What are the primary physiological benefits of an effective warm-up before training or competition?

• A. Increases muscle temperature, nerve conduction velocity, enzyme activity, and joint mobility, and prepares the cardiovascular and respiratory systems.
• B. Decreases heart rate and slows metabolism during warm-up.
• C. Increases fatigue resistance by depleting glycogen stores.
• D. Causes muscles to contract more slowly to reduce injury risk.

Answer: (A)

Starting with the main idea: an effective warm-up prepares the body for activity by boosting tissue readiness and the systems that support performance. When you warm up, muscle temperature rises, which makes muscles more pliable and joints more mobile due to looser connective tissues and synovial fluid. Nerve signals travel faster as nerve conduction velocity increases, helping with coordination and quicker, more precise movements. Enzymes and metabolic reactions also work more efficiently at higher temperatures, so energy production ramps up more quickly when you start exercising. At the same time, the cardiovascular and respiratory systems are stimulated: heart rate and stroke volume rise, delivering more oxygen to working muscles, and breathing becomes more ventilated to meet the upcoming demand. All these changes together enhance performance and help protect against injury.

The other ideas don’t fit what a proper warm-up does: it doesn’t lower heart rate or slow metabolism; it doesn’t purposefully deplete glycogen to boost fatigue resistance; and it doesn’t aim to slow muscle contractions—rather, it improves neuromuscular readiness and performance as activity begins.