To determine when Huda has achieved a moderate-intensity workout according to CDC standards, it's important to understand the general guidelines for heart rate intensity levels:
- Moderate-intensity exercise is typically defined as activity that raises your heart rate to about 50% to 70% of your maximum heart rate.
Given this information, Huda will most likely know she has achieved her goal when she reaches about 64 percent of her maximum heart rate.
Thus, the correct choice is:
when she reaches 64 percent of her maximum heart rate.