Why You Should Get Jacked Before You Get Shredded [Science]

Chapters:

00:00 Intro

00:27 Does muscle growth CAUSE fat loss?

03:46 My Online PT Course

04:17 Strength vs endurance training for fat loss

07:04 Conclusion

08:35 Outro

Transcript:

A new scientific review found that any intervention that causes muscle growth tends to cause an unintentional amount of fat loss as well. The greater the muscle growth, the greater the fat loss. This goes for high protein diets, drugs like growth hormone and exercise interventions. It applies to humans and to animals. The researchers therefore argue that muscle growth inherently seems to cause fat loss, as if the body is trying to maintain a certain weight.

This fits with research exploring that we have a “gravitostat”, which means that the body tries to maintain a certain weight and therefore interventions like wearing a weighted vest cause fat loss. However, I’m very skeptical of any mechanism that does not involve simple energy balance. Ultimately, the body has to adhere to the laws of physics, specifically thermodynamics, which means that ultimately energy balance has to apply. Energy intake versus energy expenditure is the key variable that determines if you’re going to lose fat or not. All of these interventions either reduce energy intake and or increase energy expenditure. In the case of fat loss from wearing a weighted vest, for example, this can simply be explained by the higher energy expenditure of lugging around all that extra weight all the time.

Nevertheless, I wholeheartedly agree with the authors that muscle growth is highly underrated for fat loss and almost anyone interested in fat loss, even if they are not specifically interested in getting more muscular should actually train for muscle growth for 3 reasons.

First: How lean you look is a matter of your bodyfat percentage, not your absolute fat mass. If you saw my recent video on how body fat percentages look, you will see that muscle mass has a very big impact. A man with 15% body fat with a lot of muscle mass and a man with 15% body fat without a lot of muscle mass look very differently indeed.

Second: Many people massively underrate the effect of nutrient partitioning. When you lose fat and your energy intake is lower than your energy expenditure the body has to fuel that gap by burning energy, burning some of its tissues to produce that energy. if you’re on a good high protein diet with a strength training program what the body burns should be fat loss. If, however, you’re just doing cardio or you’re only dieting, most people lose about 25% of their weight in the form of fat free mass, mostly muscle mass. Any muscle that you lose is fat that you don’t lose. You only have to burn that, say 500 calorie deficit once. So if part of that is muscle loss, that is fat that you’re not losing.

Now again, coming back to body fat percentage, this is a double negative because you now end up with both less fat free mass and more fat mass compared to the person that lost all their weight in the form of fat.

Third: Unlike cardio, strength training that causes muscle growth is a long term investment into increased energy expenditure. When you’re doing cardio, yes, you increase energy expenditure acutely, maybe you burn some 300-500 calories that day, but it’s immediate effort and you get only some fat loss that day if that translates into an energy deficit on that same day. With strength training you not only have acute energy expenditure, you also have long term energy expenditure because muscle growth is a very energy intensive process. Over the coming days ahead it burns some energy and as you build more muscle mass your resting energy expenditure also increases. Now, in the short term, having 1 pound extra muscle mass does not have a big effect on your resting energy expenditure. However, when you look at total daily energy expenditure the effects are more pronounced because it’s not just one extra pound of muscle that’s just laying there doing nothing, you’re also lugging it around the whole day, and while you are moving, it is active and also expanding energy.

It’s no surprise then that fat free mass is the number one determinant of people’s energy expenditure. And if you look at studies that measure the effect of differences in fat free mass between individuals, specifically muscle mass, and look at how different their total daily energy expenditure is, it can easily be some 5%, and in the long term, with a lot of muscle growth, research findings have been up to 20%. That is a very substantial amount of extra energy expenditure that is there to stay without having to do anything specific for your diet, as long as, of course, you keep strength training. These mechanisms can explain why muscle growth tends to cause fat loss, even when people don’t intentionally change their diet.

