To determine moderate intensity heart rate using HRR, which statement is correct?

• A. Add 50-60% of HRR to resting HR
• B. Subtract 50-60% of HRR from resting HR
• C. Multiply resting HR by 0.5
• D. Add 20-30% of HRR to resting HR

Answer: (A)

The concept is using the heart rate reserve (HRR) with the Karvonen method to set a moderate-intensity target. You calculate HRR as max minus resting heart rate, then form the target by adding a portion of that reserve back to the resting rate: Target HR = HRrest + (HRR × %intensity). Choosing 50–60% of HRR to add to resting HR places you in the moderate range, because you’re roughly halfway up the available increase above resting. Subtracting a portion would reduce heart rate below resting and isn’t about effort, multiplying resting HR ignores the reserve and misrates intensity, and adding a smaller portion like 20–30% would yield light, not moderate, intensity.