‍Background and Purpose 

Hamstring injuries account for a large percentage of injuries in team sport athletes and time missed due to injury. Risk factors include low eccentric strength and shorter biceps femoris fascicle length, which can be improved through methods such as flywheel training. The aim of this study was to compare the effects of training with a flywheel Romanian deadlift (RDL) to a traditional barbell RDL on hamstring strength in U20 Soccer Players.  

Methods 

Twenty competitive U20 male soccer players were randomly assigned to perform either flywheel or barbell RDL training twice per week for 6 weeks alongside their normal soccer training. Each session involved 4 sets of 6 working reps at either 80% of predicted 1RM (barbell group) or at the inertial load that resulted in the highest power (flywheel group). Peak force during a Nordic Hamstring exercise and 3RM with a barbell RDL were used as measures of eccentric and concentric hamstring strength, respectively.  

Results 

The flywheel training group had a significant 13% increase in eccentric hamstring strength, while the barbell group had a smaller, non-significant increase (5%; p = 0.282). Both groups had significant increases in barbell RDL 3RM (flywheel: +18%, barbell: +28%; p<0.05).  

Key Takeaways 

• Both the flywheel group and barbell groups had significant improvements in barbell 3RM strength, showing that either method can increase concentric hamstring strength. While the magnitude of change was slightly higher for the barbell group, this is probably due to the specificity between the training and test (e.g., both involved barbell RDL exercises).   

• However, only the flywheel RDL group had statistically significant improvements in eccentric hamstring strength.  

• These results showcase that flywheel RDL’s can be effective for simultaneously improving concentric and eccentric hamstring strength. Notably, eccentric strength is considered important for injury risk in team sport athletes.