Ask the Doctor: ‘My gym say our max heart rate is 22bpm minus our age — is this true?’

“I have recently bought a heart rate monitor chest strap to wear at the gym as they are encouraging us to stay in certain parameters of our ‘max HR’ for certain durations during our workouts. My question, they calculate our max HR by using 220bpm and taking away our age, so max HR for a 40 year old would be 180bpm. Is this a safe and correct assumption or should I be seeking medical advice? I have never had heart issues but want to ensure I do things properly and don’t take heart rate advice from a non-doctor!”

Answer from Prof Jonathan Lyne, Director of Electrophysiology and Consultant Cardiologist & Electrophysiologist, Beacon Hospital.

Many thanks for this very interesting question. As wearable heart rate monitoring devices become increasingly accessible, it is indeed crucial for people to know this information and know how to interpret the data collected and displayed by the wearable devices to recognise situations where seeking medical help is warranted.

The formula 220bpm minus age in years is indeed used to get an approximate value of the maximum predicted heart rate, but it is important to realise it does not take into account gender, fitness levels, and other medical conditions that affect the heart rate. Furthermore, along with the calculated absolute value, other confounding factors like the environment and situation accompanying heart rate rise, and any associated symptoms are of equal importance.

For example, in a fit and healthy young individual like yourself, a gradual heart rate rises up to 180bpm during exercise without any symptoms, which gradually settles on cessation of exercise back to normal would be considered a normal physiological response.

However, if the heart rate change displays a sudden and instantaneous pattern, rising for example from 70-80bpm to 160-180bpm and returning to normal in an instant mimicking a ‘switch on switch off’ mechanism, then further investigations would be warranted.

Similarly, the presence of any symptoms such as chest discomfort, unexplained shortness of breath, light-headedness, dizziness, or loss of consciousness with an increased heart rate, even if it falls within the normal predicted heart rate would warrant urgent medical attention.

If any concerns exist I would highly recommend you discuss them with your own doctor or a specialist without delay, as heart rhythm issues are extremely common and can be present in any age group and in people who are otherwise extremely fit and healthy.

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