In %HRR categories, which range corresponds to near-maximal to maximal effort?

• A. <40%
• B. 40-59%
• C. ≥90%
• D. 60-89%

Answer: (C)

Understanding which portion of heart rate reserve corresponds to near-maximal to maximal effort. In the HRR framework, exertion is defined by a percentage of the difference between maximum heart rate and resting heart rate, added to resting heart rate. As that percentage increases, effort increases. Near-maximal to maximal effort is indicated by reaching at least 90% of that reserve, meaning you’re using most of your available cardiovascular capacity. For example, if HRmax is 190 bpm and HRrest is 60 bpm, HRR is 130 bpm. 90% of HRR is 117 bpm, so target would be 60 + 117 = 177 bpm—very close to max. The lower ranges map to lighter or more sustainable efforts (below 40% light, 40–59% moderate, 60–89% vigorous) and do not reflect near-maximal intensity.