Question

as alex continues his regular workout regimen, he sees significant improvements in his fitness levels. one of the most notable changes is a decrease in his resting heart rate (rhr), which has now dropped to 55 bpm, indicating improved cardiovascular efficiency. with this positive development, alex understands the importance of recalculating his target heart rate (thr) to ensure his workouts remain effective and tailored to his improved fitness. why does alex need to recalculate his thr?
a lower rhr could suggest that he is not exercising enough.
a change in rhr affects his maximum heart rate calculation.
a lower rhr indicates improved fitness, shifting thr zones to higher intensities.
a lower rhr means he needs to reduce his exercise intensity to avoid overtraining.

Explanation:

• Option A: A lower RHR shows improved fitness (from better cardiovascular efficiency), not that he’s not exercising enough. Eliminate A.
• Option B: Maximum heart rate (MHR) is typically calculated as \( 220 - age \), and RHR doesn’t affect MHR. Eliminate B.
• Option C: As fitness improves (lower RHR), the THR zones (which relate to intensity based on fitness) shift to allow for higher intensities because the heart is more efficient. This makes sense for recalculating THR to match improved fitness.
• Option D: A lower RHR means the heart is more efficient, so he can handle higher intensity, not that he needs to reduce intensity to avoid overtraining. Eliminate D.

Answer:

C. A lower RHR indicates improved fitness, shifting THR zones to higher intensities.