These mechanisms can also explain the results of the second new study I have for you today. A meta analysis of 31 studies concluded that strength training is as effective as endurance training at lowering your body fat percentage. In studies where the workload was equated, meaning energy expenditure from the workout itself was equal, strength training was also equally effective to reduce absolute fat mass. In multiple studies and some prior meta analyses strength training even outperformed cardio for fat loss. This is especially likely in longer term studies where the accumulated advantage of having more muscle mass starts to show. This knowledge has two major practical implications.

For one, everybody should be doing strength training, even if their goal is primarily fat loss, not muscle growth. At a minimum, you need to preserve your fat free mass to make sure that all the weight you lose is actually fat mass and not muscle. Second, the more muscular you get, the easier it becomes to get to a certain target body fat percentage. For this reason, for many of my clients and students that do not yet have a lot of muscle mass I advise not going all the way down to their target body fat percentage the first time around, because first of all, you’re just going to look anorexic and it’s going to be much harder. What usually works very well is that you get to a body fat percentage that you’re comfortable with, that works well and is convenient, and then as you progress over the course of a lean-bulk cycle, when you have more muscle mass, it will become easier the next time around to get to a new low in terms of body fat percentage.

Another reason to get jacked before you get shredded is that we have an essential body fat level, and this is mostly an absolute amount of body fat. See, our bodies need a certain amount of fat in the nervous system and in various organs to function well. Even if you only care about your body composition at very low levels of body fat our sex hormone production takes a nosedive. That’s why natural bodybuilders on stage often have castrate level testosterone levels. Even though at that point they may look their best, they probably feel their worst. The more muscle you have, the more fat you can also have while still reaching your target body fat percentage, and therefore it gets easier to get lean in a healthy and sustainable manner. All of this said I’m not advocating for a dreamer bulking until you’re obese.

As a concrete rule of thumb I think that even male novice lifters should be able to get to about 15% body fat, even if they don’t have a lot of muscle mass. For women that’s around 25% body fat. Intermediate level trainees should be able to get down to about 10% body fat if they’re male, or around 20% if they’re female. Getting to lower levels then this is something I generally only recommend for advanced trainees that have a substantial amount of muscle mass, or people that already know that they have all the muscle mass that they want because, of course, not everybody wants a lot of muscle mass. It’s also important to note the flip side. Getting to very high body fat levels is not recommended either. First and foremost for your health and vitality, but also because multiple studies have shown that overweight individuals have worse recovery capacity compared to healthier weight individuals. I discussed the potential negative effects of high body fat percentages on your ability to build muscle in this video. So what does all this mumbo jumbo mean in practice for you on your weight loss and long term fitness journey? I think most of the audience will fall into one of two categories.

Category one, probably mostly women that mostly care about fat loss. Then the take home message here is that you should be doing strength training at least enough to maintain muscle mass, and it’s good to realize that getting to a low body fat percentage is much easier when you also build some muscle. Most people that want a certain lean look actually want both more muscle mass And more fat loss, which is what many lay individuals would call “toning”.

The second category would be my main audience, people interested in a lot of muscle mass and a very low body fat level. For you what I recommend to most of my students and clients is to get down to a body fat percentage you are happy with, but probably not your long term ultimate “this is how shredded I want to be” body fat level. And then after the cut you do a lean bulk with mini cuts along the way to keep you around the same body fat level, building some muscle, leaning out a little bit to get rid of the excess fat gain, building some more muscle, leaning out a bit, staying at a similar body fat level, and then long term, as you get more and more muscle mass, every cut can progressively get you down to a lower body fat level. So long term, you’re basically alternating between reaching PRs in your total amount of muscle mass and PRs in your low amount of body fat. This means that every cut phase you should ideally end up at a slightly lower body fat percentage. This works well because you have more muscle mass, and it also works well because you have more experience with dieting.

Note that most of this is ultimately a matter of personal preference, but I think it helps to have some framework to guide your decisions.

I hope this knowledge helps you plan your long term fitness journey, gives you more of an idea of what you can expect, and helps you decide what you should cut or bulk. If you like this type of evidence based information I’d be honored if you like and subscribe. And if you want to geek out on everything there is to know about building muscle, losing fans, and getting stronger, then check out my online course. The link is in the description. Check it out.