‍Purpose: 

To examine the effect of flywheel training on performance assessments and muscle injury incidence among junior elite soccer players.   

Methods:  

33 elite Spanish soccer players were divided into a FRT group (n = 18) or control group (CON, n = 15).  Both groups were involved in their normal on-field soccer training (practices and matches).  The FRT group participated in 1 – 2 weight training sessions per week for 10 weeks with two exercises per session (flywheel squat and flywheel leg curls).   The starting volume for each exercise occurred at 3 sets of 6 reps during the first week and linearly progressed up to 6 sets of 6 reps in week 10.  Load was determined via inertial load power profile, in which they assessed which inertial load achieved the highest concentric power output for each individual across multiple loads (i.e., the optimal power load).  The severity and number of injuries per 1000 hrs of training/match load was track 10 months prior and during the investigation.  In addition, countermovement jumps, and sprint times were assessed before and after the training intervention 

Results:  

In comparison to the FRT group, the CON group showed a greater amount of match injuries per 1000 hours and also had more severe injuries (more days missed due to injury).  The FRT group also had likely – very likely positive changes (enhanced outcomes) in CMJ height, 20 m and 10 m flying sprint times in comparison to the CON group.  Finally, the FRT group had possibly to almost certainly positive changes from pre to post in total injuries per 1000 hrs, injury severity, CMJ, 10 m sprint, 20 m sprint and 10 m flying sprint.  

Key Takeaways: 

• Although the means of analysis for the injury data was limited in this investigation, the finding support the theoretical evidence that FRT can reduce injury risk and limit the severity of injuries.   

• Utilizing only 2 flywheel exercises per training session can lead to enhancements in jumping and sprinting ability.   

• Utilizing an inertial power profile assessment to individualize inertial load to an athlete’s power capabilities seems to be an effective way to program, improve performance, and prevent injuries.