vertical jump are more effective in identifying risk factors for ACL injuries in female athletes.

A recent study delved into this issue by having female athletes complete three trials of both types of drop jumps while collecting kinematic and kinetic data. The findings revealed that drop jumps performed with a quick vertical jump resulted in stiffer landings, increased frontal-plane knee motion, and heightened muscle activity in the semitendinosus and vastus lateralis muscles. As a result, the researchers proposed that drop jumps, emphasising a quick vertical jump, are more effective tools than those focused on maximum height in identifying ACL risk mechanics among female athletes.

(For clarity, we used the same terminology as in the study. If you have read one of our previous editions of SFS Weekly (see here), you may remember that technically, drop jumps with a maximum vertical jump are classified as “depth jumps,” while drop jumps with a quick vertical jump are simply referred to as “drop jumps.” In summary, based on the study’s findings, drop jumps appear to be more effective indicators of ACL injury risk than depth jumps.)

Joel Hansson’s simplistic but effective approach for developing speed in youth athletes

Leading Swedish S&C coach Joel Hansson recently shared a simplistic yet highly effective viewpoint on LinkedIn regarding the development of speed in youth athletes. He emphasises that true speed training doesn’t begin with “A-skips or ladder drills,” but rather with allowing young athletes to run!

Hansson involves his youth athletes in running activities that include various directions, such as backward and lateral sprints. He also encourages them to accelerate from different starting positions and to run in various shapes and curves. While structured speed training and sprint mechanics are important, Hansson’s approach of exposing young athletes to a diverse range of running scenarios lays a strong foundation for their future development as they grow older.

If you’re interested in seeing Hansson’s post and a video showcasing his methods in action, please click here.

Shoulder injuries and swimming

A large-scale systematic review and meta-analysis revealed some troubling findings regarding shoulder injuries among swimmers. The study encompassed nearly 11,000 participants and found that more than 70% of the literature reviewed reported incidences of shoulder injuries. Notably, the second-most affected area was the knee, which appeared in 34% of the reviewed studies.

Another important finding was that the prevalence of shoulder injuries increased with higher levels of swimming performance. This research underscores the pressing need for improved strategies for preventing and managing shoulder injuries in swimmers, highlighting the vulnerability of the shoulder region in this sport.

If you would like to learn more about shoulder injuries, check out our excellent course Shoulder Injury Rehab.

From us this week:

>> New course: Hormonal and Non-Hormonal Contraceptives in Female Athletes
>> New podcast: The Evolution of Professional Cricket Through Ryan Sidebottom’s Career
>> New infographic: Beetroot Juice
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post Identifying ACL Injury Risk! appeared first on Science for Sport.

• Are hill sprints beneficial for developing acceleration?
• Mike Young’s approach to developing speed
• The injury risk in padel tennis?

Are hill sprints beneficial for developing acceleration?

Recent research has uncovered some fascinating potential benefits of incorporating hill sprints into training for team sport athletes. The research involved 22 sub-elite Gaelic football and hurling players who performed 10-meter sprints on three different surfaces: a flat surface, a 5° incline, and an 8° incline.

While it’s not surprising that uphill sprints resulted in slower times, the researchers found significant changes in kinematics. Specifically, hill sprints led to decreases in step length, step frequency, and step velocity, while increasing ground contact time. These effects became more pronounced with steeper inclines. The kinematic adjustments observed during uphill sprinting appear to optimise force production during ground contact, suggesting that this type of training can enhance acceleration by promoting greater force generation.

So, if you’re looking to improve acceleration in team sport athletes and have access to a hill nearby, incorporating hill sprints could be an effective and free option to boost their acceleration!

Mike Young’s approach to developing speed

Recently, world-renowned Mike Young shared a concise Instagram reel packed with valuable insights on sprint training. He begins by emphasising a critical point: if you’re sprinting at an intensity below 95% of your maximum, you’re not really sprinting—you’re just running fast! From there, Young argues that consistent sprint exposure is essential for protecting athletes from injuries, noting that submaximal running is less effective for boosting speed or preventing injuries compared to true sprinting.

He recommends that athletes incorporate maximal effort sprints into their regular training regimen, while carefully monitoring the overall volume. Young suggests that speed sessions should total between 200 and 250 meters of sprinting, divided into multiple reps ranging from 15 to 40 meters each. For team sport athletes, he typically allows at least a minute and a half of recovery time between sprints, while track and field athletes should get double that rest.

Young insists that without adequate recovery time, it’s not genuine speed development. So, if you aim to enhance your athletes’ speed, take Young’s advice on board: prioritise regular sprinting, aim for at least 95% maximal intensity, track volume, and ensure proper rest between efforts!

If you are interested in developing speed, check out our courses, Speed Development, Speed Training, and Exercise Classification for Speed Development.

The injury risk in padel tennis?

Padel tennis has surged in popularity in recent years, being promoted as a safe and inclusive sport suitable for all ages and fitness levels. However, a recent study has revealed that, like many other sports, padel tennis carries certain injury risks.

The study examined 234 players and discovered an injury rate of 4.03 per 1,000 hours of play. The most frequently injured areas were the lower leg, ankle, and foot, with injuries primarily occurring close to the wall or net. Notably, professional padel players were significantly more susceptible to injuries, and those lacking prior experience in other rebound sports faced a higher risk of elbow injuries.

While padel tennis can be a fun and healthy way to stay active, this study underscores the importance of incorporating strength and conditioning training to minimise injury risks, especially at the professional level.

From us this week:

>> New course: Fundamental Movements in Youth
>> New podcast: Training for the Unknown: Olympic BMX Freestyle with Brian Roy
>> New infographic: Massage Guns
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post Do Hill Sprints Improve Acceleration? appeared first on Science for Sport.

• A new drink supplement for concussion?
• Drop the tennis racket to improve speed and change of direction ability!
• New research on optimum Nordic hamstring exercise volume

A new drink supplement for concussion?

