The Whoop Strap 2.0 is a high-tech fitness tracker worn 24/7 that looks at everything from heart rate variability to sleep. The all-black device, worn on your wrist, is no larger than a set of matches. Athletes like Michael Phelps, Mike Mancias and Lawson Craddock all use it. Whoop is approved for use in the MLB and as a recovery tool for the NFL — even the Navy SEALS use it. Because of the high price point (think $500 for the device alone or $1,000 to $2,000 per player on professional and collegiate teams), the device was only available to elite athletes until recently. In May 2018, Whoop changed to a subscription model, charging $30 a month, and becoming accessible to the masses. I wore Whoop Strap 2.0 for over a month to test out the accuracy, ease of use and to see if it would change the way I work out.

The Good: The Whoop Strap 2.0 logs your movements 24/7, collecting data 100 times a second. Average heart rate, calories burned and your daily activity provide cues for what the device calls “day strain,” while heart rate variability and resting heart rate change your recovery score. Each night, the Whoop app tells you how many hours of sleep to get. It also tracks your time in bed and your sleep performance. These hard numbers are helpful if you know what to do with them, but luckily the app breaks down whether or not you need to sleep more, workout harder or improve your fitness.

Who It’s For: Whoop started just for elite athletes, but with the price reduction, the Whoop Strap 2.0 is more accessible to the everyday athlete. If you’re someone who is interested in improving your physical fitness, learning more about your sleep and reducing any chance of overtraining, Whoop is for you. Marathoners, triathletes and other endurance athletes will be able to monitor training schedules and adapt them as if a personal trainer was working with them directly.

Watch Out For: Initially, I had some issues connecting the band to the app and had to keep disconnecting and re-connecting my phone’s Bluetooth setting. Depending on your phone, it might take a few tries to connect.

Charging Whoop is a breeze in theory, but physically charging it on the go was a bit tricky. The device arrives with a portable battery charger that slides right on top of the Whoop band, so you don’t have to take the tracker off to juice it up. I struggled to remember the battery pack for the first few days, so there are more than a few hours of data missing from my training. I also had to get used to checking the battery life before bed because if I received a notification that the battery was less than 10 percent at 4 AM, there was no chance I was getting up to plug it into an outlet. There were a handful of times when I went to bed and woke up at 7 AM, only to realize that the battery had run out. But once I made it a routine to check the app, these instances occurred less frequently.

There’s no watch face, so Whoop won’t replace anything you already wear on your wrists. I like to wear my Apple Watch, but I can’t wear Whoop on the same side (because the Bluetooth signals can get crossed). I had to wear Whoop on the other wrist. Many people stopped me (even strangers in the subway) to ask me if I was wearing two Apple Watches.

Alternatives: There’s nothing else out there like the Whoop band. If you want a device that tracks your heart rate variability (an easy measurement to see how fast you’re improving athletically), the Polar H7, H10 Bluetooth Heart Rate Sensor ($60+) or the Garmin Premium Heart Rate Monitor ($31+) all measure it, but are all chest straps.

Review: Whoop comes in what looks like a Lego version of an individual cupcake holder. The bottom is a plug, so all you need to do is flip out the two arms, and plug in the USB cord to charge your device. The set up is simple and takes less than five minutes.

Compared to other fitness trackers, it’s relatively simple design-wise. The stock all-black strap is stretchy and easy to cut, so it works for wrists of all sizes. You don’t need to order a longer strap to fit larger wrists. The black device looks like plastic, but I had no issues with its durability. And if you need something a bit nicer, you can dress it up with a Hydroband, Truman or Churchill band.

The Whoop band can charge to about 60 percent in just 46 minutes. You can charge up the portable battery separately, so you never lose data due to a drained battery. While the battery pack adds bulk to your wrist, I hardly noticed it during the hour or so that I was charging it.

When I first opened the app, I had to familiarize myself with the three screens: day strain, recovery and sleep performance. It’s these three pillars of measurement that Whoop Strap 2.0 uses to calculate your levels of fitness.

It takes a baseline of four days of data before Whoop can provide adequate feedback and actionable steps. The daily strain is based on the stress put on the cardiovascular system over 24-hours, on a scale of 0 to 21. Intense workouts are 18 or above, while walking is somewhere between 10 and 14. Recovery is measured between 0 and 100 percent and is shown in three colors: red (run down), yellow (okay to operate) and green (peaking physically). The number comes from a combination of the questions you answer each morning after you wake up (are you stressed? sore? injured?) as well as your heart rate variability, resting heart rate and hours of sleep. Sleep performance is based on the total amount of sleep you need compared to what you actually get — also logged on a 0 to 100 percent scale.

For me, the key to using Whoop effectively was keeping my recovery score high, while also pushing my limits on strain (ideally over 10+) to continue improving my physical fitness. In June, my recovery score only dipped below 34 percent (in the red) three times, while it mainly stayed between 34 and 66 percent (in the yellow) and went above 66 percent only 12 days that month. Too many green days in a row meant that I could’ve worked harder.

During workouts, I didn’t have to tell Whoop I was exercising. It automatically tracked changes in heart rate and logged the workout. I trusted the app to log workouts for me.

The trifecta of scores would include a high recovery and strain score, with sleep performance clocking in at over 70-percent. Recovering sufficiently at night was where I failed most days. While I’m diligent about getting to a workout every day, sleeping the requisite number of hours each night proved to be more difficult. I only hit my goal ten days in June. Every other day I saw a message somewhere along the lines of “falling behind” or “getting by.” If I were to train for a race, I’d have to pay attention to exactly how much sleep I need to hit my peak performance, and not just “get by.”

Thanks to my daily check-ins with the Whoop Strap 2.0, I can now rattle off my heart rate variability (HRV) and resting heart rate (RHR) ranges and recognize immediately if those numbers are off. During a recent trip to the emergency room after a water skiing fall, the nurse took my RHR as 86, which I knew was off and meant something was probably wrong. I had been sitting in a car and the ER for over an hour, so there was no external strain on my body, and the number should’ve been no higher than 65 at that time of day. It turns out I broke my wrist, and my heart was merely responding to the issue.

Verdict: Despite not having a watch face, once I got used to checking the app every single morning on my way to work, it was easy to see how I was feeling and what workout I was down to try. One of the biggest mistakes athletes make is to train on empty, and when looking at the data from Whoop, it’s impossible to do that. Even if I woke up feeling like crap, if Whoop told me I was in the green, I took it as my cue to workout and push it as hard as I could. The tracker pushed me to new limits on days where I didn’t think I was ready, similar to the role a coach or personal trainer would play. As a data geek, it provided an easy-to-read insight into my physical stats. For upcoming marathons and triathlon training schedules, Whoop is an unexpected advantage. There’s no workout it can’t track. Whoop drastically reduces the risk of overtraining (and getting hurt) for elites and everyday athletes. For just $30 per month, this has the potential to be a game-changing tracker for anyone who needs an edge in fitness competitions or races, or if you need actionable advice from a tracker to improve your workouts.

What Others Are Saying:

• “Whoop is about hacking your performance, not putting something pretty on your wrist. As sleek as the band is, Whoop’s software is the true star of the show. Whoop is perfect for people who do activities like CrossFit or Iron Man competitions, where peak performance is essential.” — Brett Williams, Mashable

• “These professional athletes are strapping the WHOOP (rather than a Fitbit or Apple Watch) to their bodies because it provides an enormous amount of data on their performance day and night, in pre-game warmups and during post-game recovery. And if it’s good enough for the pros, it’s definitely fair play for this minor league father of two.” — John Patrick Pullen, Time

• “What makes Whoop different, in essence, are two key metrics: heart rate variability—a first for consumer fitness trackers—and sleep tracking. Whoop measures the amount of time you spent in light sleep, slow-wave (or deep) sleep, and REM; it also tracks how many times you woke during the night and your overall time in bed. The device functions as a pseudo-sleep coach, offering advice on how much your body has recovered and how hard you should train the following day.” — Matthew Giles, Men’s Journal

Key Specs

Band Material: Lightweight, flexible polyester woven fabric
Waterproof: Strap, yes. Charger, no.

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