Final answer:
A short duration of activity that precedes major exercise is a warm-up. It involves gradual increase in physical activity to prepare the body, including stretching, and is crucial for injury prevention.
Step-by-step explanation:
The short duration of activity that precedes major exercise is known as a warm-up. A warm-up is a critical part of preparing the body for strenuous activity, as it gradually increases the heart rate and blood flow to muscles, reducing the risk of injuries such as muscle strains. Some warm-ups may include stretching exercises to improve flexibility and prepare the body for movement. Warming up is also an essential component of a moderate exercise program and should be incorporated before engaging in any high-intensity or endurance physical activities. It is important for preventing muscle injuries and should be part of every athlete's routine to ensure safety and peak performance.
Muscle injuries can occur when a person starts an activity without proper preparation. Consequently, warming up can help prevent such injuries. Even though sweating is a mechanism for cooling the body during exercise, the warm-up process helps the body to adjust gradually to increased exertion levels, which can play a role in injury prevention.
Therefore, the correct answer to the question is 3) warm-up.