Final answer:
The American College of Sports Medicine recommends an exercise intensity range of 60-75% of heart rate maximal for adults using HRmax.
Step-by-step explanation:
The American College of Sports Medicine recommends that adults use a heart rate maximal (HRmax) of 60-75% for their exercise intensity. HRmax is estimated by taking the maximal value of 220 bpm and subtracting the individual's age. For example, a 40-year-old person would have an estimated HRmax of approximately 180.