Can you build muscle on a ketogenic diet?
Absolutely! There’s a common misconception in the athletic and bodybuilding world that it’s difficult to build muscle when you’re in ketosis.
The truth is that high-fat, low-carb diets like the keto diet are excellent for building muscle, as long as you pay attention to a few key guidelines.
Let’s take a look at how muscle building works, what you need to put on muscle mass, what your protein intake should be for muscle gain on keto, and the best kind of training for a ketogenic diet.
Before we talk about actively building muscle on keto, let’s address a common myth: a ketogenic diet doesn’t make you lose muscle mass.
Some bodybuilders and weightlifters worry that going keto will cost them their precious gains, but research suggests just the opposite. A recent study found that, while a lot of people lose weight on keto, almost all of that weight loss comes from fat stores[*]. In fact, keto may even preserve lean body mass, preventing muscle loss while you lose body fat[*].
Another study found that people who went keto actually gained muscle mass while losing fat[*], which leads into the main point of this article: it is very possible to build muscle on a ketogenic diet.
To build muscle, you need four basic things:
You need something to stress the tiny fibers that make up your muscles. Under enough stress, your muscle fibers tear, and when your body repairs them, it builds them back up larger than they were before. This process is called muscle protein synthesis, and it’s the basis for muscle gain.
In order to trigger muscle protein synthesis, you need to tear your muscle fibers. That’s what exercise does — it breaks down your muscles so they build themselves back stronger.
Your body uses amino acids to repair and rebuild your muscles. Amino acids are the building blocks of proteins, and you need to get several of them from your diet. That means in order to build muscle, you have to eat plenty of high-quality protein.
If you’re in a deep calorie deficit, your body will struggle to put on muscle. Instead of spending calories (and protein) on building lean mass, your body will put those calories toward running basic biological processes you need to stay alive.
If your goal is fat loss, a moderate calorie deficit is great — but if you want to put on lean muscle, you should eat at least as many calories as you burn, if not slightly higher. You can use this keto macro calculator to figure out how many calories you should eat to build muscle.
After all that hard work, your body needs time to rest. Hormones play an essential role in muscle gain because they signal to your muscles to start protein synthesis. Strength training triggers all the right hormones for building muscle, but it’s during recovery that you really get the hormonal shifts that help you put on lean mass.
For example, you release a sustained, massive amount of human growth hormone (which triggers muscle growth and repair) during deep sleep[*].
If you’re chronically stressing your body, either through overtraining or poor sleep, you won’t put on muscle as quickly. Rest days are as important as training sessions.
These are the four ingredients for building muscle: exercise, protein, sufficient calories, and recovery.
It’s easy to overcomplicate these things. Building muscle is simple, although it takes consistent hard work to do it. Just work hard at the gym on a regular basis, eat plenty of protein and sufficient calories, and prioritize rest when you aren’t working out.
As long as you get enough protein, your carb intake has no impact on muscle building, whether you’re eating keto, low-carb, or high-carb.
Several studies have found that carbohydrates don’t affect muscle growth[*][*][*]. Other research has found that people can do intense exercise while in ketosis[*], and that it’s perfectly possible to gain muscle on a low-carbohydrate ketogenic diet, as long as you get enough protein[*]. You can build muscle on keto with no problem.
In 2016, researchers ran a study to see how people who are doing intense weight training respond to different amounts of protein. They found that the ideal protein intake for muscle gain is 0.8 grams of protein per pound of bodyweight[*].
A 200-lb. person, for example, would want to eat 160 grams of protein per day. The study found no benefit to eating more protein than 0.8g/lb. bodyweight, and slower muscle gain eating less than that.
That’s a fairly large amount of protein, especially for a keto diet. You may have heard people say that you want to keep protein low on keto and focus mostly on fat intake instead.
You also may have heard that if you eat too much protein, you’ll trigger gluconeogenesis, which is when you turn protein into sugar to fill up your glycogen stores and muscle glycogen, taking you out of ketosis.
Fortunately, gluconeogenesis is not really a concern on keto (here’s why). You can eat a high-protein keto diet and be just fine.
To feed your muscle cells and put on lean mass, aim for 0.8 grams of protein per pound of bodyweight.
There are two kinds of training that are especially anabolic (i.e. they trigger muscle growth): resistance training (weightlifting) and high-intensity interval training (HIIT).
In other words, to put on muscle, focus on lifting heavy things and/or sprinting. Heavy lifting 3-4 times a week is ideal, but if you’re new to the gym, start at 1-2 times a week and work your way up. The goal is consistency — find a schedule you can actually stick to long-term and do it successfully for a few weeks before you start adding more workouts.
As an extra bonus, you can add in a session or two of HIIT each week. HIIT takes no longer than 20 minutes, which is nice, but it’s incredibly intense, and should push you to your absolute physical limits.
You can find plenty of free strength training and HIIT workout plans online, or you can work with a personal trainer. If you’re a beginner, this keto workout plan is a good way to ease into the gym.
Some athletes find that they struggle with energy while on keto, especially if they’re working out almost every day. If you find yourself exhausted mid-workout, you may want to try a targeted keto diet.
Targeted keto is a variation of the standard keto diet designed for athletes. It involves eating slightly higher-carb before your workouts. The idea is that your body will burn through the carbs while you exercise, giving you extra energy, and then will go back to ketone production shortly after you leave the gym.
If you’re running out of energy during strength training or HIIT, check out this guide to targeted keto.
Building muscle on keto is simple: exercise (preferably weight lifting and/or HIIT), eat enough protein and calories, and get plenty of rest between workouts.
As long as you do those four things, keto dieting won’t ruin your gains or slow down your progress in the gym — in fact, it may even speed up fat burning and help you get into the best shape of your life.