WHOOP launches Strength Trainer feature

WHOOP said on February 20 that it launched Strength Trainer, a feature designed to measure the muscular load of weight training and fold that into the company’s Strain score. The Boston-based wearable company said the tool tracks weights, reps and sets and uses motion-sensor data from the device to estimate how much stress a workout places on the body. WHOOP described the feature as a way to give lifters a more complete picture of training load than heart-rate-based tracking alone. The company published feature details in a Locker post by Brice Rothenberg and in related support documentation. ### What exactly did WHOOP launch for lifters? Strength Trainer is a workout-logging and load-measurement feature inside the WHOOP app, according to WHOOP’s product post and support pages. WHOOP said users can track exercises, sets, reps and weight, while the device’s accelerometer and gyroscope help estimate exercise volume and intensity. WHOOP said the feature is built to quantify “muscular load,” which it describes as the stress placed on muscles, bones, joints and tissues during strength training. The company said that lets it account for workouts that may not produce the same cardiovascular response as running or cycling but still create substantial physical strain. (whoop.com) ### How does it change WHOOP’s Strain score? WHOOP’s support documentation says Strain is a personalized score from 0 to 21 that measures total exertion by analyzing cardiovascular load and muscular effort. In Strength Trainer sessions, the company said logged lifting data is used to calculate muscular load and feed that into the broader Strain score. (whoop.com) WHOOP said this produces a more complete training picture because resistance work can impose stress that heart rate alone may miss. In a separate explainer on Strain, the company said muscular load is now factored in through automatic estimation for some strength activities, through Strength Trainer logging, and through post-workout exercise linking. ### Do users have to log every set for it to work? (support.whoop.com) WHOOP said no manual logging is required for every strength session to generate a muscular-load estimate. In an April 23 explainer, the company said it can automatically estimate muscular strain for activities such as weightlifting, functional fitness, HIIT, powerlifting and bodybuilding based on activity type and duration. (whoop.com) Logging workouts in Strength Trainer, however, improves accuracy, WHOOP said. Its support page says the feature uses both entered workout details and sensor data, and the company’s newer explainer says post-workout exercise linking can also refine the result. ### What is WHOOP saying comes next? WHOOP said in its “What’s New” page for 2026 that Strength Trainer updates shipped on February 20 included lower-friction exercise linking powered by WHOOP AI and new ways to see strength progress over time. (whoop.com) The same page said WHOOP also added passive muscular-load estimation for weightlifting, functional fitness, HIIT and other activity types. (support.whoop.com) In a spring 2026 roadmap post published last week, WHOOP said Strength Trainer would get trends and personal records “this quarter.” That post also said deeper integrations with training apps are planned to bring more activity into WHOOP automatically. ### Where can users find the rollout details now? WHOOP’s main product article, published February 20 and updated in the company’s Locker hub, outlines how Strength Trainer measures muscular load and connects it to Strain. (whoop.com) WHOOP’s support center also has separate pages on Strength Trainer, Strain, and the list of activities where muscular strain is automatically calculated. (whoop.com) WHOOP said the next visible milestones are spring-quarter feature additions, including trends and personal records for major lifts. Those updates are listed in the company’s “What’s Next for WHOOP — Spring 2026” page. (whoop.com 1) (whoop.com 2)