As someone who has dabbled in intermittent fasting, one question that often comes up is whether it's "bad" for your body to skip eating after a workout — whether you might sabotage your goals of building muscle and losing weight. I usually work out in the morning, as early as 5:30 a.m., but my eating window often doesn't start until noon. It's one thing to wait an hour or so for a post-workout snack, but six?
Another issue: sometimes you just aren't hungry after a workout. In general, listening to your hunger cues will lead you in the right direction: toward a healthy weight and lifestyle. But I also constantly hear how important it is to refuel after exercise. So just how important is it to eat after your workout – and what do you do if you don't feel like eating?
What Happens If You Don't Eat After a Workout?
You may have heard something about what not eating after a workout can do to your body, but it's worth a quick refresher. During a workout, you're breaking down muscle, actually creating small micro-tears in the tissue. That breakdown process is what makes it possible to build your muscles and help them grow bigger and stronger, but only if you refuel correctly with nutrients like protein, which helps to repair that damage. Registered dietitian Michele Fumagalli, LDN, from the Northwestern Running Medicine Clinic, told POPSUGAR that failing to fuel after a workout can push your body into a catabolic state, where it's breaking down muscle mass — the opposite of what you want.
You'll also need to eat carbs, especially if your workout involved cardio. Your body uses glycogen — stored glucose — as energy to fuel your workouts, and it gets that glucose by converting carbohydrates. Rebuilding the supply gives you the energy to recover from your workout and keep going through your day.
How Long Can You Wait to Eat After a Workout?
When determining how soon you need to refuel after a workout, there are a few different factors you have to take into consideration. The first, Michele said, is how recently you've eaten before the workout.
For example, let's say you stop eating at 8 p.m., then wake up the next morning to do a 6:30 a.m. fasted workout — no food beforehand. After that workout, particularly if it involved strength work or high-intensity interval training (HIIT), is a crucial time for refueling, Michele said. If it's been several hours since you last ate, replenishing your body will prevent it from breaking down muscle mass, allowing it to start the repair and recovery process instead. This also applies if you have a short recovery window between workouts; if you're doing "two-a-days," for example, or working out at night and then early in the morning.
"The pre- and post-workout food align," Michele said. "Whatever you ate at lunch or even at breakfast is going to help you through your workout and post-workout." If you haven't eaten beforehand, it's crucial to refuel within an hour of working out. But if you had a meal two hours before your workout, Michele explained, "you can probably wait an hour or two to eat your next meal."
Regardless of your pre-workout food, Michele said it's usually fine to wait 30-45 minutes to eat after a workout. What you don't want to wait on is hydration. "We need to make sure we're drinking a lot of fluids, primarily water or water with electrolytes," Michele said. The electrolytes are especially important for cardio workouts, according to registered dietitian Kristin Kirkpatrick of the Cleveland Clinic's Wellness Institute, and particularly when your workout was longer than an hour.
Should I Eat Even If I'm Not Hungry?
With all of that in mind, Michele said that it's crucial to eat within at least two hours of a workout – regardless of whether you're hungry or not. And, yes, that includes those of us doing intermittent fasting. That doesn't mean you have to break your fast early every day, though you may want to if you're not scheduled to eat for more than two hours after exercise. If you want to stick to your fasting schedule, it'll be about structuring your eating and workouts so that you're able to refuel within that two-hour window.
Kristin added that if you're doing 5:2 intermittent fasting (eating regularly five days a week and restricting to 500 to 600 calories for the other two days), you may want to avoid working out at all on your fasting days. "The whole purpose of time-restricted eating is to limit your consumption to no more than 8-10 hours," Kristin told POPSUGAR. "You really have to plan to set your workout and fueling needs around that."
If you're simply not hungry after a workout, Michele still recommended eating at least some protein and carbs. It's not necessarily that your body doesn't want the food; she said you might not be hungry post-exercise simply because "your body isn't used to getting food right after your workout. You might just get accustomed to that routine." And it's not a routine that will help you reach your fitness and weight-loss goals.
Foods to Eat After a Workout
It's best if you can eat a full meal within two hours of exercise, Michele said, complete with protein, carbs, and vegetables; but that's not always possible, and might not even sound good if you're not typically hungry after working out. In that case, Michele said a protein shake can be a good option. "They're great for convenience," she explained, if you know you're not going to be able to sit down for a meal for a few hours, or if you just don't feel like eating a full meal. Make sure to eat a piece of fruit, such as a banana, on the side or throw it in the smoothie itself. Many packaged protein smoothies don't have any carbs, Michele said, but they're essential for recovery as well.
If you're going straight from the gym to the kitchen, though, there's no need to push the extra protein; just make sure you have a good source of it in your meal, as well as carbs and vegetables. If you're looking to increase your strength and avoid muscle breakdown, Kristin recommended protein-rich foods like:
- Whey protein
After intense cardio workouts, it's especially important to replenish your supply of glycogen by eating carbs. Kristin and Michele recommended:
- Low glycemic index (GI) fruits like apples, pears, berries, or cherries
- Full-fat yoghurt
- Nut butters
Be careful of your portion sizes as well. "The key is to know how much you actually need," Kristin said. "Chances are, unless you are training or running a marathon, you need to eat less than you think." Here's a handy" guide to determining how big your portions should actually be.
And remember that your post-workout fuel, while important, is only a small part of your everyday diet. "Just a pre- or post-workout meal isn't going to help you as much as if you're consistently eating healthy and balanced," Michele said. "This is just one meal out of three that you're eating. It's important to look at the bigger picture too."