BEST rep range to build muscle faster!

When it comes to going to the gym, people will give you the classic rep range to build muscles. I’m not sure about you - but I was taught this when I was younger and it was even taught when I went to get qualified as a personal trainer. And here it goes:

15 reps - Endurance

6-12 reps - Muscle Building

4-6 reps - Strength

It’s now 2021 (upon writing this blog) and we know this is FALSE. No one rep range will build muscle and the other doesn’t.

Think about it - if I were aiming for a 12 rep set, and I happened to of faulted my weight and failed at 5 reps. Did I only just build strength and not build muscle?! Would not ONE fibre in my body adjusted and make the growth required!? Sounds silly now that you hear it (or read it for this matter).

I want to question this old school thought and say, forget the reps - yes it plays a role but why not look at the sets? Take a look at this study that was done (Bickel, et. al.)

Of 2 groups, aged between older (60-75) and younger (20-35) they had done 16 week intervention of exercise. This is phase 1 where they had done 16 weeks of training for 9 sets per session for 3 sessions per week (27 total sets) and increased muscle mass.

They then continued on to Phase 2 and split the groups as following:

Group A: 3 sets x 1 per week
Group. B: 9 sets x 1 per week
Group C: No exercise

Results:
Group A: Young group (20-35) maintained their muscle mass but older group (60-75) did not.
Group B: Both young and old groups maintained their muscle mass
Group C: Decreased Muscle mass in both groups
BOTH Group A & B maintained their STRENGTH

So what can we take out of this? It’s not so much about the REPS but about the SETS that we do. So stop poking the bear at 4 reps, 6 reps and 12 reps but ask yourself - are you doing the required 27 sets to maintain your muscle mass?

Here’s my solution. If you require 27 sets per week to maintain muscle mass; split this across your 3-4 sessions per week. Now 9 sets sounds crazy to do per session - but don’t forget that compounds and isolations exist. So looking to maintain muscle mass in your arms? Don’t forget that rows, lat pulldowns and chin ups would be included in this movement.

Bonus: Now it’s hard to ask, what do I do for the weights and possibly even the reps for each of these days? Try this - do all sets to a given intensity or RPE (Also known as reps in reserve). I recommend doing a weight or intensity where you can do 2 reps left in the tank in the given rep range.

For reps given in per day; try high reps (12-15 reps) on a Monday, 10-12 reps on a Wednesday, 6-8 reps on a Thursday and 4-6 reps on a Saturday. That is just a rough idea but it covers all your bases in weights and rep ranges!

Sean Koh

Exercise Physiologist, Exercise Scientist, Personal Trainer & Strength Coach

Post Graduate Diploma (Exercise Physiology) & B.Sc. (Exercise, Sports & Rehabilitation)