The power source of muscle cells is known as adenosine triphosphate (ATP). It fuels all the movements, whether quick sprints or prolonged activities. During exercise, ATP gets depleted faster than it can be produced, so producing it in an efficient way is necessary in order to have sufficient.
In long-distance events, ATP assists with both short, intense bursts of effort and longer, less intense effort. The ATP-PC system provides immediate energy for 10–15 seconds through the breakdown of muscle phosphocreatine. Then ATP is produced continuously through various mechanisms: anaerobic glycolysis supplies energy for moderate effort for 2 minutes, while aerobic respiration in the mitochondria utilizes oxygen with carbs and fats to produce ATP for hours. During training, the body adds more mitochondria, blood vessel networks, and enzyme activities, enabling the body to make ATP faster as well as combat fatigue. Efficient ATP production enhances performance in all long-distance events as athletes can maintain their power, recover in between intense efforts, and cross the finish line strongly.
