What should be the primary focus of a warm-up before an exercise session?

The primary focus of a warm-up before an exercise session is to elevate the heart rate gradually. This process is essential because it prepares the cardiovascular system for the increased demands of physical activity. By gradually increasing the heart rate, the body can ensure that blood flow to the muscles is enhanced, which helps to deliver more oxygen and nutrients needed during the workout. Additionally, a proper warm-up can help to increase muscle temperature, which improves muscle elasticity and function, reducing the risk of injuries.

While increasing muscle strength is a vital aspect of an exercise program, it is not the goal of a warm-up. Similarly, while flexibility can be improved through stretching, this is typically not the primary aim of the warm-up. Lastly, resting the body before exercising does not align with the concept of a warm-up, as it is designed to activate the body and ready it for the physical activity ahead. Therefore, the most appropriate focus for a warm-up is indeed the gradual elevation of the heart rate.