How can a heart rate monitor aid an athlete's exercise regimen?

• A. It calculates the target heart rate zone of roughly 15-45%
• B. It calculates the maximum heart rate of 150 minus biological age
• C. It calculates the target heart rate zone of roughly 50-85%
• D. It beeps if the runner is about to have a heart attack

Answer: (C)

Using a heart rate monitor helps regulate exercise intensity by targeting a specific heart rate zone during a workout. By staying within about 50–85% of your estimated maximum heart rate (often calculated as 220 minus age), you ensure the effort is appropriate for improving cardiovascular fitness and endurance. The monitor provides real-time feedback and alerts when you drift outside your zone, making it easier to pace yourself and progress safely over time. This focus on controlled intensity is why a heart rate monitor is a practical tool for guiding training, rather than aiming for very low effort or relying on an incorrect max-HR calculation.