Simply put, HRmax is the upper safe limit you should push your heart rate to during exercise; and knowing your HRmax is important to ensure you meet your workout goals without putting your body at risk of a potentially catastrophic failure.
The old (standby) formula for calculating HRmax is “220 minus age.” However, studies by the Norwegian University of Science and Technology have shown that this equation over simplifies things (especially as we age) and could underestimate the maximum safe HR by as much as 40 beats per minute. The HUNT fitness study (2012) resulted in a new formula “220 minus (0.64 x age).”
|Age||HRmax old formula||HRmax new formula|
Caveat: This is your upper threshold of safety, not your target heart rate during exercise [more on that next week].
Unlike chronic conditions and functional independence, HRmax is not something you can control. While good genes may help you somewhat, overall, the decline in HRmax is independent of age, gender, and fitness level. In other words, the decline in HRmax as we age is natural and out of our control.
The decline in HRmax with age should be a consideration when you choose a fitness class. If the instructor is younger than you, their HRmax could push your HRmax to unsafe levels. This doesn’t mean you have to give up your favorite class, it just means you should modify your activity accordingly (i.e., kick it down a notch if necessary).
If you want to workout without having to worry about being off step or putting your heart at risk, consider a peer fitness class where the instructor has designed classes to fall within safe parameters for your age group.