Trying to Get The Fibers Faster
Animal work and human work differ. Unlike animals, the only thing in humans that gives us more fast fibers is if someone becomes paraplegic, experiences long bed rest or spaceflight. So it follows, the histology that is the anatomy of the cells and tissue, will largely be unchanged in people following training.
What can you try to do as a coach if you can't change the histology? The answer is activate and load the fast motor units (an alpha motor neuron and all the fibers it intervates) so that these motor units change their plasticity and cause growth.
We know that motor units are recruited following the size principle and the biggest motor units are the fastest and last to be recruited. We also know that loading too fast may decrease the activation of these motor units.
It behooves us to train with slow/moderate lengthening movements during strength training to allow the necessary time to recruit all of the motor units. Whether fast lengthening training improves motor unit recruitment rate has not been shown for resistive exercise.
Plyometric training improves the rate of muscle recruitment yet this is more likened to the tendon training the muscle then the muscle changing the passive stiffness of the tendon. It is very difficult to evaluate and monitor the results of plyometric workouts. Results of 'plyos' are very subjective from training session to training session.When plyometrics are included in strength workouts we are faced with a difficult problem as muscles and tendons recover at different rates.
Fortunately for coaches and athletes it turns out that strength training fast fiber is not complex, do great reps and...Get Strong.