We all know weight training is an important aspect of a runners life (whether we want to admit it or not) and most runners are familiar it's the terms "concentric and eccentric", these are the two ways muscles work. Concentric means you are getting strength from shortening the muscle while eccentric is strength from elongating the muscle. Even though they sound opposite, they actually work together to create movement. Most running experts emphasize eccentric control however they are both very important.
The Flywheel resistance trainer was originally intended for astronauts to prevent muscle deconditioning while in space. The trainer allows eccentric overload of the muscles while also providing concentric contraction. The difference between the trainer and a traditional bike is that it produces continued resistance through the range of motion where as. On a bike there is no resistance on the up pedal.
The subject that used the resistance trainer had better jump height and running speed compared to those that used traditional resistance training. Theresearch found that using the flywheel trainer for eccentric overloading resulted in increased muscle power and force production.
Flywheel resistance trainers may look funny but this information explains why they are on the sideline of every NFL game. If you can find a flywheel trainer, try incorporating it into your cross training and see what happens!
Maroto-Izquierdo, Sergio et. al. Skeletal muscle functional and structural adaptations after eccentric overload flywheel resistance training: a systematic review and meta-analysis. Journal of Science and Medicine in Sports. March 2017.
Kathleen Leninger, PT, DPT