Hormones, Muscles, and T Cells
Most of you know that you need some kind of recovery drink or snack after a hard workout. However, you may not know why it’s necessary and/or what to eat or drink.
To better understand the need for recovery nutrition, let’s take a look at three things that occur inside your body during vigorous exercise:
Hormones Gone Wild
During high intensity exercise, levels of cortisol, epinephrine, norepinephrine, and glucagon surge in a grand effort to supply energy to the working muscle. As blood glucose levels drop, these hormones work together to stimulate glucose production by the liver. Cortisol levels, in particular, stay elevated for 30 to 60 minutes after we stop exercising and continue to catabolize protein and carbs even though we no longer need them for energy. Consuming a recovery drink or snack during this period of time will lessen the degree of protein degradation and depletion of glycogen stores.
Fire in the Muscle
During a hard run or ride, our muscles utilize three “branched-chain amino acids” (BCAA’s) to off-set the protein degradation and damage that naturally occurs with hard exercise. These BCAA’s are broken down in the muscle cell and used to generate ATP, which unbeknownst to most people, continues after exercise stops. To keep your body from having to breakdown more protein to get BCAA’s, you need to take in some “exogenous” protein in the form of food or beverage (aka recovery snack). Taking BCAA's in supplement form is not as effective as getting them in food with "intact proteins".
Ever run a marathon and then gotten sick afterwards? That’s because all that running (or any kind of hard exercise) temporarily lowers immune function which increases your susceptibility to infections. This occurs because cortisol and epinephrine suppress type 1 T-cell cytokine production which is vital for a strong immune system. Lowered immune function has been reported in exercise that lasts longer than 1.5 hours that is performed without nutritional intake during and after the exercise bout.
Nutrition can have a big impact on our immune system. For instance, a low intake of macro-nutrients (fat, carbohydrate, protein) or a low intake of specific micronutrients (zinc, selenium, iron, copper) can lower our resistance to infection. Aequate intakes of vitamins A, C, E, and B-6; and folic acid, zinc, iron, and copper help strengthen our ability to fight off illness or infection. These nutrients are found in fruit, vegetables, whole grains, eggs, meat, legumes, nuts, and seeds.
So, what is a good recovery snack or beverage? Anything with a 4:1 ratio of carbs to protein from nutrient-dense foods (see below for examples). The carbs will replace the glycogen you just used up and the protein will lessen the need for BCAA’s and help promote muscle synthesis.
Cereal, milk, and fruit
Sandwich on whole grain bread with lean meat or peanut butter
Eggs and toast
Yogurt and fruit
Keep in mind that recovery nutrition is important only after hard workouts or on days when you will be doing two workouts separated by several hours. It's not as important after an easy run or casual bike ride. The excess calories coupled with lower intensity exercise can potentially lead to weight gain.
Eat up and recover well!