Full-body training DOMINATES to build muscle

Chapters:

00:00 Intro

00:29 Fatigue, recovery, and rest between sets

01:20 Spreading training volume across the week

02:10 Two studies on training frequency

02:39 Study 1: Flywheel leg presses

04:11 Study 2: One leg day versus three

05:41 What changes when work volume is matched?

06:29 Diminishing returns from more sets

07:41 Saving time with combo sets

08:51 Why full-body training is the dominant option

09:23 Why body-part splits became popular

09:56 What soreness and the pump tell you

10:33 When a body-part split can still work

11:01 Outro

Transcript:

The best way to build muscle is to train every muscle group that you care about every time you go to the gym. This is what I personally do, and this is how I got most of my client results.

Many people will say this is crazy because how could you possibly recover if you trained a muscle group just the last day or two days ago, and now you’re going to train it again? Well, actually, counterintuitive as it is, but you get much better recovery with full-body workouts and high-frequency training than with split routines.

To understand why, first, definitions. Fatigue in exercise science is not some vague term. It is the loss of force production in a muscle group which corresponds with loss of mechanical tension, which is what you need to stimulate muscle growth. Recovery means that your force production gets back to baseline. It’s the recovery of the force production in the muscle group.

Most of this recovery takes place within minutes, not days. You can readily observe this yourself with your rest intervals. The number of reps that you can do goes down very fast if you only rest, say, a minute after your set. But if you rest two minutes, you already can recover a substantial amount of your reps. And then if you rest more than, say, five minutes, you get very, very little additional recovery for your time. That’s because most of the acute fatigue is due to metabolic stress and energy depletion, both of which recover within minutes.

And if you logically think about it, your rest interval and your training frequency are the same consideration. It’s how you distribute your training volume over time. The more you spread out your volume across the week, such as by training with a higher training frequency, which is typically done by full-body workouts, the easier you recover, because the less time you spend in an extremely fatigued state.

If you normally do ten sets of chest work on one day, if you spread out those sets across the week, you are much more recovered when you do those sets, not less. The most fatigued time you will ever be for your 10th set of chest work is right after nine sets of chest work. Moving that set to any other day of the week will make you much better recovered. You can easily see this for yourself. You can do more repetitions or lift more weight when you move that set from your chest day to a different day.

Two new studies suggest that this extra performance you get from spreading your volume out more equally across the week increases muscle growth. These studies are particularly relevant for serious lifters because both of these studies were done in trained individuals, and in both of these studies, the set volumes were equated, but the total work volumes were not.

Many studies on training frequency also equate total work volume, which means that the group with a higher training frequency trains a bit less hard to make sure that they don’t do more reps than the group with the lower training frequency.

In the first new study, a group of 30 trained lifters did maximum-effort leg presses either as five sets one time per week, or as one set five times per week.

Five sets a week may seem like a very low training volume, but the leg presses were performed with flywheel loading. Flywheel loading is a sort of eccentric overloading. It’s technically debated if it is true eccentric overloading, but regardless, it is a very brutal form of training that is much harder than a standard leg press.

After just six weeks, there was a clear trend of superiority for all measures of muscle growth and strength development in the group doing five sets spread across the week instead of five sets in one session. I would note that the between-group differences were not statistically significant, but they were significant in one group and not the other group, and the difference is likely caused by low statistical power. It’s a six-week study in trained individuals, so we have to go by the trend.

And the higher frequency group achieved this trend of better gains with less muscle soreness and lower perceived exertion per workout. This makes perfect sense. It’s much easier to do more short workouts than to do one longer workout. The more fatigued you get, the more people typically want to rest within a workout, and the more the mental fatigue really accumulates in the session. If you do short sessions, you are basically fresh for the whole session. So most people find that spreading their volume out across the week also helps with mental effort and with being less sore.

This was just one study, and it’s not exactly how most lifters train. So let’s look at another new, more representative study. In this second new study, 18 strength-trained men performed a somewhat typical leg day consisting of nine sets of quadriceps work, all performed to failure, consisting of squats, leg presses, and leg extensions. One group did the leg day with nine sets to failure on that one day. The other group did three sets, three sets, three sets spread across the week.

Again, after just six weeks, all measures of strength and size favored the higher training frequency group, and because it was another short study in trained individuals, the differences didn’t reach statistical significance. However, for the strength gains in the squat and the leg press, there was a trend towards statistical significance, with a p-value of 0.07, just short of statistical significance.

Neither study on their own was particularly compelling from a statistical sense, but combined with the theoretical rationale, it makes a lot of sense that spreading your volume out across the week increases performance and therefore allows you to put more tension on your muscles, which is a stronger signal for muscle growth.

Indeed, in the second study, the researchers measured that total work volume, which is sets times weight times reps, was considerably higher in the group doing three workouts compared to the group doing everything in one leg day.

