What is heart rate reserve (HRR) and how is it used to prescribe training intensity?

What is heart rate reserve (HRR) and how is it used to prescribe training intensity?

• A. The resting heart rate divided by HRmax
• B. The product of HRmax and HRrest
• C. The difference between HRmax and HRrest
• D. The sum of HRmax and HRrest

Answer: (C)

Heart rate reserve represents the range between resting heart rate and maximum heart rate, capturing how much the heart can be pushed above rest. It’s used to tailor training intensity with the Karvonen method: target heart rate equals resting heart rate plus a chosen fraction of the reserve. In formula form, Target HR = HRrest + (fraction of HRR) × (HRmax − HRrest). The essential point is that HRR is the difference between HRmax and HRrest, not a product, sum, or ratio of the two. This approach accounts for individual differences in resting heart rate, so training zones reflect each person’s true capacity. For instance, if HRmax is 190 bpm and HRrest is 60 bpm, HRR = 130 bpm. A 50% intensity would aim for 60 + 0.5 × 130 = 125 bpm, rather than simply using a percentage of HRmax. Training zones commonly fall within 40–60% HRR for moderate effort and 60–85% HRR for vigorous effort, enabling precise, personalized prescription based on the individual’s heart-rate capacity.

Heart rate reserve represents the range between resting heart rate and maximum heart rate, capturing how much the heart can be pushed above rest. It’s used to tailor training intensity with the Karvonen method: target heart rate equals resting heart rate plus a chosen fraction of the reserve. In formula form, Target HR = HRrest + (fraction of HRR) × (HRmax − HRrest). The essential point is that HRR is the difference between HRmax and HRrest, not a product, sum, or ratio of the two.

This approach accounts for individual differences in resting heart rate, so training zones reflect each person’s true capacity. For instance, if HRmax is 190 bpm and HRrest is 60 bpm, HRR = 130 bpm. A 50% intensity would aim for 60 + 0.5 × 130 = 125 bpm, rather than simply using a percentage of HRmax. Training zones commonly fall within 40–60% HRR for moderate effort and 60–85% HRR for vigorous effort, enabling precise, personalized prescription based on the individual’s heart-rate capacity.