The Edinburgh rugby union team has been experimenting with a Norwegian fruit and omega-3 smoothie called EO3 (Enhanced Omega-3) to evaluate its effectiveness in managing concussions. EO3 is packed with wild-caught Atlantic fish, providing 20 grams of protein and 1,600 mg of omega-3 fatty acids, along with vitamins D and E, as well as a variety of carbohydrates and antioxidants.

A project was conducted in collaboration with Edinburgh Rugby, comparing data from the 2022/2023 season to the 2023/2024 season when players incorporated E03 into their diet. The results were promising, showing a 28% decrease in total concussions and a remarkable 54% reduction in recovery time, shortening the average return-to-play period from 28 days to just 13 days.

Omega-3s are well-known for their benefits to brain health, including reducing inflammation and supporting the repair of neuronal membranes. Vitamin D may also play a role in brain recovery, while vitamin E helps guard against oxidative stress. Thus, it’s reasonable to suggest that a combination of these elements could explain the positive outcomes associated with EO3.

However, it’s essential to note that the project is still in its preliminary phase and has not yet been published, so we should approach the findings with caution. Still, it will be fascinating to follow future developments regarding EO3 and its potential benefits in protecting against and aiding recovery from concussions.

Drop the tennis racket to improve speed and change of direction ability!

A recent study compared the effects of speed and change of direction training in youth tennis players, with and without the use of a tennis racket. Over eight weeks, participants underwent a training intervention that involved speed and change of direction training, both with and without a racket.

To assess their performance, participants completed a 10-metre linear sprint test to measure speed. Additionally, the 505 change of direction test and the Pro Agility Test were utilised to evaluate their ability to change direction. Muscle power, which plays a crucial role in both speed and direction changes, was assessed through the CMJ test and the 10/5 repeated jump test. All assessments were carried out before and after the training program.

Significant improvements were observed in both groups; however, those who trained without the racket outperformed their counterparts who trained with it. Based on these findings, it seems that training for speed and change of direction without any extra equipment, like a tennis racket, is more effective for enhancing these capabilities in youth tennis players.

New research on optimum Nordic hamstring exercise volume

Nordic hamstring exercises are well-regarded for their effectiveness in building hamstring strength, but there has been ongoing debate about the ideal volume necessary to achieve significant strength gains. A recent systematic review and meta-analysis have offered updated recommendations on the training volume for these exercises.

This research analysed 42 studies and suggests that completing between 29 to 64 repetitions of Nordic hamstring exercises each week, spread across 2 to 3 sessions, is likely to lead to notable strength improvements, provided that progressive overload is implemented.

A limitation of the research was the considerable variation in volume among the included studies, with weekly repetitions ranging from just 3 to as many as 103, making it difficult to establish a clear recommendation. Despite this limitation, a scientifically backed guideline for the volume of Nordic hamstring exercise has now been established.

From us this week:

>> New course: Fundamental Movements in Youth
>> New podcast: How the NFL Uses Sports Science to Build Better Fields
>> New infographic: Plant-based Diets for Athletes: Sources of Dietary Protein
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post A New Supplement For Concussion? appeared first on Science for Sport.

• Can short-term exposure to cryotherapy improve athletic performance and sleep quality?
• How fast should young footballers be?
• Do professional rugby players meet their recommended macronutrient guidelines?

Can short-term exposure to cryotherapy improve athletic performance and sleep quality?

A recent study yielded mixed results regarding the use of cryotherapy. The research involved twelve Division I collegiate basketball athletes and employed a crossover, counter-balanced design. Participants were randomly assigned to either a cryotherapy exposure group, which performed post-exercise cryotherapy sessions for five days, or to a control group. The cryotherapy sessions lasted for up to three minutes, with temperatures commencing at −110℃ and gradually decreasing to −196℃.

The results indicated that post-exercise cryotherapy significantly enhanced the number of pull-ups performed by participants. However, no significant improvements were observed in other performance metrics, including the bench press, sprint speed, vertical jump, and agility tests. Furthermore, cryotherapy did not have a significant effect on sleep quality, as measured by both objective and subjective assessments.

These findings suggest that short-term post-exercise cryotherapy offers minimal enhancements to athletic performance and has no observable impact on sleep quality. It is important to note that participants spent on average, only 2 minutes and 8 seconds in the cryotherapy chambers, highlighting exposure time and the study’s limited duration as significant study limitations. Nonetheless, this study contributes to the ongoing debate surrounding the effectiveness of cryotherapy as a recovery tool.

We have an excellent podcast episode featuring Emily Partridge from the Australian Institute of Sport, discussing affordable alternatives to cryotherapy: The Cheap Alternatives To Cryotherapy.

How fast should young footballers be?

STATSports, a leading provider of GPS player tracking technology, has recently published an insightful Instagram post targeting professionals who work with young footballers. This post outlines the suggested maximum speed targets for aspiring footballers aged 16 to 21.

According to STATSports, the recommended range for individuals in this age group is between 31.82 and 33.23 km/h. The post further specifies target speeds for each age as follows:

• Age 16: 31.82 km/h
• Age 17: 32.33 km/h
• Age 18: 32.76 km/h
• Age 19: 32.94 km/h
• Age 20: 33.12 km/h
• Age 21: 33.23 km/h

While it would be unwise to rely exclusively on these figures, as other factors such as playing style, position, and maturation status must also be taken into account, these targets nonetheless serve as a useful resource for coaches working with footballers in this age range. They provide a valuable benchmark for aspiring elite footballers and their coaches to assess whether their maximum speed is adequate or requires further development.

If you’re a footballer and want to become faster, check out our excellent blog Speed Training In Football (Soccer): How To Develop This Game-Changer and our course Game Speed In Soccer.

Do professional rugby players meet their recommended macronutrient guidelines?

A recent study has highlighted the persistent disparity between research-backed nutritional guidelines and their practical implementation among athletes. The study analysed the dietary habits of 34 professional rugby players from the Italian rugby club Zebre Parma over a span of three days, encompassing a training day, a competition day, and an off day.

