Which energy system is primarily used during high-intensity, short-duration activities?

The ATP-CP system, also known as the phosphagen system, is the primary energy system used during high-intensity, short-duration activities. This system relies on the immediate availability of adenosine triphosphate (ATP) and creatine phosphate (CP) stored in the muscles. During activities such as sprinting, weightlifting, or high-intensity interval training, the body utilizes this system to produce energy quickly for explosive efforts.

Due to the limited stores of ATP and CP, this system can sustain maximum effort for about 10 seconds before fatigue sets in. As a result, it is ideal for activities that require rapid bursts of energy but are not sustained over longer periods. This is why short, intense activities like a 100-meter dash or a single rep of a heavy lift predominantly rely on the ATP-CP system for energy production.

Other energy systems, such as the aerobic system and the lactic acid system, are activated more in prolonged activities or those that can sustain moderate intensity over a longer duration. The fat oxidation system is primarily used for low-intensity, long-duration activities, using fat as a fuel source, which isn't suitable for high-intensity efforts. Hence, the ATP-CP system stands out as the key