Which of the following are the three energy systems used by the body during exercise?

The three energy systems used by the body during exercise are indeed the ATP-PC system (also known as the phosphagen system), anaerobic glycolysis, and the aerobic system.

The ATP-PC system is responsible for providing energy for short bursts of high-intensity activities, typically lasting around 10 seconds, using stored creatine phosphate in the muscles. This system operates without oxygen, making it anaerobic.

Anaerobic glycolysis kicks in for activities lasting from about 10 seconds to 2 minutes. It generates energy by breaking down glucose without the need for oxygen, resulting in the production of lactic acid as a byproduct.

The aerobic system supports longer-duration activities, typically over 2 minutes, and relies on oxygen to generate energy from carbohydrates and fats. This system provides sustained energy for endurance activities.

The other choices include terms that either incorrectly label the energy systems or combine elements of the systems in a way that does not accurately reflect the classification of energy production mechanisms in the body. Understanding these systems is crucial for developing tailored training programs based on the type of exercise and energy demands placed on the body.