Replenish fluids and salts after exercise
When you exercise, sweating causes you to lose important body salts, like sodium and potassium, which need to be replaced. Many advanced athletes get in the habit of weighing themselves before and after exercise, in order to figure out how much fluid needs to be replaced. For each pound that you lose during activity, you should drink about 2-3 cups of liquid (or about one litre of fluid per kilo of weight loss).
What to drink after exercise
Water is fine as a fluid replacement. Since you’ll be eating afterwards, you’ll need to pick up carbohydrate, sodium (and likely some potassium) from your foods. For those who don’t normally drink high-kilojoule liquids, this is the one time they might drink fruit juices. They provide fluid and carbohydrate and—depending on the fruit—potassium, too. Sports drinks are great since they provide not only fluid and carbs (some even have a bit of protein, which your body also needs), as well as the right balance of salts that have been lost through perspiration. And they usually have a mildly light, sweet taste that encourages you to drink more.
Your body needs carbohydrates after you exercise
After your workout—especially if it’s really vigorous—your body has burned through a lot of carbohydrates: Carbohydrates contribute to the recovery of normal muscle function (contraction) after highly intensive and/or long-lasting physical exercise leading to muscle fatigue and the depletion of glycogen stores in skeletal muscle and it’s important to refuel as soon as you can. The recommended amount is about 1.0-1.2 grams of carbohydrates per kilogram of body weight per hour, after intense exercise. That’s about 75-90 grams of carbohydrates for someone weighing 75 kg. However, similar results are shown for lower amounts of carbohydrates equivalent to 0.8 grams of carbohydrates per kilogram of body weight per hour, equating to 60 grams for an individual weighing 75 kg, when consumed with protein (10-30 grams). Healthy carbohydrates—fruits, whole grains and the natural carbs in dairy products—are a good place to start with post-workout snacking.
Your body needs protein after your workout
Protein contributes to a growth and maintenance in muscle mass. It doesn’t take much—about 10 grams of protein or so will do. The ideal post-exercise meal or snack contains a combination of healthy carbs and protein. This is why athletes often turn to foods like a sandwich on whole grain bread, a dish of yogurt and fruit, a protein shake made with milk and fruit, or specially formulated recovery beverages.
Meal timing is important after exercise
When you exercise, your muscles become very sensitive to the nutrients that are available. And that sensitivity lasts for a limited amount of time. That’s why many athletes who want to optimize muscle recovery pay attention to this “metabolic window.” That’s a time period of about 30-45 minutes after exercise, during which you should try to eat your carbs and protein. During this critical time after you exercise, your muscle cells are more sensitive to the effects of insulin, a hormone that helps transport amino acids (from protein) into your cells. Insulin also works to drive carbohydrate into the cells, where it is stored in the form of glycogen. Carbohydrates contribute to the recovery of normal muscle function (contraction) after highly intensive and/or long-lasting physical exercise leading to muscle fatigue and the depletion of glycogen stores in skeletal muscle. Once you kick this fuel storage process into gear, you can keep it going for up to eight hours if you continue to provide your body with a shot of carbohydrate every two hours.
Beck et al, Open Access J Sports Med. 2015 Aug 11;6:259-67
Kerksick et al. Journal of the International Society of Sports Nutrition (2017) 14:33
Jäger et al. Journal of the International Society of Sports Nutrition (2017) 14:20
Susan Bowerman is Director of Nutrition Training at Herbalife. Susan is a Registered Dietitian and a Board-Certified Specialist in Sports Dietetics