Which factors should be controlled in an exercise and pulse rate investigation?

In an exercise and pulse rate investigation, it is crucial to control various factors to ensure that the results are valid and reliable. Controlling age, time of day, and weight can significantly impact heart rate responses to exercise.

Age can affect cardiovascular fitness and resting heart rate, as younger individuals might have different baseline pulse rates compared to older individuals. The time of day can influence exercise performance due to factors like fatigue or hormonal changes. Weight is relevant because it can influence cardiovascular efficiency and the body's response to physical activity; individuals with higher body mass might experience different heart rate responses compared to those with lower body mass.

By controlling these elements, researchers can minimize the variability in heart rate results that could be attributed to factors other than the exercise itself, allowing a clearer observation of the relationship between exercise intensity and pulse rate.