If I do sport on a calorie deficit how does my body recover?

If you're still active and training, along with losing weight, you're probably just seeing the benefit of retaining most of your muscle but having less mass to move. If your training is too intense, being in a deficit might slow your recovery, but usually only if your deficit is still somewhat aggressive.

And I personally think you get used to the new energy levels of being in deficit, and don't "miss" the extra energy. But for me sometimes just a day or two of eating at maintenance calories puts me back in personal best form for cardio and such... the extra calories are noticed fairly easily in extra energy.

In addition to what other smart folks said, this is where macros come in.

Macros aren’t directly relevant for weight loss, but they are relevant for health. When you are building muscle, the specific process involves creating tiny tears in your muscle that your body repairs. It is the repair process that makes your muscles stronger. When you eat protein, your body breaks the protein into its component amino acids, then uses those amino acids to repair your muscles. This is why it’s important to get enough protein even in a deficit.

Another thing you may mean by getting energy for your workouts is glycogen. If you’re working out for two hours at a time, you’re depleting the body’s stores of glycogen (which provides quick energy), and the body uses carbs from your food tor replenish it. As long as you’re getting proper nutrition, your body should be able to replenish its glycogen after each workout.

Finally, the other place energy is coming from is your fat stores. If you are eating at a moderate, reasonable deficit, then by definition you are putting less fuel into your body than it needs. The body makes up the difference by breaking down stored fat for energy.

Again assuming your deficit is not too aggressive and you are getting proper nutrition, you shouldn’t expect to be tired while in a deficit. However, your athletic performance might not be as strong as it would be if you were eating at maintenance. Depending on your macros, for example, you might have fewer carbs available for quick energy.

I think there’s also something to be said for adrenaline and the psychological effects of exercise. Both of those can make people feel more energetic, as can just having less weight to move during your activity.

Finally, it’s a little concerning that you describe your weight loss as rapid. How rapidly are you losing, and what’s your height and current weight? You sound like you don’t have a lot left to lose, so your weight loss shouldn’t be rapid at this point. That could mean your deficit is overly aggressive, which would put you at risk for getting inadequate recovery nutrition.

Everybody has given you some great answers. I was going to say dinner if what's already been said, but don't need to.

I'll just add that as your body adapts to exercise, one thing that happens is you get better at "producing" energy. Your mitochondrial density goes up, your blood has more plasma to transport more oxygen, etc.

There's a balance, exercise can be exhausting and fatiguing. But it sounds like this is something you've done for a long time, and probably built up to. If you'd just started doing 2 hard hours out of the blue, it would take more energy than your body can cope with.

Danp wrote: »

You're car analogy isn't quite right. You have 2 tanks, one of them is a spare tank.

In this situation the car (you) has a spare gas tank (fat) which is magic. Each day you add fuel (food) to the main gas tank (body) to use throughout the day. If you put more fuel in the main gas tank than you use that day, it takes the unused fuel and stores it in the spare tank. On the other hand if you put less fuel than you need into your main tank than you use during the day it then starts to take the extra fuel that has been stored in the spare tank and uses that.

So, if each day you put in just a little bit less fuel into your main tank all the extra fuel stored in the spare tank will slowly go down (you'll lose fat).

Thanks for that.