- A lot of valuable health metrics
- It keeps you connected to your body
- Alerts you to changes outside your typical baseline range
- Maximizes training and recovery for better athletic performance
- Provides the ability to download and easily share health data with physician or coach
- 33% smaller than the 3.0 version
- Intuitive smartphone app
- Waterproof wireless battery charger
- No time/watch feature
- Short battery life
Price: WHOOP 4.0 strap included free with $24/month membership when paid annually, or $30/month when paid monthly. WHOOP Pro additional $12/month includes four free items and added discounts.
Additional Straps: $49-$99
Obtained by: Company sample
RBR advertiser: No
Wearable Technology That Knows Your Body Better Than You Do
As soon as I hit Send to submit my WHOOP 3.0 Strap and app review, the company released WHOOP 4.0 and WHOOP Body. The key differences between the two versions are hardware, software, and the capability for the sensor to work in WHOOP Body products. The smartphone app continues to be easy to navigate and view all key health metrics. Read my WHOOP 3.0 review for in-depth app details.
How’s the Hardware Different from Version 3.0?
The sensor itself is 33% smaller, and the company upgraded the sensor configuration on the WHOOP 4.0. It now uses 5 LEDs with different wavelengths of light (3 green, one red, and one infrared), four photodiodes, and advanced algorithms to provide a more accurate heart rate.
The company upgraded the wireless battery pack, so it is now waterproof, which is perfect because I’ve accidentally showered with the charger on the sensor numerous times. However, I did find the battery life shorter than the 3.0 version; depending on my activity level, I typically need to charge my sensor every four days. In comparison, my Garmin Forerunner watch with wrist HR usually lasts over a week.
What’s Different with the Software?
WHOOP 4.0 offers several new software upgrades that help to monitor your daily health. The new hardware enables a pulse oximeter and the calculation of blood oxygen levels (SPO2). With COVID continuing to be a global concern, monitoring blood oxygen levels tell you how well your lungs are working and measure the acid-base balance in your blood. A low oxygen level could mean blood or water is filling the air sacs in the lungs.
A skin temperature sensor now measures your temperature while you sleep. It’s just another metric used for monitoring your health.
Another new feature is a sleep coach with haptic alerts, which you can set to wake you up using gentle vibrations at the optimal time. This time is based on your specific sleep needs and cycles. I never used this feature because I need to be up at a particular time each day and rarely have an optimal amount of sleep, which means I would most likely have overslept.
The WHOOP monitors various health metrics that you can download and export. These 30-day or 180-day trends are designed to be shared with your coach or physician. Metrics include heart rate, skin temperature, blood oxygen saturation, resting heart rate, heart rate variability, and respiratory rate. I found it very interesting to review these metrics continuously.
For example, seven days after receiving my COVID booster, the health metrics showed an elevation in my resting heart rate, a reduced recovery rate, and increased skin temperature. It simply confirmed how I was feeling post-booster. But on the eighth day, all my health metrics went right back to their pre-booster numbers.
The New WHOOP Body Product Line
With WHOOP 4.0, it’s now easier to remove the strap and use WHOOP Body featuring Any-Wear™ Technology, which gives users a variety of areas to collect data, including torso, waist, and calf. WHOOP Body is for those who don’t want to or can’t wear the hardware on their wrist like with some sports (e.g., volleyball).
The company sent me an Any-Wear Sports Bra to test. I requested a large after consulting their sizing chart, but it was too big when I tried it on. There was gapping under the arms and too roomy in the bust. I didn’t exchange for a medium because I felt that might have been a bit too tight.
The website says the racerback sports bra provides medium support, making it unsuitable for high-impact activities. The high-end construction with minimal seams prevents potential chafing. As a personal preference, I removed the pads for better breathability. The sports bra costs $79, comes in 3 colors (ice, black, and olive), and sizes XS to XL.
Even with the bra not fitting securely next to my side, the sensor recorded the data accurately. The heart rate was spot on without any “dead spots,” and it also picked up when I started cycling on my trainer. That still amazes me.
I noticed the company has an adjustable bralette that might fit me better than the sports bra. But if you decide to try the sports bra, I suggest sizing down. Men, don’t worry, there are WHOOP Body products for you, too.
The WHOOP 4.0 has a new design to allow easier and faster band removal, enabling you to use the sensor with the WHOOP Body products or swap out bands to suit your mood.
Partnering with Zwift
In January, WHOOP partnered with Zwift to offer a three-week training program for all levels. Based on your WHOOP physiological performance, these workouts were designed to balance optimal strain with functional recovery.
- Green – If your WHOOP showed green, your body is well-recovered and primed to go all out
- Yellow – When your WHOOP shows yellow, your body isn’t fully recovered, and you are only ready for a moderate effort
- Red – You are fatigued if WHOOP displays red. This means it’s time for an active recovery day or even a day off.
Anyone could sign up and participate in the Zwift/WHOOP workouts. I rode each color during the three weeks correlating it with my WHOOP recovery information. The sessions were inspired by professional cyclists, triathletes, and runners who use WHOOP, including Lionel Sanders and Alex Howes. I found these workouts were spot on the majority of the time. Two rides, I felt I could have gone higher.
The WHOOP 4.0 helps me stay tuned to my body through its comprehensive health metrics. The recovery percentage is spot on, and I adjust my training accordingly. Also, I find myself going to bed earlier to optimize my sleep performance. Getting up at 5:45 a.m. to ride was taking a toll on my health. I’m more rested and performing better by getting the optimal amount of sleep and allowing my body to recover. And it’s fun to play the recovery game. Every morning I take a mental assessment of how I feel and then see if the WHOOP app concurs. I sometimes don’t feel recovered, but my body begs to differ once I hop on the bike. Guess the WHOOP knows.
Sheri Rosenbaum regularly contributes articles and reviews products for RBR. She’s an avid recreational roadie who lives in the Chicago area and a major advocate for women’s cycling, serving on the board of directors and volunteering with the Dare2tri Paratriathlon Club. Click to read Sheri’s full bio or visit her web site sunflowersandpedals.com.