What you eat after cardio and after a weight training workouts are not always one in the same. Weight training is geared towards muscle gain, while cardio is mostly used for fat loss.
What You Eat Depends on Your Goals
When we weight train, we start depleting our muscles of glycogen, and we break down muscle tissue. Our goal is to make it grow back bigger and stronger. We eat carbohydrates and protein post workout so that we can replenish muscle glycogen stores (energy) and start rebuilding muscle.
On the other hand, when we do cardio, our goal is usually to burn extra calories and lose fat. This means what we eat will be different than after a typical weight lifting session. You could certainly eat the same thing either way. However, if you’re already at a low body fat and you’re looking to eek out that last bit of fat, you’ll want different nutrition after a cardio session.
What Should You Eat After Cardio?
During a typical cardio session, your body’s biochemistry undergoes some changes. Your body suppresses insulin production and starts releasing other hormones like growth hormone (GH) and testosterone. Not only that, but your body releases several neurotransmitters like adrenaline, epinephrine, serotonin, dopamine, and endorphins. The first two assist with fat mobilization, while the last three are feel good chemicals (think runner’s high).
What we want to do after cardio is:
- Keep insulin production suppressed. Insulin is a fat storage hormone which is not conducive to fat loss.
- Keep growth hormone (GH) levels elevated. GH is catabolic to fat cells. It is one of, if not the most powerful hormone for losing fat.
- Keep those fat loss neurotransmitters flowing so that fat loss continues.
How Do We Accomplish These Goals?
It’s quite simple actually. You control your carbohydrate intake. Eating too many of or the wrong type of carbohydrates will immediately throw you out of fat burning mode. After your workout, your insulin sensitivity is at its highest. This is great. It means you’ll be able to be a bit more loose with your carbohydrate intake.
What you don’t want to do however, is spike your insulin levels. Doing so will halt all fat burning, and will drop your growth hormone levels, along with any other fat loss benefit you just created from your cardio.
If you are in pure fat loss mode, it would be beneficial to have a low carb or carb-less meal after cardio. Something along the lines of a protein shake with some essential fatty acids (EFAs), such as whey protein isolate (if you use protein powder) mixed with fish/flax oil, or a chicken salad with veggies will keep the fat burning machine churning, while at the same time provide protein and essential fats to start rebuilding muscle. You can also have any number of lean protein/healthy fat/veggie meals after cardio.
Will you be replenishing muscle glycogen with this meal? No, not really. Some of the protein may be converted into glucose through a process called gluconeogenesis, but even if this did happen, it would have a minimal effect on insulin levels – meaning you will continue to burn fat. Plus, it’s unlikely that you completely depleted glycogen stores, so you will still have plenty of energy for your next strength training workout.
To sum up, if you want to keep fat burning going for as long as possible, you’ll want to manage your carbohydrate intake after cardio. You don’t have to go no-carb. Having a small serving of low-glycemic carbohydrates is perfectly fine.
I want to emphasize that dropping your carb intake after cardio is an advanced fat loss strategy that is most useful as your body fat gets lower. It’s also best suited for people that separate their strength training and cardiovascular training into separate workouts. The important thing, as always, is to make sure you’re actually doing cardiovascular training. Once you’re consistent with your workouts, then you can start focusing on the finer details.