While my personal favorite post-workout meal is a veggie burger and a beer, I’m not doing my body any favors by indulging in that way. The moments immediately following a vigorous workout are just as important as the workout itself. Once you’ve stopped exercising and your heart rate has returned to normal, your body immediately begins working to replace the fluids and nutrients it lost during the effort. Most importantly, you’ll want to replenish the glycogen stores in your muscle tissue and encouraging protein synthesis for muscle repair. According to the American Council on Exercise, the best way to do this is by consuming a combination of carbohydrate and protein. Interestingly, these recommendations hold true whether you’ve just finished a long endurance workout, or an intense weight lifting session.
A good general guideline to follow is to consume around .5 grams of carbohydrate for every pound of body weight, along with 10-20 grams of protein. The timing of this post-workout snack is actually more important than it’s exact composition – you want to take in these nutrients within 30 minutes of stopping exercise. So think about bringing a portable snack with you to the gym. A banana and some nuts, half a peanut-butter sandwich, or a high-quality protein drink are all good options.
Note that if you’re trying to lose weight, then this post-exercise snack needs to be factored into your daily calorie allowance, and not consumed on top of it. For a person weighing 200 pounds, the formula above would result in a post-workout “snack” of around 500 calories! This leads me to my next point – many people won’t need to consume a post-workout snack at all.
Unless your aerobic workout lasted for at least 90 minutes or your intense weight lifting session involved a true hour of lifting, then your body’s glycogen stores probably weren’t depleted that much to begin with. Certainly there is no need to consume sports drinks for exercise lasting less than one hour. There may be some benefit to taking in a smaller amount of protein and carbohydrate following a shorter, but still intense workout, but be careful that you are truly only replenishing what was depleted, and not just adding unwanted calories. Even those who are looking to bulk up should heed this advice: If you’re already running at a calorie surplus for the day, then consuming more calories after a workout (no matter how high-quality they may be) will likely lead to a different kind of weight gain than you’re after.
Endurance athletes can definitely benefit from taking in some electrolytes both during and after a long workout (< 60 minutes at high intensity; < 90 minutes at moderate or lower intensity). But don't skip the protein, and try not to get all of your carbohydrates from that sports drink. Shoot for a mix of both simple and complex carbs, with a bit of fiber. Your body will use the fast-burning simple sugars right away to replenish those glycogen stores, but the slower, more complex carbs will help ensure that you don't collapse on the couch exhausted an hour after you've finished. Of course, if it was a really tough workout, you may end up doing that anyhow. I find myself doing it every now and then, often with a beer in my belly and a smile on my face.