Almost any guy that’s ever been interested in hypertrophy training has tried to find the best rep range for size. How many reps you do is imperative because it not only dictates how much weight you use, but how long the muscle is under tension, how the nervous system is affected and more. While this may seem understandable to you, what you might not expect is that there can be more than one best rep range for size.
Types of Hypertrophy
Before trying to find the best rep range for size, you have to understand that there is more than one type of “size” (i.e. – hypertrophy) you can build. Myofibrillar hypertrophy is the dense, hard muscle that’s built as a result of lifting heavier weights for moderate reps. Sarcoplasmic hypertrophy built from maximizing fluid in muscle cells is from lifting lighter weights for higher reps.
In order to maximize myofibrillar hypertrophy, the best rep range for size is going to be 6-10 reps per set. This will allow you to lift heavy enough weight to maximize muscular contraction, as well as stimulate proper nervous system response. However, because adequate total volume (i.e. – the total number of reps performed of an exercise) is necessary, you’ll want to ensure you’re doing sufficient sets, as well. Enough sets to net you 35-50 total reps for an exercise, performed at 6-10 reps per set often works well.
Probably the easiest way to think of sarcoplasmic hypertrophy is “pump sets” since the goal is to pump as much blood into the muscle as possible. As such, the best rep range for size is on the higher end: 12-15 or more. Because you want to go for a maximum muscle pump, bump up the total reps performed to something like 60-75 or more per exercise. This would mean that while you’re doing 12-15 reps or more per set, you’ll still want to do several sets.
Compound vs Isolation Movements
One other idea that begs mentioning in this discussion is not what best rep range for size is, but what types of exercises it’s applied to. For instance, you might be able to do heavy(-ish) sets of 8-10 on an isolation movement such as lateral raises, and still get a good workout. However, going heavy enough to limit you to only 6-7 reps would likely not be a great idea. Conversely, going as low as 6 reps on sets of heavy dumbbell overhead press could be very beneficial for putting on muscle mass.
There are always exceptions, but a good rule of thumb would be to apply myofibrillar hypertrophy training rep ranges to compound, multi-joint movements, while sarcoplasmic hypertrophy rep ranges are best applied to isolation movements. The specific application can vary a little from muscle group to muscle group, but doing 1-2 exercises for sets of 6-10, then following up with another exercise or two for sets 12-15 or more can be a very well-rounded, effective approach for putting on size.