If you’re serious about bodybuilding, you can’t ignore Brad Schoenfeld. This American scientist has numerous studies on muscle growth to his name, which have helped shape our contemporary understanding of training and nutrition. So it’s always interesting when he has his say in a podcast, like recently with YouTuber Abel Csabai. We highlight three interesting questions; you can find the entire podcast below.

6:25 – WHAT ASPECTS OF MUSCLE GROWTH HAVE YOU CHANGED YOUR MIND ABOUT OVER THE PAST TEN YEARS?

There has been a tremendous amount of research into muscle growth over the past decade — much more than in the decades before. As a result, we learn more and more about how muscle growth works and how we can optimally program training, nutrition and recovery. However, scientific guidelines always remain general; each individual reacts differently. In addition, hereditary conditions play a major role in bodybuilding.

We have become wiser on many points in recent years, but I think the most important are these:

1. REPRANGE

I also used to think that there was a ‘hypertrophy range’, of roughly 6-12 repetitions, which is optimal for muscle growth. Science has now proven more than enough that the number of repetitions does not matter, as long as you train a set until (near) muscle failure. So in theory you can achieve optimal muscle growth with every rep range, although 6-15 repetitions is the most ideal for practical reasons.

More research is needed on the need for fiber type specific training, in which you complete a small portion of your training with low weights and many repetitions, to optimize the ‘slow’ muscle fibers (type I, or slow-twitch) to stimulate.

2. REST TIMES

We used to think that for muscle growth it is best to use short rest times between sets (~1 minute). Taking a short break means more metabolic stress and more acute hormonal response. The influence and thus the importance of that hormonal response has in itself been weakened by several studies. But there are now also various studies that make it plausible that it is better to rest a little longer between sets. Metabolic stress comes at the expense of weight (mechanical tension) and/or repetitions (volume). And mechanical tension in combination with volume appears to outweigh metabolic stress for muscle growth.

Advice: rest at least 2 minutes between sets for compound exercises and possibly a little shorter for isolating exercises.

3. BRO SPLITS

I am no longer in favor of bro splits (only training one muscle group per session, ed.). Although training frequency in itself does not induce extra muscle growth (see below, ed.), I think that you can better spread your training volume from a certain amount (8-10 sets per muscle group) over several sessions per week.

10:23 – ACCORDING TO A (CRITICIZED) STUDY OF YOURS, 45 SETS PER MUSCLE GROUP PER WEEK LEAD TO MAXIMUM GAINS . ISN’T THAT A LOT?

This requires nuance. The study in question mainly shows that there is a clear dose-response relationship between training volume and muscle growth, while such a relationship hardly exists if you train for pure strength. If you only want to get stronger (and therefore not necessarily more muscular), you will arrive with little volume.

As for those 45 sets: this only involved one muscle group (the legs). For the rest, the subjects in the study trained at fairly low to medium volumes. The largest total volume was 100 sets per week, which is rather on the low side for many bodybuilders. Apparently you can use a very high volume for one muscle group, provided your total volume remains within limits. I would also like to note that the study lasted eight weeks; so we don’t know what such a high volume will bring about in the longer term. In addition, the subjects were young men of around 20 years of age, which means that they naturally had a high recovery capacity.

Just as practical: I think the optimal weekly number of sets for muscle growth is somewhere between 10 and 25 per muscle group. There is already enough research to prove that. My research shows that you can also go above 25 for a certain period, provided the total training volume is adjusted accordingly. If a certain muscle group remains behind, you can train it for a while with a higher volume, provided you train the other muscle groups at a lower volume (minimum maintenance volume, ed.).

Moral of the story: the maximum training volume per muscle group should be seen in the context of the total training volume. In my opinion, for example, overtraining is not caused by training one muscle group, but is the physical reaction to too much training in total.

32:15 – HOW IMPORTANT IS TRAINING FREQUENCY IN RELATION TO TRAINING VOLUME?

In my recent meta-analysis, we found that a higher training frequency on its own fuels little to no additional muscle growth. If the total weekly training volume is the same, in principle it does not matter whether you complete it in one or two sessions per week.

It is not yet entirely clear how this applies to higher training volumes. I want to investigate that further in the near future. For now, I recommend doing a maximum of 8-10 sets per muscle group per workout. Do you do that in one weekly workout? Fine. But if you want to do more sets for that muscle group on a weekly basis, it is better to spread the volume over two training sessions. After all, the more volume you put into one workout, the more that can be at the expense of your volume load, the number of repetitions you can do with a weight. In addition, you can only recover from a certain volume per workout.

THE PODCAST

Subjects

00:30 – Intro questions (Brad’s background, his current contritution to the field, etc.) 06:25 – The fundamentals of muscle building (his view on this now verus ten years ago) 10:23 – Discussing the findings of the recent 45 sets/week study 15:10 – Real life applications of the study 18:53 – The impact of training your whole body versus just only a few muscle groups with so much volume 21:42 – What would have happened if the study ran for longer? 24:50 – Did swelling inflate the results? 26:50 – The importance of absolute load and junk volume – an interesting back and forth here 32:14 – Touching on training frequency 34:50 – Targetted muscle fiber training 40:50 – Effective reps and new ways of quantifying training volume 44:00 – Where can we find out more about you?