The Whoop 4.0 (available at Whoop) is a wrist wearable that records data about your fitness, sleep, and stress levels and churns out easy-to-understand scores to help you get to know your body better.

WHOOP 4.0 TV Spot, 'Anthem' Featuring Patrick Mahomes, Nelly Korda, John John Florence.

How does WHOOP work? Optical sensors in the WHOOP 4.0 band continually record your heart rate, heart rate variation, blood oxygenation, breathing rate and skin temperature.

Whoop has launched a new ad campaign with the help of some big names in fitness and performance, including Michael Phelps, rock climber Alex Honnold, Whole30 co-founder and CEO Melissa Urban, entrepreneur Steven Bartlett and soccer star Virgil Van Dijk.

The wearable WHOOP tracker is a two-in-one device that uses both fitness and sleep data. The goal is to calculate overall recovery, which WHOOP defines as how prepared you are for activities in the day ahead based on your recent exercise, heart rate, and how well you slept the previous night.

Whoop is a fitness-tracking and fitness-coaching wearable and app that uses physiological data to simultaneously improve your training and fitness. Its latest product is the Whoop 4.0 band, which is a sleek and comfortable wrist strap that can be worn and utilized 24/7.

It's a good health and fitness tracker, and the information provided in the app, along with its motivational tools and advice on when to sleep and recover, is valuable. However, it doesn't provide more than the competition, and that makes the overall cost of owning and using the Whoop problematic.

WHOOP 4.0 debuted in 2021, with battery technology developed by Sila Nanotechnologies that replaces graphite anodes with silicon, thus increasing battery capacity. WHOOP 4.0 consists of a removable knit strap that is attached to the monitor. The battery is water-proof and can charge the device while in use on the body.

Sports

• WHOOP has been approved as a fitness wearable by various professional sports leagues and their labor unions.
• The wearable is popular among celebrity athletes, including swimmer Michael Phelps, basketball player LeBron James, and golfers Rory McIlroy, Nelly Korda, and Tiger Woods.

Will Ahmed Will Ahmed, Founder and CEO of WHOOP.

WHOOP calculates multiple different scores, from sleep to strain, and from stress and recovery, providing personalized information that can positively impact several areas of everyday life. WHOOP Sleep provides an in-depth look at sleep performance and lets you know how much sleep you need.

athletes WHOOP is an American wearable technology company headquartered in Boston, Massachusetts. Its principal product is a fitness tracker that measures strain, recovery, and sleep. The device is best known for its use by athletes.