T Nation

Ideal BF Percentage for Maximal Muscle Gains


Dear CT,

Just had a question on your opinion of what body fat percentage one should carry to maximize their hypertrophy from weight training.

Thanks in advance,



Hard to answer exactly.

Being leaner helps because it makes you more insulin sensitive. And if you are more insulin sensitive you tend to more easily use nutrients to build muscle or glycogen stores rather than gain fat.

But on the other hand if you are "too lean’ cortisol levels can stay more elevated while testosterone can drop down (when that happens you will have a drop in libido).

But I actually do not think it might be the fact that you are “too lean” that is the root of the problem, but rather what you do to be that lean. For example consuming very low carbohydrates can lower IGF-1 levels and well as have a negative impact on mTor, both of which will hurt muscle growth.

So my answer would tend to be “the best body fat percentage to gain muscle is the leanest you can be without having to maintain a caloric restriction and that doesn’t lead to a drop in libido”…

For some people that might be 7% while for others it will be 12-15%.


Had my BF tested - water tank (managed to get it as part of my medical insurance health check)

10.8% - have visible abs (bit blurry definition in lower) . This seems to be my sweet spot in regards to performance (resistance/metabolic training + Muay Thai), as well as my ability to handle carbs as well as my general well-being/feeling good.

To augment CT point in regards to low carb diets - FOR ME 300g carbs a day, 160g protein and fats from fish oil/protein (3000cals total) works far better at this BF than the same amount of overall cals - Higher fat, lower carbs.

In my experience, when you get to a lower bf and maintain your set-point for 1-2 months, it’s easier to maintain that bf + re-comp in the long run.

I’ve totally changed my opinion and stance on carbs…I rarely go below 150g, even on off days, and do ‘diet’ anymore - I eat and train for performance and adjust depending on my current goals.

Never felt and performed better and I’m 39 next month ;0)