The maximum heart rate, in beats per minute, that you should achieve during exercise is 220 minus your age, 220 minus a. your exercise goal is to improve cardiovascular conditioning. use the following formulas to answer parts a and b. lower limit of range hequalsseven tenths left parenthesis 220 minus a right parenthesis upper limit of range hequalsfour fifths (220 minus a) a. what is the lower limit of the heart range, in beats per minute, for a 43-year-old with this exercise goal? the lower limit of the heart range is nothing beats per minute. (round to the nearest integer as needed.)