A patient jogs at 5 mph (8 METs). Using HRR terminology, this corresponds most closely to:

• A. 20-39% HRR
• B. 40-59% HRR
• C. ≥90% HRR
• D. 60-89% HRR

Answer: (D)

Heart Rate Reserve (HRR) defines exercise intensity by looking at how far the heart rate moves from resting toward maximal effort. The common ranges are light about 20-39% HRR, moderate about 40-59% HRR, vigorous about 60-89% HRR, and near-max about 90-100% HRR. Jogging at 5 mph, listed as 8 METs, is a level of effort that falls into the vigorous category for most people. That means the heart is working roughly 60-89% of its HRR. For a concrete sense, if resting HR were 60 bpm and estimated max HR 180 bpm (HRR = 120), spending time around 60-89% of that HRR would place your current HR in the ~132-167 bpm range, which aligns with vigorous activity. So the closest HRR range for this jogging intensity is 60-89% HRR.