Athletes have three goals: Build muscle, get stronger and increase explosiveness.
Some athletes only want one of these things. Some want to be strong as an ox with no regard for quickness. Some want to be muscular, but are weak as a kitten. And some want to be explosive, yet have no muscle mass on their frame.
In my time as a strength coach, such "one-issue" athletes are rare. Most athletes are not specialists in their training goals, but instead generalists. They want it all: to be jacked, strong and powerful. They want explosive muscle.
Unlike the specialists who succeed in reaching their goals, the generalists don't get very far. After years of training, they don't look like they lift, they aren't squatting or benching any heavier, and they still look like they're playing sport in molasses.
Some phrases that come to mind for these athletes—"the jack of all trades, master of none" and "the man who chases two rabbits catches none."
Why do these athletes fail to reach their goals? Because gaining muscle, strength or power require different intensities:
Not only do intensities differ for development of these goals, but volume (number of reps you perform) also plays a huge role.
I've explained these facts to hundreds of athletes. Still, most are not interested in changing their training goals. They are only interested in one thing—how can they train for everything and still get awesome results?
Phase potentiation is a system of periodization where athletes spend weeks to months in each of the following sequential training phases:
Based on work by Haff et al. and DeWeese et al., training for Hypertrophy will cause strength gains since muscle mass provides the raw material for strength. More raw material (muscle) = More potential for strength.
The same happens to power when an athlete gets Stronger. More strength will increase power because power is a submaximal amount of one's maximal strength. An increase in strength will yield a potential increase in power. Greater maximal force (strength) = greater submaximal force (power).
Finally, as an athlete trains to enhance Power output, their power is increased from the prior size and strength gains. Size builds strength, and strength builds power.
I used this system for several years with a high degree of success. Athletes get bigger, stronger and faster, fulfilling all their goals. However, there was still one problem: When I took athletes through a typical Hypertrophy Phase, they gained muscle, but their vertical jumps would decrease. They got bigger, but they also got slower.
This presented a question: is there a way to gain muscle without sacrificing power?
The answer: Use intraset rest during the hypertrophy phase to preserve and increase power.
For a Squat exercise, typical hypertrophy training looks something like this:
Back Squat: 4 sets of 10 reps @ 65%, rest 2-3 minutes between sets
For gaining muscular legs, there is no issue with this. It produces decent amounts of mechanical tension and metabolic stress with high volume—all traits of successfully training to gain muscle.
However, this set/rep scheme kills power output and power development. As the set progresses to repetitions 6, 7, 8, 9, and 10, velocity sees a huge drop-off. Since Power = Force x Velocity, this decreases power to a significant degree. Over time, training with these low-power set/rep schemes will lead to decreases in power.
The simple fix is to use intraset rest. This changes typical hypertrophy training to look like this:
Back Squat: 8 sets of 5 reps @ 65%, rest 60-90 seconds between sets
Notice that you do the same number of total reps at the same intensity. But you split up the sets so you can maintain your power, and as a result slightly shortening the rest periods between sets.
A few things happen when this is done:
Athletes aren't at fault for chasing after too many goals. If you want to get jacked, build strength and increase power, find a method that enhances all those qualities. Intraset rest is a simple, effective way to get what we all want—explosive muscle.