Aerobic Exercise Performance
Aerobic exercise includes activities such as low-to-moderate-intensity running, cycling, and swimming. These exercises are described as aerobic because they are fueled by aerobic metabolism, which means oxygen is used to make energy. The capacity to deliver oxygen to muscles via the cardiorespiratory system (the lungs, heart, and blood vessels) and the ability to produce energy (adenosine triphosphate, or ATP) using oxygen are important components of aerobic exercise performance.
While aerobic exercise performance determines success in endurance sports, it is also an important aspect of other sports that include an endurance component (e.g., soccer and basketball) and is closely tied to cardiovascular health.
Aerobic exercise performance is measured by how long it takes someone to complete an event of a specific distance (i.e., a “time trial”), with a faster time indicating better performance.
Other measures of aerobic fitness that may predict aerobic exercise performance include aerobic capacity, lactate threshold, and exercise efficiency/economy (i.e., the oxygen cost of movement). Aerobic capacity, or VO2max, is the highest rate of oxygen consumption that the body can achieve. VO2max is the most commonly measured component of aerobic fitness and is a key predictor of aerobic exercise performance — elite endurance athletes have VO2max values 50%–100% higher than non-elite active people. VO2max, lactate threshold, and exercise efficiency are all measured, or estimated, using specific exercise testing protocols.
Low-intensity, high-volume training (<80% of maximal heart rate), threshold/tempo training (80–95% of maximal heart rate), and high-intensity interval training (HIIT) (>95% of maximal heart rate) can all improve aerobic exercise performance when performed 20–60 minutes per day, 3–5 times per week, for around 2–6 months. A well-designed training program may incorporate all types of training to attain peak performance, with some data suggesting a ratio of 80% low-intensity training and 20% high-intensity training is optimal.
Among the supplements and ergogenic aids showing the most promise for improving aerobic exercise performance are caffeine, supplemental carbohydrates, creatine (creatine monohydrate), nitrate (e.g., beetroot juice), beta-alanine, and sodium bicarbonate. Other supplements with less robust evidence to support their efficacy are citrulline, glycerol, quercetin, taurine, arginine, and medium-chain triglycerides (MCTs).
Aerobic exercise performance is enhanced by strategies that maintain high carbohydrate availability. Because glycogen depletion is associated with fatigue and reduced work rates, sports nutrition guidelines recommend a higher-carbohydrate diet. However, the number of carbohydrates consumed should depend on the volume and intensity of exercise. For light to moderate exercise performed for up to 60 minutes per day, 3–7 grams of carbohydrate per kilogram of body weight per day (g/kg/d) is recommended, while individuals performing higher-intensity exercise for longer durations (1 to 5 hours per day) should consume 6–12 g/kg/d. It’s also important to ensure an adequate intake of energy, carbohydrates, protein, fat, vitamins, and minerals.
Adequate rest and muscle recovery are crucial for aerobic exercise performance. One of the main factors influencing recovery is sleep, a lack of which has been shown to impair physical and mental recovery from exercise. Other factors that can positively influence recovery include nutrient timing and choice of foods, limiting alcohol exposure, avoiding overtraining,, and reducing emotional and psychological stress and fatigue.
The environment can also influence aerobic exercise performance; heat and cold, humidity, air temperature, wind speed, altitude, and even clothing are all factors to consider when exercising in extreme conditions.