Question: What percent body fat is the most anabolic, and where do you feel the best? Is that a good place to start a muscle growth phase?
It’s not the same for everybody. Though technically, the leaner you are, the better your insulin sensitivity. This is important because it improves nutrient partitioning, which will help your body preferentially store nutrients in muscle tissue rather than fat.
Plus, when you’re leaner, work capacity is higher. You’ll also likely recover faster. Blood pressure will be lower, and you’ll probably be less tired throughout the day. If you have an extra 20 pounds of fat on you, it’s like spending the whole day walking with a 20-pound backpack.
However, if you get too lean relative to your natural set point, you can start to have negative adaptations, like these:
- Sex hormones can decrease, lowering your sex drive or even giving you erectile dysfunction.
- Cortisol will increase, making it harder to build muscle and recover from training.
- Leptin may decrease while ghrelin increases, giving you cravings and making you lazier.
- Adrenaline can stay elevated, even in the evening, making it hard to sleep.
So what’s the answer? Get as lean as possible without being too far from your natural set point.
What’s your natural set point? It’s the body fat level that you stay at naturally. When you lose fat, your body will want to get back to what feels normal, and the further away from what it considers normal, the more bad stuff happens to force you to go back up.
Now, being 2-5% lower than your set point is easily maintainable. But when you get down to 6-8% lower than your set point, you’ll start to have negative changes (like those mentioned above). The lower you go, the more of them you’ll have.
For example, if your natural set point is around 18% body fat, then maintaining 13-16% is pretty easy. But if you go down to 10% or less, you’ll begin to have problems.
The good news? You can gradually adjust your set point downwards. The bad news? It takes time.
For example, if your set point is 18% and you go down to 13% but stay there for a long time (if you got there in a sustainable manner), then your body will slowly adjust its set point. After a fairly long period, your set point will now be 13-14% rather than 18%.
This will both make it easier to stay lean and also make it possible to go down to as low as 9-10% and maintain it without ill effects. That’s why I can now stay at 9-10% with very little effort and can be as low as 7-8% and maintain it. But years ago, as a fat Olympic lifter, going down to 13% was uncomfortable.
It takes a long time to adjust your set point. You need to be at a certain level for close to a YEAR for the body to adjust.
And while having a lower set point makes it less likely that you’ll gain lots of fat, you can still get fatter if you eat too much. (When I get above 12-13%, my appetite dies, which makes “bulking” pretty much impossible.) And if you let your body fat creep up higher than your set point, it will readjust back up. Be careful because, sadly, upward adjustment is faster than downward adjustment.
What percentage of body fat should you start your muscle gain phase from? Well, the leaner, the better. First, because of the insulin sensitivity issue. But also because in a proper muscle-gain phase, you’re bound to gain some fat. If you start from a very lean state, you have more leeway to add body fat while still looking good. So it’s perfectly fine to diet down to a bit lower than your “maintainable/comfortable” level and build from there.
