Post-Season and the Overshoot Phenomenon


Many great athletes view the post-season as an inconvenience because they’re being told not to do the exact thing they have been hard-wired to do their whole lives. The post-season though, is an excellent opportunity to make some gains outside of the weight room.

The research behind the overshoot phenomenon says that during prolonged periods of strength training, a significant switch in fiber types, from type IIb to IIa, occurs. After a period of detraining, another fiber type switch will occur – a switch from IIa back to IIb. During this detraining period the athlete will regain and actually “overshoot” the amount of IIb fibers they had prior to training.

In a 2000 study they tested the overshoot phenomenon. Here were the results:

  • Start (sedentary group): 9.3% type IIb
  • After 3 months of training: 2.0% type IIb
  • After 3 months of detraining: 17.2% type IIb

There obviously is an aspect of cost-benefit here. The benefit being more type IIb fibers and the cost being time spent not training. If you were to take this exact approach (3 months of no training) you would be giving up 25% of your training year. If we look at the long-term quadrennial plan, combined, that’s a whole year of no training.

Keep in mind that while detraining may increase type IIb fibers, it can also take a huge toll on fitness levels. It wouldn’t be wise to use this concept midway through a season, but this can give us better insight and understanding on how to approach the post-season for speed-power athletes.


Andersen JL, Aagaard P.Myosin heavy chain IIX overshoot in human skeletal muscle.Muscle Nerve. 2000 Jul;23(7):1095-104.

John Grace

John Grace

Sport Performance Coach at Athletic Lab
John is a Sport Performance Coach at Athletic Lab. He earned his Master's degree from Ohio University in Coaching & Sport Science. John holds his CSCS, USAW-L1, and USATF-L1. He is the former Assistant Fitness Coach of the MLS Vancouver Whitecaps FC.
John Grace


Performance Coach | @ChicagoFire | I tweet about all things sport science, coaching, training, and athlete development.
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