And if you logically think about it for yourself, how effective are your leg extensions when you just did squats and leg presses in that same session, three sets each? Not so much compared to when you do them on a separate day and you’re still fresh. You can do a lot more repetitions, which is more tension on the quads. Tension is what drives muscle growth.

These results are also very similar to a previous study, in which they had one group doing all of their training in one session, one group spreading it across three sessions, and then another group spreading it across three sessions, but limiting the volume to be the same as the group doing it all in one workout. They saw that when the volume was distributed across the week more equally, there was again a trend towards greater gains. However, when you spread the volume out across the week but the total volume, meaning the total repetitions, was kept the same by training a little bit less hard with the higher training frequency, the results were similar, so they did not have better gains.

This shows that it’s not the higher frequency per se that increases your gains, but the additional higher volume that you get, specifically the repetition volume or the higher weights that you can lift. That’s what’s driving the additional muscle growth, most likely.

I also recently covered a new meta-analysis showing that when your volume exceeds ten sets per muscle group, there appears to be very limited additional muscle growth that you get. This also makes perfect sense in light of the diminishing returns to volume. After your tenth set, you are mostly just fatigue maxing and not contributing a lot of additional stimulus for muscle growth, because fatigue is so high that you can put very little additional tension on your muscles. Also, probably at some point your body just gets the hint.

If we combine this with the total literature, it’s clear that volume is king. Set volume is particularly important, and repetition volume is of secondary importance. When you distribute your volume across the week, you only get potentially greater gains if this results in a higher repetition volume, or you can use higher weights.

In most studies, there is no significant difference in muscle growth between higher and lower frequencies. However, when we specifically look at studies like the two new studies in which the higher frequency groups can do more volume, specifically more repetition volume or lifting higher weights, we do see some trends towards greater gains. And in all relevant comparisons, higher frequency training results in better or the same amount of gains. And this is achieved with less soreness and less effort.

Another, perhaps in practice, even greater advantage of full-body training is that it’s dramatically more time efficient. if you set up your workout well and you use combo sets or supersets. When you do squats, you can easily do dumbbell overhead presses and chin-ups in the rest interval of your squats. It’s a bit more effortful, but most people rest some five minutes anyway in between their sets of squats, so you might as well do another exercise in that period. If you do even just one exercise, it literally cuts your workout time in half because now your rest interval double-times. It serves as a rest for both the squat and the dumbbell overhead press, so you can easily cut your workout length in half by strategically combining different exercises that have importantly non-overlapping muscle groups.

You cannot do this with most upper/lower splits or push/pull/legs splits. Body-part splits like push/pull/legs are particularly horrible in terms of time efficiency, because there is no way you can do any exercise until maybe the end of the workout with some isolation exercises where you do a different muscle group because you’re only training the same muscle groups in the same session. Full-body splits make this very easy, allowing for much greater time efficiency. If you’re interested in optimizing your combo sets in more detail, I already have a video on that here, so I won’t go into it further right now.

The key take-home message here is that full-body splits are the dominant option to build muscle mass. A dominant option is a term from economics, which means that the option is equal or better in every regard. Full-body training is significantly more time efficient. It results in a better stimulus-to-fatigue ratio, at least as assessed by perceived exertion and muscle soreness, and it results in at least the same amount of gains and in many studies, better gains, especially in trained lifters doing higher volumes, and especially if your volume otherwise exceeds ten sets, per muscle group, which is pretty typical in most bro splits.

So if it’s the dominant option to spread your volume more equally out across the week, which is done by full-body workouts, and these are significantly more time-effective, you have slightly better gains, and you have a better stimulus-to-fatigue ratio, why do none of the pros implement this? The answer is that actually, all of the pros implemented full-body training splits during the natural age of bodybuilding up until about the ’50s. Virtually all of the Bronze and Silver Era natural bodybuilders built their physiques on full-body workouts. It’s only after the 50s when steroids came around that split routines became more popular.

Split routines feel like they should be more effective. You get a lot more sore after the session. You get much more of a pump during the session, so it feels like a lot more is happening. However, logically, that is just fatigue maxing. Research is very clear that metabolic stress or the pump are not significant drivers of muscle growth. Only mechanical tension is. And soreness, insofar as this even represents muscle damage, is probably undesirable.

If anything, you want the least amount of muscle damage for the most amount of mechanical tension. But by and large, muscle damage is just a byproduct, and soreness isn’t even a good indicator of muscle damage to begin with. It’s just a nuisance.

Now, if you value the pump in itself, you just like the experience or you like being sore, there is a perfectly valid reason to stick with a body-part split. And if time efficiency is not an issue, then you also don’t benefit in that sense. If you just do enough volume, any split you do can work.

It’s mostly about volume and effort, but the logical answer if you want to optimize your routine, you want a better stimulus-to-fatigue ratio, much better time efficiency, and probably slightly better gains, then full-body splits are the answer.

If you want to see what an optimized full-body training program looks like, you can get a free trial to my MH Physique app with the link in the description. Check it out. See you next time!