Which formula represents heart rate reserve (HRR)?

Which formula represents heart rate reserve (HRR)?

• A. HRR = HRrest - HRmax
• B. HRR = HRmax / HRrest
• C. HRR = (HRmax + HRrest) / 2
• D. HRR = HRmax - HRrest

Answer: (D)

Heart rate reserve is the range of heart rate available for increasing above resting up to your maximum. The correct formula captures that range by subtracting resting heart rate from maximum heart rate: HRR = HRmax − HRrest. This difference shows how much your heart rate can rise during activity. Using the difference is important because it reflects the actual potential increase, which is why you can apply the Karvonen method to set training intensities: Target HR = HRrest + (HRR × desired intensity). For example, if someone has a maximum heart rate of 190 bpm and a resting heart rate of 60 bpm, the HRR is 130 bpm. Training at 65% intensity would aim for a target of 60 + (0.65 × 130) ≈ 145 bpm. The other expressions don’t represent the reserve: subtracting HRmax from HRrest would yield a negative value, a ratio or an average doesn’t describe the available range, so they aren’t HRR.

Heart rate reserve is the range of heart rate available for increasing above resting up to your maximum. The correct formula captures that range by subtracting resting heart rate from maximum heart rate: HRR = HRmax − HRrest. This difference shows how much your heart rate can rise during activity.

Using the difference is important because it reflects the actual potential increase, which is why you can apply the Karvonen method to set training intensities: Target HR = HRrest + (HRR × desired intensity).

For example, if someone has a maximum heart rate of 190 bpm and a resting heart rate of 60 bpm, the HRR is 130 bpm. Training at 65% intensity would aim for a target of 60 + (0.65 × 130) ≈ 145 bpm.

The other expressions don’t represent the reserve: subtracting HRmax from HRrest would yield a negative value, a ratio or an average doesn’t describe the available range, so they aren’t HRR.