Fitbit Alta Review

Your fitness tracker is probably broken, here’s how to fix it

Lock down work outs aren’t easy. You should be commended just for getting out of bed during these tough times but the fact that you’re rolling out a mat and getting sweaty? Immediate Kudos. However, there’s a good chance you’re getting super frustrated with yourself if you’re using a fitness tracker. You’re pushing hard for 30 to 60 minutes, you’re red in the face, sweaty as all hell but… the stats on your fitness watch are saying you really didn’t do all that much.

Here’s the thing:


…. if you’re a woman.

fitbit blaze review

For years, medical research has ignored women and assumed our bodies work the same way as men. So, for years, we assumed the best way to calculate women’s peak or maximum heart rates was the same as men’s: 220 – age. That puts my peak heart rate at 190. 

After wearing my very first heart rate capable Fitbit (which uses this formula) through several cardio-based workouts and not reaching my cardio zone, I knew something was up. As it turns out, a new formula for women was introduced in 2010, following a study of over 5 400 asymptomatic or healthy women and is still considered the best calculation for women. 

The revised formula for women is 206 – 0.88(age), or 206 minus 88% of your age. This puts my peak heart rate at 180. As soon as I updated my peak heart rate on my device, what I was seeing on my fitness tracker and how my body felt during a workout finally lined up. 

If you own a Fitbit device that tracks Heart Rate, here’s how to update your peak heart rate:

Fitbit Alta HR Review
Juicy Couture bracelet, Pandora bracelet and Adawnment ring


  • Open the Fitbit app on your smartphone
  • Click your profile pic in the top left corner
  • Scroll down to Settings > Heart Rate Zones (it’s right at the bottom past Privacy & Security)
  • Move the slider for Custom Max Heart Rate to the right > Edit your Max Heart Rate as per for the formula shared in this post
  • Sync your fitness tracker again to update it


If you take three things away from this post let it be this:

Smartwatch review

  1. When it comes to health and physiology, women are not smaller men
  2. To calculate your peak heart rate as a woman, minus 88% of your age from 206
  3. Gadgets are great, but its best to listen to your body

To read the study in full and for free, click here

For simplicity’s sake, “women” here refers to cis-gendered female humans. Sex and gender are spectrums, so if you fall anywhere in between, it’s best to talk to your health care practitioner.

More Stories
Can this website guess your age? Microsoft’s how-old.net

I'd love to chat to you some more.


I usually send out a weekly mailer with a recap of blog posts but also some personal anecdotes. If you want to know about competitions or just catch up in a more personal setting then you might like to receive the mailer.

Enter your email and get the scoop first: