Heart Rate Reserve

Heart Rate Reserve tells you how many beats per minute you can add above your resting level before reaching your estimated maximum. It works by subtracting the baseline heart rate from the top end of your cardiovascular capacity, so the result reflects the training "room" actually available to you. This is useful because two people can have the same maximum heart rate but different resting heart rates, which changes how much reserve each person has.

Use this formula when designing or interpreting exercise intensity, especially for heart-rate-based training plans. It is also helpful when estimating target training zones with methods like the Karvonen approach.

• Subtracting maximum heart rate from resting heart rate, which gives a negative number
• Using a guessed resting heart rate from exercise instead of a true resting measurement
• Confusing heart rate reserve with target heart rate, which is a percentage of the reserve rather than the reserve itself