The Most Overlooked Training Principle for Muscle Size

I’ll spare you the normal intro B.S. and get right to it. The most overlooked training principle for putting on real muscle size is rest periods between sets. Pure and simple. Maybe you or someone like you is guilty of not following this hallowed rule?

I was for the longest time. When I was younger I was more focused on lifting heavier and heavier. Of course I wanted to get stronger. Who doesn’t? But I was sacrificing more size for strength. I was well entrenched in the strength game. Who could blame me? I was young and enthusiastic to a fault.

Over the years I tried my best to increase the amounts I was lifting and not really paying too much attention to other factors.

I lifted heavy stuff, used some body English, and kept pushing, pressing, and pulling on all cylinders.

Age, pain, and gains

A funny thing happens when you get older. Your joints start having a say in your everyday activity. Knees become a little stiff, shoulders get cranky, and sciatica rears it’s freaking ugly face.

In my thirties I started to clean up my form a bit. Since I wasn’t competing in bodybuilding anymore I felt the consistent and obsessive drive to always improve to be tamed a bit. I could exhale a little and try a few new things in my training.

For a time perfect form did some good, but some of my joints were still holding a grudge. I was still reaping the euphoria of the iron bug bite, but I had to do something to continue the ride.

I went back to my roots. I once again became a student, studied like a school kid, and buried my ego. I went full-on high rep training with short and strict rest periods.

Then the gains came once again.

Get your head straight and gain some muscle

There are several factors that go into muscular size or hypertrophy. Mechanical tension, muscle damage, and metabolic stress are three of the main components. I’ll go into those more into detail in a later post if you want me to, but for now let’s look at what we can do right now to better position ourselves to pack on more muscle.

The key to your training should be to recruit as many muscle fibers as possible in a given muscle group. Furthermore, you should try to fatigue those muscle groups with appropriate time under tension.

To do this you need to do two things. Increase the length of your sets and reduce the rest time between them.

I’ve broadened my rep range from the traditional 6 to 12 over to 10 to 20 reps depending on what movement I’m doing and what body part I’m training. Plus, I’ve cut rest periods down to 30-60 seconds.

So you’ll see with my current training program I’ve checked both boxes.

The results? More muscle mass, better pumps, and nicer joints. You can’t beat that. The only thing you’ll have to give up is your ego, but I believe that fades with age anyways.


Let me know in the comments if you’ve tried this with your own training.

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11 thoughts on “The Most Overlooked Training Principle for Muscle Size

  1. Thanks for sharing this invaluable information Brad! I have searched and searched for the answer on how to build size, while being smart. I have been left more confused then before..

    I noticed you try to do 30 secs rest for isolation exercises and 60 sec rest for compound exercises.

    Right now I’m doing 60 secs for both. For side raises for example, I feel I need that much rest or my reps will go down too much each set. Would it be better to use a lighter weight to keep up with the 30 sec rest in between sets vs more weight then?



    1. Hi Nick. First off, if something’s working for you then don’t change it. However, if not then I have a few suggestions.

      I’ve always had difficulty putting on muscle size to my delts. I’ve done the heavy, low rep presses and lateral raises with little-to-no results. Sure, I’ve gotten stronger, but it just didn’t result in size/width. I decided to throw out strength goals and just focus on fatiguing my shoulders with higher reps and very little rest.

      Many times I’ll superset moves like side laterals and bent-over rear laterals with no rest between supersets. I focus on rep goals versus weight goals. The 30 second (or less) rest periods ensure that I don’t feed my ego. And that brings me to my second point.

      Going a bit lighter on shoulders have saved my joints. I couldn’t keep going the heavy route into my 40s and 50s.

      I hope that helped.


      1. Thanks Brad! So progressive overload should still be the goal,? but through reps (fatigue the muscle) first then weight if your at the top end of the range.

        The shorter rest periods help with muscle fatigue and to ensure your forms in check to build size?

        Feel like I’m finally understand this concept!! Only took 2 decades…Haha 🙂 I would really like if you can break down the different concepts if you have time.

        Thanks Brad!


  2. Nick, you’re right. Fatigue the muscle, progressive overload (but only within reason) and use a higher rep range especially if the heavier loads aren’t putting on muscle size. Yes, I do plan to break these things down further in a future post. Stay tuned!

    And please let me know how you do.


  3. Hey Brad,

    What do you think of holding a peak contraction for 1-2 sec for every rep? I find this easy on the joints, have to use much less weight though… but then again, I’m not trying to be the strongest guy in the gym anymore “I want to build muscle” and stay in shape these days.But with the reps in the 12-20 range, is this necessary?

    Obviously, progression is much more difficult with this method but it seems to really make the muscle burn.

    Just wanted your thoughts!


    Liked by 1 person

    1. Well, you and I think alike. I’m more interested (at 46) in building muscle. My max bench press and squat days are done — but, I’m totally good with it.

      I’m all about finding ways to make lighter weights feel heavy. Time under tension and muscle fiber recruitment and exhaustion are key factors in building muscle tissue. So anything to get to those states are worth it. That’s why I like the 10 to 20 (ish) rep range. I can fatigue the muscle with lighter weight. My joints feel fine and I get crazy pumps.

      I think holding a contraction for some exercises is a great way (among many) to fatigue and recruit more muscle fibers. It increases time under tension so you cover that base, and if it feels better on your joints then go for it. Just track your progress and make small adjustments along the way only if necessary.

      Good luck!


  4. You are really on to something with this article. TUT and progressively overload when you can has been helping my goals (purely hypertrophy). I try to make my sets last atleast 40 sec, so 1 sec concentric and 3 sec eccentric.

    Been reading a lot of articles by Steve Holman and enjoy using his 4X style of training. Dude is still jacked in his 60’s.


  5. Hey Brad,

    How do we keep progressing to build muscle when the rest periods are 30-45sec for isolation exercises and 60 sec for compound exercises?

    This has been great for my joints and I love the pump, but dont we still need more load over time? Initially, I can see this helping to build muscle but we cant keep just lifting the same weight, no matter what rep range we’re using right?

    Absolute strength isnt my goal, building muscle in my 40’s and beyond is but there has to be some level of progression even if your doing 15-20reps to failure?



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