The change of maximum heart rate (MHR) is the same from ages 20 to 26. At age 20, a person has an MHR of 200 bpm and at the age of 26, a person has an MHR of 194 bpm, there's a 4 bpm difference. While at the age of 40, a person has an MHR of 185 bpm and at the age of 46, a person has an MHR of 182 bpm, there's a difference 4 bpm. Therefore, the change in MHR for the same range (20-26) and (40-46) are the same.