The American College of Sports Medicine (ACSM), the International Olympic Committee (IOC), and the International Society of Sports Nutrition (ISSN) have established macronutrient guidelines for rugby players. These guidelines recommend a daily carbohydrate intake of 5.0–8.0 g/kg of body weight and a protein intake of 1.5–2.0 g/kg of body weight while advising that 20-35% of total energy should be derived from dietary fats.

Alarmingly, the findings of the study indicate that 90% of the players did not meet the recommended daily carbohydrate intake, with an average consumption of only 2.7 g/kg of body weight, falling significantly below the established guidelines across all three monitored days. Furthermore, only 50% of the participants met the protein and fat requirements consistently over the three days.

This study illustrates that even at a professional rugby club, players struggle to adhere to the recommended macronutrient guidelines, underscoring the necessity for enhanced education and improved dietary monitoring within the sport. Although the three-day monitoring period presents a limitation to the study, the findings nonetheless serve as a valuable resource for those working in rugby.

From us this week:

>> New course: Foundations of Sports Nutrition
>> New podcast: Secrets of Success: What Makes Teams Thrive?
>> New infographic: Sodium
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post New Research On Cryotherapy! appeared first on Science for Sport.

• The latest research on foot exercises and minimalist footwear
• Do tempo runs make athletes slow?
• How rugby is changing…

The latest research on foot exercises and minimalist footwear

World-renowned researcher and sports performance consultant JB Morin has been actively promoting a recent systematic review on his social media platforms, including X and Instagram. This systematic review focuses on the effects of foot core exercises and minimalist footwear on foot muscle size, foot strength, and biomechanics.

The systematic review analysed data from 28 scientific trials involving 1,399 participants. The findings indicated that both foot core exercises and wearing minimalist footwear can significantly enhance foot strength. However, the impact of these interventions on foot muscle size remains unclear.

Regarding biomechanics, the review found that foot core exercises led to positive changes during dynamic tasks like running. Additionally, wearing minimalist shoes during running helped transition runners from a rear-foot strike to a more favourable forefoot strike pattern.

When a prominent figure like JB Morin highlights research, it’s worth paying attention. This review suggests that, while further research is needed, foot core exercises and minimalist footwear can significantly improve foot strength and facilitate positive biomechanical changes in dynamic activities such as running.

We were lucky to have JB Morin as a guest on the Science for Podcast, and his episode is well worth checking out: Get Next Level Explosive Power Using One Simple Test

Do tempo runs make athletes slow?

There is often a common fear among coaches that performing submaximal workouts, such as tempo runs, may not benefit speed athletes and could potentially slow them down. However, Fred Duncan, a regular feature on SFS Weekly, recently addressed this concern in an insightful Instagram post using the example of Usain Bolt, widely regarded as the fastest athlete of all time.

In his post, Duncan explains how Bolt’s coach, Greg Mills, identified some technical and postural issues in Bolt’s mechanics, which he believed were caused by fatigue. To address this, Mills incorporated tempo runs into Bolt’s training regimen. These tempo runs not only helped Bolt increase his endurance but also provided him the opportunity to work on his mechanics and posture at a slower speed.

Duncan further emphasises that programming high-intensity speed sessions back-to-back can hinder an athlete’s ability to supercompensate and may even lead to a decrease in speed. Instead, including lower-intensity sessions like tempo runs between high-intensity speed sessions can facilitate recovery and support an athlete’s speed development.

So, if you’re aiming to improve your speed, don’t overlook the benefits of submaximal training like tempo runs. As Duncan highlights, they certainly didn’t make Bolt slower! Tempo runs can promote recovery, build resistance to fatigue, and offer valuable opportunities to refine mechanics and technical form.

How rugby is changing…

Recently, there was an intriguing discussion on BBC Sport about how rugby has changed over the past five to ten years. Former international players Sam Warburton, John Barclay, and Ugo Monye shared their experiences regarding the intensity of their training and the straightforwardness of their coaches’ feedback.

They provided some crazy examples of the demanding training they underwent, such as needing oxygen masks after intense sessions, bear crawling until their elbows and knees were bleeding, and enduring camping conditions with minimal clothing in rugged mountain terrain—experiences that resembled “army and marine” style training camps.

The trio reflected on how coaches used to be harsh and straightforward with their feedback. Team meetings where players received harsh feedback in a humiliating manner were common. Interestingly, all three former players expressed that they appreciated this direct approach because it held them accountable to themselves and their teammates. However, they acknowledged that this method does not resonate with today’s players; coaches can no longer be as direct or harsh with their feedback as they were in the past.

Furthermore, they noted that the intensity and demands of rugby have escalated in recent years. Players are now stronger, fitter, and faster than ever, leading to increased high-speed running demands and collision impacts. As a result, they emphasised the need for coaches to closely monitor their training sessions, ensuring a balance between physically preparing players for the game and keeping them fresh and injury-free. They believe that coaches who continue to train players as they did a decade ago are likely to burn them out and ultimately shorten their careers.

What are your thoughts? Has rugby improved over the years? Is the sport now so physically demanding that players require more protection, both physically and mentally, than ever before? If you are involved in rugby, this discussion is definitely worth watching, and we would love to hear your opinions! Also, our podcast episode “What Is The Future Of Rugby S&C – Ashly Jones” is well worth a listen!

From us this week:

>> New course: One to One Psychology
>> New podcast: League Two to Premier League: Football’s Greatest Underdog Story
>> New infographic: Unilateral Training
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post Minimalist Shoes: The Latest Research! appeared first on Science for Sport.

• Addressing the misconceptions about creatine
• Does bend sprinting cause asymmetries in sprinters?
• Speed Development for youth athletes

Addressing the misconceptions about creatine

Recently, the International Journal of the International Society of Sports Nutrition published a comprehensive scientific review addressing the questions and misconceptions surrounding creatine supplementation. This review serves as an excellent resource for individuals seeking to understand the scientific evidence regarding creatine use. While it is advisable to examine the full review misconceptions for a thorough exploration of the topic, several key points warrant attention.

