Cardio Does Not Burn Fat!
Ask people in the gym, why they’re doing cardio and you’ll get a range of answers.
Some of them will say “to burn fat”.
Depending on what else they’re doing, they might be completely wasting their time.
Cardio does not burn fat. This is a common misconception.
In fact, there is nothing you can do to burn fat other than to be in a calorie deficit.
Cardio burns calories, not fat
Cardio does not burn fat directly.
It just burns calories.
Doing cardio only makes a difference if it’s the thing that’s putting you into a calorie deficit by increasing your maintenance (more calories burned through activity = higher maintenance). It will also speed up fat loss if you use it to make your calorie deficit bigger.
You can do hours and hours of cardio and lose ZERO weight if you still eat enough calories to ensure that you’re not in a deficit.
It’s also possible to lose any amount of weight without doing any cardio. You just eat fewer calories than your maintenance. This is my approach (I hate cardio). I could lose weight faster if I did some more cardio, but I don’t need to.
Cardio to “burn fat” makes no sense if you’re trying to gain muscle
Many of the people doing cardio to burn fat are doing it to burn fat while also pursuing a goal of building muscle.
They do their cardio “to burn fat” at the end of their weights session, or on days where they don’t lift.
They’re lifting weights, with the aim of building muscle. They’re then going and doing cardio, with the aim of burning fat.
You can’t focus on both at the same time.
If you want to build muscle, you need to be in a calorie surplus.
Going and doing cardio to “burn fat” after lifting weights to build muscle makes no sense. It will not work.
The best case scenario is that ONE of the things you’re doing is a waste of time. The worst case scenario is that all of what you’re doing is a waste of time.
Let’s look at the best case first
Let’s say you’re in a calorie surplus of about 800 calories per day before the cardio.
You do your cardio and burn an extra 500 calories a day. Your calorie surplus is now 300 calories per day.
This is a good amount. You will continue to build muscle, and you will also stay quite lean. 300 calories is quite a small surplus (although it depends on what your maintenance is).
You won’t lose any fat though, even though you’re doing cardio for this reason. You are just burning additional calories and eating away at the surplus you were in. All you are doing is slowing down the rate of weight gain.
The other thing you could end up doing is putting yourself into a calorie deficit with your cardio. Let’s say your surplus was 300 calories before the cardio. You then burn another 500 calories per day and end up in a deficit of 200 calories because of the cardio.
You will now not gain any muscle, but you will be losing fat at a slow rate of about a kilogram every 5 weeks.
Either way, one of your pursuits is going to be a waste of time if you’re trying to build muscle but you’re also doing cardio to burn fat!
Now let’s look at the worst case scenario:
The worst case scenario is that you end up at maintenance!
Imagine you are eating in a 500 calorie surplus before the cardio. Your cardio then burns 500 calories per day. You end up neither in a surplus or a deficit.
You won’t gain any muscle and you won’t lose any fat!
You’ll stay the same for as long as you do this!
What a waste of time!
What You Should Do Instead
Realise that cardio doesn’t burn fat.
Only a calorie deficit burns fat.
Cardio is a tool you can use to get yourself into a calorie deficit, or increase the size of it.
Don’t try to focus on fat loss and building muscle at the same time.
The best approach is to get lean first before you attempt to build muscle.
During the process of getting lean, just focus on maintaining the muscle you already have while losing fat. Lift heavy and eat lots of protein whilst staying in a calorie deficit that isn’t reckless.
Once you’re lean, you’ll be in a better position from which to begin your muscle building phase.
Unfortunately, you are GOING TO ADD FAT as you gain muscle. For most people, about the best you can hope for is muscle gain and fat gain happening at an equal rate (i.e. in a 1:1 ratio).
The amount of fat you add will depend on the size of your calorie surplus. The bigger the calorie surplus, the more fat you will add. I’ve written about this extensively.
The reason you want to get lean before attempting to gain muscle is this
Nutrient partitioning is better when you’re lean vs. when you have higher bodyfat levels. This means your body is basically more likely to store extra calories as fat when you have more bodyfat. When you’re leaner, you’re better at building muscle in a surplus.
The other reason you want to start as lean as possible is it gives you a longer timeframe within which to keep bulking. Bulks are best when they’re eked out slowly over a long period of time, like a year.
Don’t rush it! You can’t gain any more muscle by simply eating more. Having a 1,000 calorie surplus is only going to get you fat faster, and mean you have to stop bulking, stop gaining muscle, and focus on fat loss again.
The Last Word: Your Key Takeaway
Understand that doing cardio whilst attempting to gain muscle isn’t going to burn the fat as you add it, or prevent you adding it in the first place.
Fat gain happens while building muscle. If you want to build muscle, there’s no avoiding it. Cardio won’t stop it.
The bigger your surplus, the more fat you will gain.
You CAN use cardio to bring the size of your surplus down to a more sensible amount. This is a risky game, however. How do you REALLY know how many calories your cardio is burning? What if you end up at maintenance, or in a deficit? Then you won’t build any muscle at all.
Why not just track what you eat, find the small surplus that sees you gain rate slowly (minimising fat gain) and then don’t do any extra cardio?