Why low carb bodybuilding (and strength training) is dumb.
By Coach Hunter Bennett
What is low carb?
Over the last few years low carb diets have become very popular. And with the carnivore and ketogenic diets entering the mainstream, it has only gotten more common.
But are low carb diets good for building muscle and strength?
As the name implies, low carb diets describe a way of eating that is low in carbohydrates. Within this, there are two types of low carb diets:
- Low carb diet: where 25% or less of caloric intake comes from carbohydrates.
- Very low carb diet: where 10% or less of your caloric intake comes from carbohydrates.
Pretty simple really.
What are the benefits of low carb diets?
Part of the reason low carb diets have become so popular over the last few years is because they are suggested to have a myriad of benefits.
These include weight loss, improved cognitive function, better metabolic health, and enhanced cardiovascular function.
Now, if you have spent time listening to the low carb crowd, you may have heard that this is because low carb diets reduce the secretion of insulin. While I won’t go into the topic here, I can say with certainty that this has nothing to do with it.
What I can say is that often when people go low carb, they also reduce calories. This leads to weight loss, and improvements in health.
But this isn’t magic.
This improvement in health occurs because of the weight loss – not specifically because of going low carb.
Anyway, enough of that.
What about exercise.
Low carb bodybuilding: are low carb diets good for muscle growth?
A key driver for muscle growth is training volume.
Broadly speaking, the more repetitions you perform with a given weight, the more muscle growth you stimulate.
While there is likely a tipping point where more volume will not be beneficial, I don’t think too many people are there. Which means that slight increases in volume is a probably a good thing.
Carbohydrates are your primary source of fuel during high intensity exercise (like weight training). They are stored in your muscle tissue as glycogen, and then broken down rapidly when you need energy.
When these stores are full, you have easy access to energy. Conversely, if they are not, your ability to access energy is limited.
With this in mind, even modest reductions in muscle glycogen have been shown to reduce gym performance.
This means that if you enter a workout in a glycogen depleted state (from eating insufficient carbohydrates), the number of repetitions you perform per set will be impacted negatively.
Over causes a reduction in training volume, which over time, may lead to inferior muscle growth.
It is for this reason that ketogenic diets have been shown to cause less muscle growth than calorie matched diets that include modest amounts of carbs.
Now, this isn’t to say that you cannot build muscle on a low carb diet, because you can.
But the amount you build may be less than if you were eating a higher carbohydrate diet.
Low carb strength training: are low carb diets good for strength?
Interestingly, while eating low carb impairs resistance training volume, this doesn’t impact strength.
In short, if you enter the gym after eating zero carbs, your absolute strength (i.e., the maximum amount you can lift for a single rep) will be about the same as normal.
Which is why eating low carb is unlikely to impact your strength gains over a short-term training program.
This is likely because, unlike muscle growth, gaining strength is not strongly associated with training volume. Which means that if you can get in 2-4 hard sets in per session, it will be enough to stimulate strength.
You may have noticed I said short term strength gains above.
This was deliberate.
Although short term gains in strength are mostly driven by lifting heavy, one of the most important factors for long term strength development is having bigger muscles.
In essence, a bigger muscle is a stronger muscle.
If you want to increase your strength gains in the long run, you will need to spend periods of time gaining muscle. If you don’t, it is likely that your potential gain strength will hit a ceiling.
All of which is to say that in the long term, eating higher carbohydrates may help you build more muscle, which will eventually lead to greater strength gains.
How much carbohydrates should I eat to gain muscle?
You might be wondering how much carbohydrate you should consume if you want to gain muscle – and we have got you sorted.
A recent review article provided clear recommendations with respect to diet and maximising muscle growth. While it was written with bodybuilders in mind, these recommendations are transferable to anyone looking to build muscle.
These recommendations are:
- Eat in a surplus of 10-20% maintenance calories (you can calculate maintenance calories here)
- Aim for 1.6–2.2 grams of protein per kilogram of bodyweight, per day (read more about how much protein to gain muscle HERE).
- Eat 0.5–1 .5 grams of fat per kilogram of bodyweight, per day.
- All your remaining calories should come from carbohydrates, which should be ~3–6 grams of carbohydrates per kilogram of bodyweight, per day.
Tick these boxes and you can be confident you are eating enough to maximise muscle growth.
Low carb bodybuilding: the take home message
If your goal is to get big and strong, then carbohydrates are your friend. Eat enough to ensure your gym performance remains high, and you will be good to go.
Eat too little, and you will leave gains on the table.
Seems like a no-brainer to me.
And if you want to read more about maximising muscle growth from a training perspective, make sure to read THIS article.