Firstly, it is essential to clarify some health concerns associated with creatine. The research presented in the review indicates that creatine does not cause cancer, does not adversely affect blood pressure, does not have a negative impact on male fertility, and does not increase urine production. Furthermore, the claim that caffeine and creatine counteract each other has not been substantiated. However, it is noted that combining caffeine and creatine does not result in any additional performance benefits.

Regarding the optimal timing for creatine supplementation, the evidence suggests that both pre- and post-exercise supplementation are equally effective. Notably, there is emerging research indicating that creatine may potentially reduce the severity of traumatic brain injury and aid in recovery. Additionally, creatine may have beneficial effects on memory and cognitive function during periods of sleep deprivation.

If you’re interested in understanding the science behind creatine, it’s definitely worth checking out this review and Part 1 from 2021. Additionally, if you’d like to learn more about creatine, be sure to explore our excellent course: Creatine

Does bend sprinting cause asymmetries in sprinters?

A recent study published in last month’s edition of the European Journal of Sport Science presented significant findings regarding the potential lower body asymmetries in sprinters. The investigation involved eight national-level sprinters who executed a series of 60-meter sprints at maximum speed on both straight and bend lanes (lanes one and eight).

The results indicated that sprinting on the bends increases the impact load in comparison to sprinting in straight lines. Notably, the outside leg experienced a considerably greater load during bend sprints, while the inside leg did not operate at its maximum capacity. Interestingly, the radii of the bends (lane one measuring 37 meters and lane eight measuring 45.10 meters) were not found to be significantly different.

The researchers suggest that the unique biomechanical demands of bend sprinting could create imbalances that negatively impact overall performance. They propose that the suboptimal performance of the inside leg during bend sprinting may lead to lower limb asymmetry, which could also impact speed during straight sprints. As a result, they recommend targeted training interventions to strengthen the inside leg, aiming to enhance overall sprint performance and reduce the risk of injury.

If you would like to learn more about bend sprinting mechanics, definitely check out the study and our blog Limb Symmetry Index: Chasing Equal Function is also recommended.

Speed Development for youth athletes

Shea Pierre, from the YouTube channel Pierre’s Elite Performance, has garnered significant attention with his recent video focused on speed training for young athletes. In this insightful video, Pierre highlights a key issue that can impede children from achieving their speed potential: sprinting “flat-footed.” He offers a variety of exercises designed to address this concern and optimise speed development.

Pierre emphasises the importance of exercises such as “jackhammers” and “pogo hops,” which aim to enhance ankle stiffness and promote a bouncy, spring-like motion, encouraging young athletes to stay on the balls of their feet. He also provides detailed explanations of other effective exercises, including hurdle hops, triple switches, and sled pushes. Pierre firmly believes that this collection of exercises can be incredibly beneficial in helping children reach their maximum speed potential.

For youth S&C coaches looking to foster speed development in their athletes, this video is a valuable resource. Pierre also utilises his six-year-old son to demonstrate the exercises, showcasing some impressive speed for his age. Interestingly, there has been some debate about the video. Some argue that this type of structured training is too advanced for young children and that they should be engaging in more free-play activities. Let us know what you think! We would love to hear your thoughts!

From us this week:

>> New course: Talent Identification
>> New podcast: How to Maximise Athlete Performance & Recovery
>> New infographic: How Important Is Muscular Strength To Athletic Performance?
>> New article: Hydrotherapy

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

The post Addressing The Latest Creatine Misconceptions! appeared first on Science for Sport.

1. Introduction
2. What is a KBOX?
3. What does a KBOX do?
4. How does KBOX work?
5. Is KBOX worth it?
6. How do I set up KBOX?
7. Conclusion

Introduction

The kBox is a flywheel training device that is in its fifth generation of development since its inception in 2011-12. The platform-based flywheel device offers a range of exercises to be performed in the gym (e.g. squats, hinges, rows), and is portable to travel wherever necessary (e.g. pitch, home gym, or hotel). The action of the flywheel provides a training experience that is truly unlike any other, and the physical benefits of increasing strength and hypertrophy are well-researched (1). Ultimately, for individuals looking to maximise their time and results with training, the novel stimulus allowed with the kBox can be a difference maker for athletes aiming to gain an edge regarding performance enhancement and injury resilience.

What is a KBOX?

A kBox is a platform-based flywheel training device designed by Exxentric. The platform allows users to stand atop and push against in order to perform a variety of exercises (e.g. squat, hinge, calf raise, row, etc.). Users will actively push or pull (i.e. apply force) to a strap attached to a handle, bar, or belt that works against a rotating flywheel as resistance.  Essentially, the kBox is a platform-based flywheel training device designed by Exxentric that has gone through five versions of advancements in the last twelve years.

Exxentric is arguably the leader in the resurgence of flywheel training for fitness and athletic development over the last decade. Fredrik Correa and Marten Fredriksson founded their company in 2011 after identifying a need for a more practical and efficient training tool while working with youth ice hockey players (2). Over the last decade, the kBox has continued to evolve into the premiere option for a variety of exercises using flywheel technology. It has been researched as an alternative to free weight exercises and continues to surface as a worthwhile training means that matches or exceeds the gains experienced with traditional free weight training (3). Ultimately, the stimulus experienced with a flywheel provides a meaningful stimulus that may benefit the athlete, team, or individual you work with.

The use of flywheel devices in training dates back to the late 1700s (Gymnasticon, 2).  Flywheels were used in the early 1900s for exercise physiology research and gained the strongest support in the 1990s as a training means for astronauts aiming to limit muscle and bone loss during zero-gravity space travel (2). The training experience and opportunities to load various movement patterns (e.g. squat, leg extension, etc.) through the inertia and kinetic energy generated in a flywheel provided a practical option that exposes muscles to the necessary resistance (i.e. mechanical tension) to support maintaining strength and muscle mass (2). 

With the kBox, Exxentric took the approach of training astronauts in space to training athletes in the gym, on the court, or at the pitch. With a much more favourable environment, flywheel training provides substantial increases in strength and muscle mass (1).  Through Exxentric’s advancements over the years, the kBox has become a versatile, portable, and practical option for a range of athletes to at-home exercise enthusiasts.

