Using the Heart Rate Reserve method, what is the target heart rate for a 40 year-old man with a resting heart rate of 70 beats/min, exercising at an intensity of 65%?

110 bpm is the Heart Rate Reserve itself (Max HR minus resting HR), not the final target HR - the resting HR was never added back.

129 bpm does not result from correctly applying the Karvonen formula at 65% intensity; it likely reflects a misapplication of intensity percentage or omission of a calculation step.

Using the Karvonen formula: Max HR = 220 - 40 = 180 bpm; HRR = 180 - 70 (resting) = 110 bpm; Target HR = (110 x 0.65) + 70 = 71.5 + 70 = 141.5, which rounds to 142 bpm. This method accounts for resting HR, making it more individualized than simply taking a percentage of max HR.

180 bpm is the estimated maximum heart rate (220 - 40), which represents 100% intensity, not a 65% training target.