Nutrition and training go hand in hand. The proper fueling plan not only supports the body during a workout, but aids in its recovery afterwards. Did you know that skipping a meal or post training snack stalls recovery, downregulates metabolism and enhances the body’s fat storage? The hard work put in during workouts, must be supported through recovery.
During exercise, your body uses glycogen (the storage form of carbohydrates) from your muscles and liver as fuel. Your body can store anywhere from 1,400 to 2,000 calories of glycogen, which is enough for about 90 minutes of endurance exercise. Therefore, athletes should fuel with carbohydrates during workouts lasting longer than 90 minutes for optimal performance.
Ok, so now the workout is over. Now what?
Our Post Workout Physiology
Regardless of the duration or intensity of a workout, athletes should replenish their bodies following exertion of any kind. There are many processes occurring simultaneously within the body, so let’s break down what is happening and why fueling for recovery is so important.
Energy stores are empty. The muscles are fatigued and have been depleted of its energy stores. The body immediately turns to its food sources to replenish what was lost. A mix of 2 to 3 grams of carbohydrates to 1 gram of protein is best here.
Insulin levels are peaking. Insulin is a hormone responsible for regulating carbohydrate and fat metabolism. As insulin is released, glucose is absorbed into the bloodstream and skeletal muscle tissues in the storage form of glycogen, or fat stored in adipose tissue, and transformed into energy. This process transports nutrients throughout the body.
When exercise starts, insulin is suppressed to allow the glucose to be used as fuel during the training session. At this point, it is best to limit those sugar-ridden sports beverages for workouts lasting less than 60 minutes, especially if your goal is to improve body composition. Immediately following a workout, insulin levels begin to peak again, meaning nutrients from food will move quickly and efficiently to your muscles. This is where the refueling window of 30 to 45 minutes comes from to replenish glycogen stores and promote muscle protein synthesis (aka muscle growth).
Hormones begin to rebalance. During training, cortisol naturally increases in our body to support an increase in energy metabolism. Cortisol regulates blood sugar by aiding in fat and protein metabolism to create glucose to fuel training sessions. Note, entering a training session not yet fully recovered from a previous workout, and/or engaging in a session lasting longer than 90 minutes, can increase the risk of breaking down muscle for fuel. You can avoid this by fueling throughout training sessions and supplying your body with 30 to 90 grams of carbs per hour (with sessions lasting longer than 90 minutes).
As glycogen stores are replenished by carbohydrates in the form of glucose, the body will more quickly regulate its hormonal imbalances.
Muscles begin to rebuild. Protein synthesis (aka muscle gains) begin as soon as the body has a readily available source of protein in the form of amino acids. The body needs all nine essential amino acids in order to begin rebuilding and restoring muscle tissue: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. While each is integral in restoring and building muscle tissue, the most important amino acid is leucine because it kickstarts the process.
One should try to consume protein at all meals and snacks throughout the day. Aim for 20 to 40 grams of protein post training sessions to adequately supply your muscles with the fuel they need for repairing and building. The more quickly the body is supplied with these essential amino acids, the faster it can rebuild and restore muscle tissue.