What does a KBOX do?

The kBox creates resistance through the rotation of weighted wheels that generate inertia based on the momentum generated during the concentric (upward) action of a movement (1). What is special about the kBox and flywheel training is that the design and materials used allow for the resistance to match the effort of the user. For example, however hard the athlete works (pushes or pulls) through the concentric action, the axle will continue to rotate and recoil the strap with the same energy that was generated. Hence the term, ‘isoinertial,’ where the load is constant due to the inertia generated by the user and kinetic energy built in (1).

Based on the strategies used during the concentric and eccentric portion, there is opportunity to experience an eccentric overload either by a delayed reception of the inertia on the eccentric side (lengthening portion of the movement), or an accentuated concentric action through assistance or a stronger position.  For example, if an athlete is squatting on the kBox, and pushes with maximal effort throughout the full range of motion (especially in the top portion of the squat where it becomes more advantageous, and the user is able to generate more energy in the wheel). As the strap recoils, the athlete can move into a deeper squat position to brake and redirect the rotating flywheel.  Given the additional energy built as the athlete accelerates up, there is potential for eccentric overload to be experienced at the bottom. This ‘overload’ has been shown to help build muscle, strength, and resiliency (5).

How does KBOX work?

Resistance training typically works with external loads and gravity (e.g. barbells, dumbbells, etc.), whereas the kBox uses inertia generated in the flywheel to create resistance similar to a yoyo. The thing to recognize is that whatever energy is generated on the way up/out (as the strap uncoils) will be returned on the way down/in (as the strap recoils). Additionally, users can use larger wheels to reduce the speed of movement and increase the amount of inertia to overcome when performing various exercises.

Due to the rotating wheel, there is a cyclical action to repetitions that is unlike any other form of resistance training.  The greatest levels of tension or generated while the muscles are at their longest length, which is an aspect beneficial to increasing hypertrophy and durability for athletes aiming to do so (4).

Due to the rotating wheel, there is a cyclical action to repetitions that is unlike any other form of resistance training.  The greatest levels of tension or generated while the muscles are at their longest length, which is an aspect beneficial to increasing hypertrophy and durability for athletes aiming to do so (4).

Given the fact that the resistance is generated by the user, the ‘variable resistance’ provided aims to maximise each repetition from the start (given the effort level of the user is maximal), and tapers to match the effects of fatigue. This allows sets to be extended further than typical mass-based resistance that remains constant. Therefore, it allows athletes to accumulate more stimulatory repetitions in a set, volume in a session, and possibly better skill and performance development.

Regarding performance metrics, the kMeter (which measures flywheel rotations) provides live, rep by rep, feedback (2). Users are able to see concentric/eccentric power, range of motion, forces produced (concentric) or yielded (eccentric), eccentric overload achieved, and energy expended for each repetition (5). This insight is useful for making training decisions and tracking progress similar to velocity-based training, these metrics provide the user with a target to achieve and can help to dictate the number of reps in a set, and sets in a given session. 

Is KBOX worth it?

Given the practicality and novelty of a kBox, I would suggest considering incorporating it into your training regime. The advancements over the last decade have made it a durable and efficient system that is able to adapt to numerous exercises (e.g. squats, hinges, rows, etc.)

Likewise, for athletes with limited training space (e.g. garage gym, on field, or travelling), they can accomplish a good amount of primary complex movements with minimal equipment and adjustments.

Therefore, if the budget allows, I think a commitment and exposure to flywheel training can be a beneficial exposure to maximising the return on strength, hypertrophy, rehabilitation, and resiliency training.

Further, there are a range of kBox options available (e.g. kBox Active, kBox Lite, kBox Pro, etc.) that vary in price (2).  This allows users to find the model that best fits their needs at an affordable price.

How do I set up KBOX?

The kBox is easy to set up, has minimal moving parts, and has great support in navigating any technical issues from Exxentric (2). The advancements in materials and interaction of parts have greatly improved over the last ten years. With the most recent rollout of the fifth generation kBox, it is arguably better than ever. The set-up process is as simple as attaching the desired attachment (e.g. belt, harness, handle), adjusting the strap to the appropriate length, deciding appropriate load, and executing the movement to ensure that the box remains stable.  All in all, the kBox provides the user with a great experience that leaves them better physically but also mentally encouraged to be consistent day to day and week to week throughout training.

Conclusion

As with the investment of any training device, there is a filter of questions that a coach and athlete must go through to decide whether the return is worth the investment. Given the consistent training benefits shown in flywheel research, that is reason enough for me to consider implementing it into training for any athlete, regardless of sport or training age (6 & 7). Flywheel training with the kBox is adaptable to the individual’s ability. Not to mention, it is versatile and portable. The exercise prescription and progression is really only limited by the imagination of the individual. Lastly, the price for the quality and durability is justifiable as well. As the saying goes, ‘you get what you pay for’ and I think for the price, the cost definitely outweighs the benefits. The kBox provides unique opportunities that could be the difference maker in an individual’s ability to be stronger, faster, and more durable.

The post kBox | Flywheel training appeared first on Science for Sport.

• New Zealand blackcurrant extract and running performance
• Lifting in the weights room to get faster
• Physical demands of soccer on artificial turf

New Zealand blackcurrant extract and running performance

New Zealand blackcurrant extract is becoming a popular sports supplement. The blackcurrants in New Zealand are grown in a region with fantastic environmental factors and strong ultraviolet sunlight. It is suggested that New Zealand blackcurrants are highly nutritious and protect against environmental stressors. Interestingly, CurraNZ Blackcurrant Extract is the official New Zealand rugby team’s supplement.

An interesting study involving New Zealand blackcurrant extract was published in this month’s International Journal of Sports Nutrition and Exercise Metabolism. The study investigated the effects of New Zealand blackcurrant extract on 5-km running performance. Sixteen trained male runners with an average VO₂ max of 55.4 ml·kg⁻¹·min⁻¹ took part in the study.

