How should intensity be adjusted for an individual with a low resting heart rate?

• A. Use HR Reserve targets and/or RPE, since HR-based targets may be less informative with very low HRrest.
• B. Always use heart-rate zones based strictly on maximum heart rate.
• C. Ignore any HR measures and use only RPE.
• D. Use fixed pace targets regardless of HR.

Answer: (A)

When someone's resting heart rate is very low, intensity should be guided by measures that reflect the body's true available cardiac output and how hard the effort feels. Heart-rate reserve targets do this by using the range between maximum and resting heart rate, then applying a percentage of that range to set training zones. This personalizes intensity to the individual’s actual capacity, which helps avoid misjudging effort when resting rate is unusually low. Perceived exertion (RPE) adds another layer because it captures how hard the workout feels, a reliable proxy for internal load that can reflect fatigue and metabolic stress even if the heart rate response is atypical or blunted. Using HR reserve targets and/or RPE provides a more accurate and flexible way to dose intensity in someone with a low resting heart rate, whereas relying solely on heart-rate percentages based on maximum heart rate can misrepresent effort. Fixed pace targets, or ignoring HR measures altogether, don’t account for individual physiological differences and can lead to mismatched training stress.