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I wore the Whoop strap this summer. Here’s what I learned.

A photo of the Whoop 4.0 band.Whoop

I can drink coffee in large quantities at any time of day. But alcohol is bad. And don’t eat too close to bedtime.

Those are personalized recommendations for my health based on the data I’ve been supplying to Whoop since early June, when I started wearing the Boston company’s newest wrist strap.

I say wrist strap because, unlike my Apple Watch, the Whoop isn’t a watch. It’s a five-sensor device attached to a piece of fabric that sits around my wrist 24/7, collecting health data.

The Whoop measures my heart rate, resting heart rate, heart-rate variability, skin temperature, and blood oxygen levels.


Whoop isn’t trying to be a smartwatch, but an obvious drawback is that the device doesn’t have a screen. (I still wear my Apple Watch when I run so that I can view my mileage and pace.)

For a $20 monthly membership fee, I get access to Whoop’s smartphone app. (I paid upfront and got a discounted rate, but Whoop’s monthly membership is $30.) The app uses proprietary algorithms to analyze and present data in three categories: cardiovascular strain, recovery, and sleep.

The Whoop band and smartphone app.

Strain appears as a number from 1 to 21. High scores reflect days of intense exercise, such as running. (My peak strain score this summer was 19.5.)

Recovery scores appear as a percentage and are based on how well a user recovered from the previous day.

Sleep performance measures how many hours of sleep you got, compared to how many hours Whoop thinks you needed. Last night I got 6 hours and 46 minutes of sleep, but Whoop recommended I get 9 hours and 2 minutes to reach 85 percent of my “sleep need.”

(Fun fact: Whoop employees who achieve 85 percent of their sleep need on average for a month receive a $100 bonus.)


Whoop encourages users to “journal” activities to see how certain choices and behaviors affect their physiological data. The list of things to track is extensive, including eating plant-based foods or spending a lot of time on work video calls.

I chose to track coffee, water, and alcohol consumption, how late in the day I ate food, and several others. Whoop creates monthly reports, which indicate whether those activities had a positive, negative, or neutral effect on my health.

A screen shot of my monthly Whoop report.Whoop

My monthly report showed that caffeine intake had no impact on my health, no matter how many cups of coffee I drank. But other people, like Whoop CEO Will Ahmed, might learn that coffee has a negative impact on their sleep. Ahmed now chooses to limit caffeine to before 2 p.m.

It’s important to remember that the Whoop is “only for recreational purposes.” The strap has not been cleared by the US Food and Drug Administration, and Whoop says it is “not intended to diagnose, monitor, treat, cure, or prevent any disease or condition.”

While it’s fun to know more about my sleep and lifestyle behaviors, I haven’t made any major changes because of the device. Whether I end up doing that could determine whether I renew my subscription, which cost $480 upfront for two years and amounts to more than my gym membership.

For Whoop to be effective, users have to act on the recommendations and change lifestyle behaviors, whether that means going to sleep earlier or taking more rest days.


“Whoop is not a magic bullet that will transform your sleep just by wearing it,” a spokesperson said. “The aim of the platform is to help people better understand their bodies, develop new habits, and improve their holistic health through personalized insights and recommendations.”

Anissa Gardizy can be reached at anissa.gardizy@globe.com. Follow her on Twitter @anissagardizy8 and on Instagram @anissagardizy.journalism.