Interestingly the study found that ingesting New Zealand blackcurrant extract improved 5-km running performance by an average of 38 seconds without altering physiological or metabolic responses to exercise. The amount of New Zealand blackcurrant extract ingested was 900 mg, two hours before running. While the results are promising, more evidence is needed to fully grasp the benefits of New Zealand blackcurrant extract on exercise performance.

Lifting in the weights room to get faster

If you are interested in using the weights room to get your athletes faster, this recent video from Matt Tometz is a must-watch! Tometz outlines that while sprinting and speed training is the most specific thing to do to get faster, lifting in the weights room can also help athletes get faster.

However, lifting programs must be beneficial to your athlete’s speed development. Tometz describes the dos and don’ts of lifting to get faster. This section of the video provides insight into what to program and what to avoid when increasing speed is the goal. Tometz then provides practical programming tips to get faster. These tips are expertly discussed in detail. Some of these tips include the following:

• Super-set exercises for a contrast effect
• Throw medicine balls high and fast
• Jump with light/moderate weight
• Do a variety of plyometrics
• Be intentional with rest times

Tometz is a writer for Science for Sport too and his blogs can be viewed here. Tometz has also been a regular guest on the Science for Sport podcast and his episodes listed below are well worth checking out!

• Get Million Dollar Speed Using The Latest Sport Technology
• Optimising Youth Speed Training: They’re Not Just Small Adults
• How To Use Gym-Based Training To Rocket Your Speed

Physical demands of soccer on artificial turf

Here in Ireland, artificial turf pitches have allowed many sports to be played during the winter months. Playing and training on artificial turf is more convenient and enjoyable than a waterlogged grass pitch! Interestingly, anecdotal evidence suggests some players find artificial turf more demanding than natural grass. Therefore, I was intrigued when a study comparing the physical demands of soccer on artificial turf and natural grass was published this month.

The study used 31 elite soccer players as their participants. Participants played matches on artificial turf and natural grass. Match running performance artificial turf and natural grass was collected and analysed by GPS. The results showed that playing on artificial turf was more physically demanding for defensive and midfield players than playing on natural grass.

The authors of the study suggest that soccer coaches should consider training and recovery strategies to prepare players for the more physically demanding artificial turf surfaces. The results of this study may support the anecdotal evidence from some players that artificial turf is more physically demanding. However, more research is still needed in this area.

From us this week:

>> New course: Periodization for Football
>> New podcast: How You Can Move Like An NBA Superstar With Next Level On-Court Coordination
>> New infographic: Hamstring Injuries: How Do They Happen?
>> New article: VO₂ MAX

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

Get instant access when you join today on a 7-day free trial.

I hope you enjoyed this week’s roundup of the hottest sports science news, and as always, we’ll be back next week with more to keep you at the forefront of the industry.

The post The LATEST popular sports supplement appeared first on Science for Sport.

Here are some of the biggest happenings:

• Creatine timing, does it matter?
• How fast is Erling Haaland?
• Cobra blood and bull testicle?

Creatine timing, does it matter?

Creatine is one of the most popular and extensively studied supplements. Its safety and effectiveness have been well established by research. Creatine is typically taken to enhance high-intensity exercise capacity and increase lean muscle mass.

However, the timing of creatine supplementation has been debated. A recent expert-reviewed article by Forbes Health discusses this matter. There are two viewpoints on creatine timing. The first is that creatine should be taken close to the time of training. Whereas the other viewpoint disregards any benefit associated with timing.

This article gives a comprehensive summary of the science of creatine timing and which viewpoint is preferred. If you supplement with creatine, this article is well worth checking out!

If you would like to know more about sports supplements, then check out our blog SUPPLEMENTS IN SPORT: WHAT ARE THE BENEFITS AND RISKS?

How fast is Erling Haaland?

Erling Haaland is arguably the best striker in football today. The Norwegian had an incredible record-breaking debut season for Man City in the Premier League. His record of 36 goals is the most ever recorded by a player. Haaland’s speed is a key component to his success. So just how fast is Erling Haaland?

Recently, a video of Haaland during his Borussia Dortmund days has resurfaced on social media. In this cool video, we can see Haaland showing devastating pace and reaching 35 km/h. Interestingly, his sprint distance is approximately 100 metres too!

If you are interested in learning more about this topic, check out our blog: SPEED TRAINING IN SOCCER: HOW TO DEVELOP THIS GAME-CHANGER

Cobra blood and bull testicle?

Fox Sport Australia recently did a feature on Australian boxer, Nikita Tszyu. Tszyu discusses his diet ahead of his showdown with fellow Australian boxer, Jack Brubaker. Fresh cobra blood and bull testicles are examples of food sources in his current diet.

Tszyu attributes his peculiar diet to giving “energy rushes” and a “clear mind”. While some exotic food delicacies may be high in nutritional value, there is currently very little scientific evidence to support Tszyu’s claims. In fact, there are risks of infection associated with the consumption of exotic food delicacies. Consuming raw snakes can even lead to death as the venom may be consumed.

While this bizarre diet may work for Tszyu, the jury is still out on this.

From us this week:

>> New course: The Demands of Women’s Football
>> New podcast: Improve Your Bench Press With Essential Lessons From Para-Powerlifting
>> New infographic: Age-related decline in performance on the pitch
>> New article: Basic Movement Patterns

Access to a growing library of sports science courses

SFS Academy is an all-access membership to premium sports science education.

With SFS Academy, you’ll learn from some of the best coaches around the world as they teach you how to apply the latest research and practice with your athletes.

Get instant access when you join today on a 7-day free trial.

I hope you enjoyed this week’s roundup of the hottest sports science news, and as always, we’ll be back next week with more to keep you at the forefront of the industry.

The post Creatine timing… appeared first on Science for Sport.

The world is filled with thousands of gadgets that claim to improve your speed and acceleration, but which ones actually deliver?

