I made an observation in the gym this week as I was training, resting between sets, etc.
Most people rest way, way too long between sets. This thought came to me when I realized I had done four sets and completed an exercise in the time another guy had done one.
Listen, if your goal is hypertrophy, you can’t be sitting around for five minutes between sets. You want incomplete recovery, not more than enough for three people.
Now I’m not saying this is what you should be doing for ALL of your work sets, but the latter 1/2 to 2/3s of your workout, your rest intervals should be on the shorter side.
I won’t get too much into this here, but in short you’ve got two types of hypertrophy you can stimulate; one, myofibrillar and two, sarcoplasmic. The former is legit growth of the contractile elements (adding sarcomeres). In contrast, the latter, is the growth of all the non-contractile elements (glycogen, collagen, etc).
The best way to stimulate the growth of the contractile units is through mechanical tension (myofibrillar growth); that is, heavy weights/lower reps. You want to get stronger and thus apply more tension to your muscles over time. And of course, to use heavy weights, you obviously need to be resting sufficiently between sets.
BUT, this is not going to optimize your gains if this is ALL you do.
The best way to stimulate the growth of the non-contractile elements (sarcoplasmic growth) is through the pump/cell swelling, metabolic stress, etc. Think of that pain and burning feeling you get that you try to push through as metabolic byproducts accumulate in the muscle. Of course even here the mindset should still be to get stronger and add weight over time, but the how-to here is different than with the heavy, low-rep work. Here you’re focusing on moderate to high reps, longer eccentrics and time under tension, constant tension, shorter rest intervals for incomplete recovery, etc.
Basically think of the heavy work that starts your workout as “strength training” and the secondary work that finishes it as “bodybuilding training”.
So, to recap, the best approach to building muscle is likely going to be a combination of the two. You’d want to start your workout with a big, heavy compound movement for a given bodypart (squats, bench, rows, shoulder press, deadlift, etc) and your focus is simply to get stronger over time. Reps are low, rest is long. For example, a 5×5 set up works here.
After the heavy/strength training work is done, you move onto your “bodybuilding work” and train in the moderate to high ranges, with shorter rests (30-90s let’s say), maybe some added intensity techniques, etc. This is where you’re adding the volume and is typically where you’re using more “targeted” exercises to hit muscle groups.
It’s this second part you really don’t often see trainees doing right. Stop resting so long!