Why HRmax is important

Simply put, HR_max is the upper safe limit you should push your heart rate to during exercise; and knowing your HR_max 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 HR_max 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
40	180	194
50	170	188
60	160	182
70	150	175
80	140	169
90	130	162

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, HR_max is not something you can control.  While good genes may help you somewhat, overall, the decline in HR_max is independent of age, gender, and fitness level.  In other words, the decline in HR_max as we age is natural and out of our control.

The decline in HR_max with age should be a consideration when you choose a fitness class.  If the instructor is younger than you, their HR_max could push your HR_max 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.