The Science Behind High Intensity Training continued…
Recovery
Now that you understand how the muscle fibers function during exercise, we will talk about how they recover. If you followed the High Intensity Training Experiment, you noticed that I only worked out 2 times a week. This was done on purpose, as I continue the experiment on my own, I will go down to one workout a week. Why would I work out less rather than more? It can be summed up in one word – recovery.
As you recall from reading The Science Behind High Intensity – Part 1, Type I motor units use little energy when they operate and they also fatigue slowly. The slower a muscle fatigues, the faster it recovers. This makes sense because the Type I motor units use little energy, so it’s easier to replenish their energy supplies. The same can not be said of the Type II muscle fibers.
The Type II muscle fibers produce a higher force output, but in order to produce that output they need to consume lots of energy (glycogen). This especially true for the Type IIB muscle fibers. Although these units are only tapped for a short period of time, usually seconds, they need anywhere from 4-5 days of rest before they can fully recover. If they are called upon any earlier than that, they tend to fail long before the previous failure point. It is recommended that the rest period between workouts be anywhere from 7-11 days. This gives the muscles not only time to recover, but also to grow beyond their previous capacities.
According to some trainers, there is no advantage to working out more than once a week after the initial 8 weeks. And after the 12th week it can actually cause your results to regress.