By Will Saville
Last updated: March 23rd, 2025
3 min read

Speed training: How technology can help

The world is filled with thousands of gadgets that claim to improve your speed and acceleration, but which ones bring you million-dollar speed, and which just cost a million dollars?
In episode 82 of the Science for Sport podcast, Matt Tometz, Sport Science Coordinator at TCBoost Performance, divulges some industry secrets, letting you in on the cutting edge technology which is making a difference at the highest levels of sport.

First things first though – why is speed the most desired and famed physical trait? It may seem intuitive that speed changes games, wins tournaments, and defines careers, but it is also a gateway into pro sports.

“A high school baseball player who trains with us has been chatting with professional scouts, and they said that they’ll consider drafting him if he can drop his 40m sprint time. Not hit more homers, not get his arm stronger for throwing the baseball – ‘drop your 40’,” Tometz said.

So now we know speed is vital in many sports. And obviously tech can play a massive role in shaving milliseconds off your sprint time, but when it comes to technology, where do you start?
“You can get [something] as simple as Kinogram from Altis. This is a series of five pictures of someone’s sprinting technique, which just uses the slo-mo function on a phone. Although that’s not specifically measuring speed, you can just use your phone to [work out] ‘has our technique improved’?” Tometz said.

What else do you need for your speed training?

The next logical step is to get your hands on some timing gates. These are typically lasers that give you the exact time you break the beam at both the start and the end of your sprint. These are the ones that beep incessantly when they’re not working – that horrible, high-pitched noise you hear in your sleep three days after testing. Yeah, those.

“We need to be measuring speed. Now there are so many different lasers out there. We’re fortunate to have fusion smart speed lasers, so that’s a little bit higher end. There’s also stuff like Freelap, Brower, everything in between,” Tometz said.

Timing gates are the bread and butter of speed tech, but if you want to take things up a notch, there’s one piece of kit Tometz can’t live without.

“If I had unlimited money, I would use 1080 Sprint, because it spits out time, velocity, force, and power. The graph plots every step over time – it is how you run. So I can specifically say, ‘Oh, it was your fourth step that the curve kind of flattened out’,” Tometz said.

Obviously, 1080 Sprint sounds fantastic and futuristic, but what on earth is it?
“So it’s a linear transducer. Which basically measures how fast the string comes out of the machine. And that’s how it measures all of those metrics. But also one of the main selling points is that you can get super specific with the resistance, down to the 10th of a kilogram,” Tometz said.

A swift Google search will show you the 1080 Sprint will set you back north of $18,000 (USD). So if you need to have next-level precision in your sprint training, you’ll have to put your hand in your pocket.

More tips and tricks for speed training

Tometz goes on to discuss how he translates all of this great data into improved training and performance – if you want to hear more, just hit the link to the podcast below.

You can download the podcast on any of the big hosting services, including Apple Podcasts and Spotify, or just use this link: https://scienceforsport.fireside.fm/82
Don’t forget to hit the subscribe button and be sure to give us a review and rating too!

[optin-monster-shortcode id=”czosk0qsqzzsryj6gwot”]

Will Saville

More content by Will

The post Speed training: How tech can help you get faster, quickly appeared first on Science for Sport.

Speed is as critical to performance as technical and tactical mastery, as well as strength and conditioning. Here’s how to develop it to blow your opponents away on the pitch.

By Will Saville
Last updated: March 23rd, 2025
4 min read

• Speed training in football is as critical to performance as technical and tactical mastery, as well as strength and conditioning.

• There are many components of speed which athletes can develop – linear, multidirectional, deceleration, acceleration, change of direction and agility, and top speed.

• In order to achieve the right adaptations for speed improvements, coaches should supplement their drills with power-based strength and conditioning exercises.

Speed training in football: Why it’s crucial

Speed is one of the most vital dimensions of sports performance. Defined as the rate at which someone moves, speed is as critical to performance as technical and tactical mastery as well as strength and conditioning.

Without effective levels of speed, athletes can struggle to compete, so it is vital coaches and athletes focus on developing this aspect of sports performance.

“There are many components of speed which athletes can work on to improve their speed – linear, multidirectional, deceleration, acceleration, change of direction and agility, and top speed,” said leading strength and conditioning coach Andy Hyde during his Science for Sport presentation titled ‘Game Speed in Football’.

Components of speed

Linear
Linear speed efforts often happen while athletes are already in motion. In football, linear runs do not often exceed 20m and “45% of goal scoring scenarios are preceded by a linear sprint,” said Hyde.

Linear speed is measured by straight-line distance over a period of time.

“Elite football players average 17m per sprint, with forwards, wingers, and fullbacks performing more linear sprints compared to centre midfielders and centre-backs,” explained Hyde.

“To get started, wall drills are a great way to ensure athletes develop the right technique. Athletes should drive their knees forward with force and extend fully at the hip.”

Once the proper technique is adopted, shuttle runs can be included to work on linear acceleration to develop overall speed.

Multidirectional
True change of direction speed in invasion sports is rare – 77% of change of direction in football games are at an angle of less than 90°. Multidirectional speed is associated with curved angled sprints.

“Athletes who are faster in acceleration usually have greater entry velocities into change of directions, which can result in slower exit velocities. Therefore, it is important for coaches to develop athletes’ eccentric strength, eccentric rate of force, deceleration tasks, and efficient technique,” said Hyde.

To develop multidirectional speed, coaches can set up sprints that involve various changes of direction – cones and poles are helpful in forcing athletes to change direction.

Deceleration
Deceleration efforts are highly intense and should be managed and progressed carefully. According to research, high-intensity decelerations occur more often than high-intensity accelerations in field sports.

“Deceleration can be a very damaging skill and can lead to injuries if performed with incorrect technique. When in-season, be very careful when training deceleration skill development since athletes are exposed to lots of those movements during games,” explained Hyde.

YouTube is a great platform to create a needs analysis for your athletes and contains a wealth of content from elite athletes who demonstrate best practice (hips behind the feet to create breaking force), said the leading strength and conditioning coach.

Top speed
In games, athletes rarely reach their top speed – research shows athletes reach on average 92% of their top speed.

