Final answer:
The optimal heart rate range during moderate exercise is generally 50-70% of an individual's maximum HR, which can be estimated by subtracting the person's age from 220 bpm.
Step-by-step explanation:
The optimal heart rate range for moderate exercise in a standing flat position typically corresponds to 50-70% of an individual's maximum heart rate (HR). To estimate an individual's maximum heart rate, you can subtract their age from 220. For example, a 40-year-old's estimated maximum HR would be 180 beats per minute (bpm), and for moderate exercise, their target HR zone would be approximately 90-126 bpm.
A 60-year-old's estimated maximum HR would be 160 bpm, making their target HR zone for moderate exercise around 80-112 bpm. The provided range of 150-170 bpm could be suitable for younger individuals or very fit persons, as this range might represent vigorous to high-intensity exercise levels for many people. Always consider individual fitness level, health status, and doctors' recommendations when determining the optimal exercise intensity.