Final answer:
The Karvonen method is the most accurate method for determining exercise intensity that accounts for Resting Heart Rate (RHR), using the formula: THR = (HRR × intensity) + RHR. It takes into account both Maximum Heart Rate, which decreases with age, and individual RHR.
Step-by-step explanation:
The most accurate method to determine exercise intensity that takes Resting Heart Rate (RHR) into account is the Karvonen method. This method calculates Target Heart Rate (THR) by first determining the Heart Rate Reserve (HRR) which is the difference between the Maximum Heart Rate (MHR) and the resting heart rate. The formula is: THR = (HRR × intensity) + RHR. Maximum Heart Rates (MHR) are normally in the range of 200-220 bpm but can vary with physical condition and age. MHR can be estimated by the age-predicted method, which is 220 bpm minus the person's age. For instance, a 40-year-old's estimated MHR would be about 180 bpm, and a 60-year-old's would be around 160 bpm.