‍Purpose: 

To compare the effects of flywheel resistance training (FRT) vs pneumatic resistance training (PN) on muscle structure and performance outcomes in professional handball players.

Methods: 

18 professional handball players were randomly divided into a FRT group (n = 9) or PN (n = 9).  Both groups completed 2 training sessions per week across 6 weeks.  Each training session consisted of 3 single arm movements (lateral raise, internal and external rotation).  4 sets of 7 reps for each movement (throwing arm only) were performed during each session. Inertial 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).  Similar protocol was also utilized to determine PN load.  Muscle thickness of the shoulder, isokinetic measurements, and throwing speed were assessed before and after the training interventions.  

Results: 

Both groups significantly increased their throwing speeds (standing, sitting and heavy ball throwing).  Similarly, both groups improved their internal and external rotation isokinetic measures (peak torque, average and peak power).  However, the FRT group had significantly greater muscle thickness growth (anterior and middle deltoid) in comparison to the PN group (FRT = 20% and 22%, vs PN = 14% and 7%, respectively) 

Key Takeaways: 

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

• Both FTR and PN can lead to similar gains in throwing speed, and improvements in shoulder strength and power.  However, FRT appears to drive greater hypertrophic effects.  Increases in hypertrophy can lead to a reduction in injury risk.  In addition, hypertrophy plays a pivotal role in the magnitude of muscle strength and power.