“Despite not reaching top speed, athletes engage in frequent but brief exposures towards 85-95% of maximum velocity. The goal here is to ‘bulletproof’ athletes’ hamstrings,” said Hyde.

“Coaches shouldn’t focus too much time on top speed mechanics drills, instead they should incorporate drills in the context of game-specific movements in which acceleration and decelerations are common.”

Four progressions to improve speed

Each progression should last for four weeks to enable athletes to adapt to the drills, new stimuli thrown at them, and overload safely.

“Exercises and skill progressions should be the focus, not sets and reps. In order to achieve the right adaptations for improved speed, coaches should supplement their drills with power-based strength and conditioning exercises,” said Hyde.

Progression 1

• Skill – Lateral shuffle
• Drill – Lateral mirror shuffle
• Power – Skater hop & land
• Strength A1 – Cossak Squat
• Strength A2 – Single-leg Romanian deadlift
• Core – Kneeling palloff hold

Progression 2

• Skill – Lateral shuffle
• Drill – Lateral mirror shuffle against opponent
• Power – Loaded skater hop & land
• Strength A1 – Lateral lunge
• Strength A2 – Single-leg Romanian deadlift
• Core – Standing palloff hold

Progression 3

• Skill – Lateral shuffle
• Drill – Lateral mirror shuffle with shot/block (sport-specific movement)
• Power – Reactive skater hop & land
• Strength A1 – Lateral lunge drop
• Strength A2 – Single-leg Romanian deadlift
• Core – Standing palloff hold & twist

Progression 4

• Skill – 65° cut
• Drill – Bib bulldog
• Power – Lateral hop & land
• Strength A1 – Lateral lunge push
• Strength A2 – Single-leg Romanian deadlift
• Core – Kettlebell pull-through

The post Speed training in football (soccer): How to develop this game-changer appeared first on Science for Sport.

1. Introduction
2. Speed development: How it can be a game-changer
3. Why correct running mechanics are vital
4. How to assess running mechanics: The 4 Ps

Introduction

Running mechanics are crucial for improving running economy, injury prevention and maximising athletic potential. Team sport athletes don’t need to aim to be 100m sprinters, but sprinting techniques can help any athlete generate more force. The 4 P’s – Posture, Positioning, Placement, Patterning – provide a framework to categorise drills, allowing coaches to emphasise particular components of running mechanics with athletes.

We spoke to Nathan Griffith who is currently the head of academy strength & conditioning at Oxford United FC and undertaking a PhD at the University of Birmingham, understanding and evaluating the relationship between acceleration and deceleration within academy football to find out more.

Speed development: How it can be a game-changer

Running with the right technique is vital for athletes and, with the correct mechanics, they can maximise their speed and ability to perform sport-specific actions. And perhaps more so than ever before, speed is essential as the pace of play in many team sports has increased exponentially in recent years, with athletes, coaches, and teams focusing more on speed development year-on-year, leading strength and conditioning coach Nathan Griffith says.

“Speed is such an important part of team sports and so ensuring your athletes have the right running mechanics is key to ensuring they can compete at the required level of competition. The correct technique leads to improved performance and athletic development,” Nathan Griffith said.

Why correct running mechanics are vital

According to Griffith, running with the correct mechanics has the following three benefits:

• Running economy

“The right mechanics improve an athlete’s economy, which is how efficiently they run. With a high running economy, athletes are able to maintain sub-maximal velocity for longer periods of time, enabling them to work harder for longer,” explained Griffith.

• Injury prevention

Griffith continues, “Coaching the correct technique reduces the risk of injury. At high speed, incorrect technique can expose athletes to a high risk of hamstring injuries, something to be avoided. It is essential to coach ground contact and [foot] strike on the floor.”

• Maximising athletic potential

“Using the correct mechanics ensures you are optimising your athletes’ ability to deliver maximum speed. Through maximum speed, you can improve true athletic potential by allowing your athletes to produce high quality speed movements,” mentioned Griffith.

How to assess running mechanics: The 4 Ps

Before an athlete can implement the right running mechanics, it is important to understand any technical deficiencies.

“We are not training our athletes to become 100m sprinters; however, we are taking qualities out of sprinting which improves technique, thus enabling an athlete to improve their capacity of developing force,” explained Griffith.

To assess running mechanics, the leading strength and conditioning coach suggested a 4 P’s framework – posture, positioning, placement, patterning.

“The 4 P’s enable coaches to categorise drills, allowing them to emphasise particular components of running mechanics within their athletes,” he said.

Posture relates to an athlete’s body alignment and ensuring force is directed towards the desired direction.

“Poor posture will limit their potential, and under- or over-reaching will increase the risk of injury. If aligned properly, athletes can generate maximum force,” said Griffith. “To assess alignment, take a ground-to-head approach to assess your athlete’s body alignment. You should identify if their striking leg is directly underneath their hip at the point of ground contact.”

Positioning explains the angles and mobility of the body’s joints during the mechanics of running.

“All athletes have elastic potential, and the correct running mechanics maximises this elasticity. The desired flexibility and mobility to produce sprinting force can be seen in exercises like repetitive pogo jumps,” he said.

Placement is wholly related to strike and ground contact. Are athletes striking the ground with the correct foot placement?

“For effective placement, understand the angle of the shin and the dorsiflexion at the ankle joint. You want to see a positive shin angle to get the maximum output. Plyometric exercises like bounding are a great way to assess the positions your athletes get into,” suggested Griffith.

“You should also consider if your athletes are excessively bending their knees at the point of ground contact as you want to maximise the stretch-shortening cycle.”

Patterning concerns the rhythm and tempo of an athlete’s movements.

“Actions should be worked in coordination with each other. For example, your arms need to work with your legs to form a pattern that is seamless. Where possible, encourage coordination to avoid awkward movements in isolation, since awkwardnesses may cause a decline in performance as the body transitions through specific movements,” said Griffith.

The post Speed development: Why correct technique is vital for athletes appeared first on Science for Sport.