Many athletes look to dietary supplements to enhance performance and recovery. Here’s a quick rundown of some of the most popular supplements.
Branched-chain amino acids (BCAAs)
During prolonged endurance exercise, when glycogen stores are low, BCAAs are the only amino acids that skeletal muscles can use for energy, so they may be helpful in reducing fatigue during exercise. BCAAs also help drive sugar from the bloodstream into muscles, so it can be used for energy. When used both before and after exercise, BCAAs support muscle repair and growth.
Taken after resistance exercise, milk-based proteins are effective in increasing muscle strength and are also associated with favorable changes in body composition. Milk contains two major proteins: whey and casein. Both proteins are rich sources of branched-chain amino acids and are particularly good sources of the amino acid leucine, which pays a key role in muscle recovery. Whey protein is absorbed rapidly by the body, and so it can quickly transport amino acids to tissues in order to stimulate muscle recovery and growth. Casein is more slowly digested than whey, and many athletes supplement with casein protein at bedtime to help with muscle recovery while they sleep.
Creatine is an amino acid that is naturally found in animal proteins such as meat and seafood. It’s stored in the muscles where it’s used to produce energy as part of a compound called phosphocreatine (PCr). The PCr energy system is called into play when performing short bursts of intense activity, so creatine supplements are used primarily by strength athletes to help support intense muscle contraction and, therefore, muscle strength. Even though there are dietary sources, many athletes use supplementary creatine to boost muscle stores. Vegetarians and vegans may have a better response than omnivores, since their baseline creatine stores may be lower.
Arginine is involved in the synthesis of Nitric Oxide which dilates blood vessels and increases blood flow. As a result, arginine helps promote healthy blood flow and delivery nutrients to muscles during exercise.
Electrolytes are particular minerals that play a vital role in helping the body to maintain fluid balance. Some of the most important ones that athletes need to consider are sodium, potassium and magnesium. During sweating, electrolyte losses can occur and, if they aren’t adequately replaced, performance may be impaired. This is why it is so important to pay particular attention to electrolyte intake during intensive exercise (especially in the heat), as well as to replenish afterward, to replace these important salts that are lost. Many sports beverages are specifically designed to not only replace fluids that are lost through sweating, but also key electrolytes, which also enhance fluid absorption.
Carbohydrates are a key fuel for your brain and muscles. For athletes engaged in prolonged, sustained activity, it’s particularly important to have plenty of carbohydrates available both in the muscles and the bloodstream. It’s important to consume adequate carbohydrates prior to engaging in strenuous activity to top off fuel reserves – this will help ensure that there is an adequate energy supply to fuel working muscles. For those engaging in sustained, high-intensity exercise, carbohydrates need to be supplied during exercise, in the range of 30 to 60 grams per hour to ensure that enough fuel is available. For recovery, carbohydrates are important to help replenish muscle carbohydrate stores, which prepare the athlete for the next bout of exercise. Specially designed beverages and other products are formulated to support these needs.
Caffeine is a central nervous system stimulant and it facilitates the body’s ability to use fat for fuel. For this reason, caffeine may help to extend endurance during strenuous exercise. Because of its stimulating effects, it also reduces perception of fatigue and may help to optimize sustained activity.
Heavy exercise increases oxygen consumption, which promotes oxidative stress in the body and can damage cell membranes. Antioxidant nutrients help reduce oxidant stress. In order to boost the body’s natural antioxidant defense system, antioxidant nutrients such as Vitamins C and E can be beneficial.
Susan Bowerman, MS, RD, CSSD, CSOWM, FAND Senior Director, Worldwide Nutrition Education and Training.