Conventional thinking tells us that adding more weight instead of more reps is always the way to add muscle, but a new study says otherwise.
I’m calling Milo out. You know the story, the one about the guy carrying the bull? It’s a little off.
As you probably know, Milo has been called “the father of progressive resistance training.” Way back in Greece in the 6th century BC, Milo picked up a newborn calf, hoisted it onto his shoulders, and walked around with it until it was time to go to his aunt’s house and clean the leaves out from the Corinthian columns in front of her temple.
The next day, Milo picked up the calf again and walked around some more. Same thing the following day and the next. He must have figured it would make him a stronger wrestler, so he kept on doing it. Meanwhile, the calf kept putting on weight. Soon, it’s a full-grown bull, and Milo is still toting him around like Bob Cratchit carrying around an enormously bulked-up and no-longer-tiny Tim.
Yep, there it was – progressive overload in action.
Modern-day folk marvel at this tale, especially when we consider that bulls weigh between 1,100 and 2,200 pounds.
That’s what caused me to become suspicious. Even Tom Stoltman, reigning “strongest an in the world,” couldn’t hoist a piece of meat that size onto his shoulders without a crane, let alone carry it down to the Acropolis.
I did a little sleuthing, and it turns out that prior to 1790, at least in America, beef cattle averaged only 350 pounds. Hell, all it takes is a little extrapolation to figure out that Milo’s bull probably weighed no more than Mrs. Papadopoulos’ poodle, Dimitri.
Okay, I’m exaggerating. Still, Milo’s bull was probably nowhere near as heavy as today’s bulls. That means that as the bull reached his comparatively meager adult weight, Milo would have essentially plateaued.
Maybe he decided he needed to do more “reps” with the bull. You know, carry it a bit, put it down, rest, and do it again. He’d probably have wondered, though, if doing more reps with the same weight was as physically profitable as continually adding more weight.
Too bad he couldn’t consult with a group of researchers, Brad Schoenfeld among them, that took it upon themselves to compare the effects of both types of progression. Milo would have realized that both methods appear to be pretty equal when it comes to building muscle.
Schoenfeld and his colleagues, no doubt while drinking lab-brewed beer out of 1000 mL beakers, had an epiphany: They realized that no one had ever conducted a study “designed to directly compare the effects of progressing repetitions vs. load on muscular adaptations.”
They predicted “…that load progressions would produce superior maximum strength and that repetition progressions would produce better muscular endurance.” But it’s a good thing they went ahead with the study anyhow because it turned out they were largely wrong.
Here’s how they figured it out: They rounded up 43 participants (27 men, 16 women) with at least one year of consistent lower body resistance training and divvied them up into two groups. The first group would increase load while keeping reps constant (the LOAD group), while the second would increase reps while keeping the load constant (the REP group).
All the participants were poked, prodded, and tested. They had their 1RM in the Smith machine assessed, their endurance in the leg extension recorded, their countermovement jump height determined, and their muscle thickness of the thighs and calves measured.
Subjects performed 4 sets of 4 lower body exercises twice a week for 8 weeks:
- Back squat
- Leg extension
- Straight-leg calf raise
- Seated calf raise
Both groups began with participants attempting to maintain an 8-12 rep max per set. As training progressed, the LOAD group kept increasing load while maintaining the target rep range. Meanwhile, the REP group attempted to increase the number of reps while maintaining the initial load.
All trainees did their reps in a controlled manner while taking 1 second to perform the concentric action and 2 seconds to do the eccentric action. Sets were performed to the point of momentary concentric failure.
After 8 weeks of training, the researchers repeated all the same poking, prodding, and testing they had prior to the start of the study.
Who’da thunk, but the outcome of REPS training was generally similar to LOAD training:
Both groups gained appreciable muscle over the 8-week training period. Muscle thickness increased in the soleus, gastrocnemius, and all three vastus lateralis measurement sites. However, there was one notable exception: REPS showed a modest advantage over LOAD in the thickness of the rectus femoris.
All participants increased their 1RM squat by an average of 20 kg, but LOAD showed about 10% better results than REPS.
There was no readily discernible difference between the two groups as far as leg extension endurance as both groups increased by about 7 reps.
Neither group improved on this measurement, nor was there any difference in performance between the two groups.
I’ll let the research team say it for themselves:
“Progressing load and repetitions throughout an 8-week training cycle produced similar increases in muscle size in most muscles and regions of the lower body. This suggests that both are likely sufficient for maximizing hypertrophy, at least in the short to medium term. However, we found modestly favorable aggregate muscle thickness measures favoring rectus femoris growth in REPS… Load progressions were slightly more effective for maximal strength and equally effective for muscular endurance performance.”
A lot of you should be excited by these findings. Say you’re injured or have bad joints, or maybe you’ve just plateaued, i.e., are stuck on a weight. It could be you’re an old bastard who gave up on big weights. Maybe you work out at home and just ran out of weights to slap onto the bar.
Regardless, this research tells you that increasing repetitions instead of increasing weight is a viable strategy for getting bigger and stronger, at least for a while.
I think the late Charles Poliquin had long ago suspected these findings to be true. I remember a biceps workout he sometimes used to build strength and promote hypertrophy that somewhat mirrored the findings of the study. It involved using the same load on an exercise while increasing the reps in every subsequent workout. Here’s an example:
- Week One: 4 sets of 4 reps
- Week Two: (same load) 4 sets of 5 reps
- Week Three: (same load) 4 sets of 6 reps
- Week Four: (increase load) 4 sets of 4 reps
- Week Five: (same load as week 4) 4 sets of 5 reps
- Week Six: (same load as week 5) 4 sets of 6 reps
Unfortunately, there’s no absolute way of knowing (yet) whether these findings also pertain to biceps or the upper body in general, but it wouldn’t be too crazy to assume that they do.
But even if you’re a sucker for load, it seems that it would be a good idea to mix it up a bit, allowing yourself cycles where you focused on putting that bull down, resting a bit, and picking it up again for reps rather than being a slave to load.
Make any workout work better. Fuel it.
- Plotkin D, Schoenfeld BJ et al, Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. PeerJ. 2022 Sep 30;10:e14142. PubMed.