Common sense says a hard workout should leave you feeling famished. After all, you just burned a ton of calories, right? But ask anyone who has ever crossed the finish line of a marathon or survived a brutal boot camp, and you'll be surprised at how often it's the exact opposite.
The Science of Hunger and Workouts
In fact, a small pilot study published in the March 2017 issue of the Journal of Endocrinology confirms what many experienced exercisers already know: Exercise can suppress appetite, especially when that exercise is intense (at or above 75 percent of a subject's peak oxygen uptake) or long (90 minutes or more).
Why? According to Alissa Rumsey, RD, owner of Alissa Rumsey Nutrition and Wellness in New York City, intense or long workouts causes levels of ghrelin (also known as the "hunger hormone") to drop, and it may take two to three hours for levels to return to normal after your workout.
However, research shows that exercise type also influences appetite suppression, though the exact mechanisms behind this effect are unknown. One American Journal of Physiology study from 2009 found that, while a 90-minute strength training session suppressed ghrelin levels in men, only aerobic exercise — in this instance, a 60-minute run — had the ability to both lower ghrelin and increase levels of peptide YY, an appetite-suppressing gut hormone.
That said, there are plenty of reasons you might actually be ready to eat before you've even finished your cooldown. If, for example, your workout was more laid-back, you may not feel the appetite-suppressing effects of exercise to the same extent as someone who just braved a traditional CrossFit workout.
Time of day can also impact whether or not you're hungry after a workout. Many morning exercisers, for example, replenish with breakfast. Finished your workout at dinner? Don't be surprised if you have food on the brain, especially if you haven't eaten anything since lunch, says Albert Matheny, RD, co-founder of SoHo Strength Lab and adviser to Promix Nutrition.
The Important of Refueling After Your Workouts
Regardless of whether you're hungry or not, it's important to have a post-workout meal plan. In order to jump-start the recovery process, it's critical to eat something within 30 to 60 minutes of finishing your workout.
According to Heidi Skolnik, CDN, owner of Nutrition Conditioning, Inc., the window immediately following your workout is the time when your body is most receptive to both muscle repair and glycogen replenishment. (Glycogen is the carbohydrate our bodies store to use for quick energy.) If you skimp on recovery, your next workout could be compromised by muscle soreness and lack of energy.
But don't think you need to sit down to a full meal as soon as you've kicked off your workout shoes; all you really need is a snack to give you a quick shot of muscle-repairing protein and energy-restoring carbohydrates.
"Having a little recovery snack can help take the edge off your hunger so that by the time you've showered, changed and cooked a meal, your appetite return doesn't hit so big that you can't make a sane decision and you end up eating everything," Skolnik says.
Perfect Post-Workout Snacks
According to Keri Gans, RDN, owner of Keri Gans Nutrition and author of "The Small Change Diet," you'll want a snack with at least 10 grams of protein and 15 to 30 grams of a nutrient-rich carbohydrate like oatmeal. "Carbs are our body's main source of fuel," she says, "so you don't want to skimp on it when doing any kind of exercise routine."
If you know you won't be able to stomach solid foods after your workout, plan to fuel up with liquid calories. Downing a post-workout smoothie, for example, is a quick and easy way to get a healthy dose of protein and carbs. According to Rumsey, adding pulses like chickpeas and white beans to your smoothie will provide plant-based protein as well as carbs, fiber and potassium.
Try blending a large banana, a half-cup of chickpeas, one tablespoon of peanut butter, a dash of cinnamon and a cup of milk or unsweetened nondairy milk for a post-workout meal that's loaded with a good balance of protein, carbs and fiber.
Another great option for people who have trouble with solids right after their workout is to have a glass of 100 percent pomegranate juice like POM Wonderful, says Rumsey. One eight-ounce serving provides 600 milligrams of potassium, 38 grams of carbs and a dose of polyphenols, a micronutrient available through plant-based foods that have been shown to help with muscle recovery.
A 2015 study in Food & Nutrition Research reveals that men who ingested a high-dose blend of polyphenols (2,000 milligrams per day) for 12 weeks reported decreased muscle soreness 48 hours following a downhill run and strength test, while men who ingested a low-dose blend (1,000 milligrams per day) or a placebo reported no difference.
Note: Juice is often high in sugar, but, according to Rumsey, the natural sugar is a great source of carbohydrates to help replenish your body after a workout. "Your muscles are looking to take up carbohydrates within a few hours post-workout, so this is a great time to drink juice," she says. So just make sure the juice you drink has no added processed sugar.
Pair the juice with a protein-based snack, such as six ounces of Greek yogurt, two hard-boiled eggs, one to two ounces of beef jerky or a half-cup of cottage cheese.
What Do YOU Think?
Do you feel like you're never hungry after working out? Or are you always hungry after working out? Do you prefer a snack before or after your workout? What's your go-to workout snack? Share your thoughts and questions in the comments below!