But, all the slow + all the intermediate fibers were not strong enough to lift the weight so the brain had to recruit some fast
twitch fibers so that the weight could be lifted for the first rep. Therefore, we see that simultaneous recruitment slow, intermediate, and fast twitch fibers is occurring at the very first rep.
It requires the most energy and effort to activate the largest of the fast
twitch fibers so it seems reasonable and most effective to me to train those fibers when your energy levels are the highest, enabling the heaviest weight to be lifted and training the highest number of fibers.
Not exact matches
Consider that 80 % of the muscle
fibers in the soleus are slow -
twitch and have a slow contraction velocity and low tension capacity
so it's not the brightest idea to go heavy when training them.
When you exercise with heavy weight and low reps, you are working on all of your muscle
fibers, both the quick and the slow
twitch fibers,
so use really heavy weight that you can only lift a low number of times.
Incidentally, as well as being a useful survival tool, sprinting helps improve your muscle tone, increases anabolic hormone concentrations, lower your body fat levels, improve your aerobic and anaerobic fitness and targets your type 2b fast -
twitch muscle
fibers so as well being a life skill, you'll look and feel better too.
So what does all of this fast
twitch, slow
twitch muscle
fibers have to do with improving your strength?
The Slow
Twitch and Fast
Twitch A
fibers did not possess enough strength to lift the weight by themselves,
so the strongest of
fibers, the Fast
Twitch B
fibers, were activated.
You have to do at least 10 sets of low reps to exhaust the fast
twitch fibers enough to switch,
so you're basically doing a lot of wasted sets that cut into recovery and tissue growth.
Lifting weights quickly utilizes the fast -
twitch muscle
fibers,
so if you want to build more muscle and get stronger, lifting faster is the way to go.
Unfortunately, slow
twitch muscle
fibers are limited in their potential for growth
so even if a muscle group is primarily slow
twitch, you should definitely include some lower rep training to maximize the fast
twitch fibers you've got in that muscle.
For example, on a set of squats, the trainer takes a brief rest at the top position as he psyches himself for the next rep.. While doing
so effectively reduces the fatigue level during the set, a 2013 study that was published at the 2013 Strength and Conditioning Conference in Las Vegas, revealed that it also reduced the number of fast
twitch fibers that were recruited.
One of two surefire ways to increase the recruitment of fast -
twitch muscle
fiber is fatigue,
so consider it your friend.
This system will be another way to overload your muscles, as you will be firing those muscle
fibers so fast, you are going to recruit the fast
twitch fibers and evidently you're going to cause muscle damage (a good thing).