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Introducing Strength Trainer: A New Way to Quantify The Impact of Your Strength Training

By Brice Rothenberg

Introducing Strength Trainer: A New Way to Quantify The Impact of Your Strength Training

Introducing a first-of-its-kind way to measure the Strain on your body during strength training. Strength Trainer quantifies the muscular load of your workouts by tracking weights, reps, and sets for a comprehensive view of your training efforts.

Quantify Your Strength Training

Most wearables only track your cardiovascular load during exercise using your heart rate, which is great for exercises like running, cycling, and other aerobic activities. However, if you do a very intense or heavy weight training session like powerlifting, your heart rate response isn’t proportional to the effort you give and the load your body sustains. No wearable has effectively quantified the impact of strength training on your body – until now. Strength Trainer fills a critical gap in the wearables space by quantifying both cardiovascular and muscular load for a comprehensive view of your training, allowing you to train more effectively and efficiently.

Calculating Muscular Load

For activities like strength training, measuring cardiovascular load alone doesn’t account for how hard your body is working. WHOOP has developed an algorithm to calculate muscular load – the amount of stress put on muscles, bones, joints, and tissues. Strength Trainer uses biomechanics to track the impact various strength training exercises have on your body. Different movements have different movement profiles and use a different percentage of the total musculoskeletal system. For instance, a back squat has a different load profile than a calf raise because it uses more muscles and joints, creating higher muscular load. Strength Trainer considers all of the movement profiles that are part of your workout session and quantifies your muscular load using the accelerometer and gyroscope sensors in WHOOP to understand the volume and intensity of your workout. It calculates the volume for each repetition of each exercise, measures the intensity for each repetition, and estimates the max volume based on your workout history to generate a unique muscular load for every strength training session.

How Muscular Load Influences Strain

When you use Strength Trainer, your Activity Strain will measure both cardiovascular load and muscular load. If you strength train regularly, you’ll likely notice higher Strain scores. Your Day Strain will also be higher on the days Strength Trainer is used to track weight lifting workouts, likely causing your Sleep need to be higher. These insights can help you make better decisions when it comes to planning your recovery and your next workout.

How to Use Strength Trainer

  1. Make sure you're wearing WHOOP on your wrist (and not in WHOOP Body apparel) as Strength Trainer algorithms currently account for movement from the wrist only.
  2. To plan your workout ahead of time: 
    1. Open your WHOOP app, and access Strength Trainer from the action button (+) or Plan tab under Overview.
    2. Build your own workout and enter your moves, weights, reps, and sets, or choose a pre-built option from some of the best trainers and athletes in the world including Rory McIlroy, Michael Phelps, Patrick Mahomes, Colleen Quigley, and Sloane Stephens. 
    3. Strength Trainer will quantify the muscular and cardiovascular load of your workout based on its volume and intensity. 

3. To log your completed workout: If you’ve already completed your power or weight lifting workout, box fitness, or functional fitness workout, you can tap into the saved activity and follow the prompts. You can also tap the action button > Add Activity> Strength Trainer.  

4. Your workout will get factored into your overall Strain score and will be considered in other metrics like sleep recommendations, to give you the most comprehensive view of your training yet.

What To Expect Next

With the launch of Strength Trainer, WHOOP is the first wearable that comprehensively measures both cardiovascular and muscular load. Whether it’s through a regular functional fitness routine or a strength training workout, members will get more credit for the work they do. This is the first step for WHOOP in the strength training space and we look forward to continuing to refine the feature.

What’s New

You can now log your strength training workouts after you’ve already completed them in Strength Trainer. Enter through the action button and tapping “add activity” to log your weightlifting or powerlifting workout after the fact, or tap into your completed workout and follow the prompts leading to Strength Trainer to get muscular load credit and a more comprehensive Strain Score.

We’ve also added more exercises to Strength Trainer to build your best workout including:

  • Spinning
  • Running
  • Stairmaster
  • Assault bike
  • Rowing
  • Elliptical

The content available through the WHOOP services may include training information or routines, and other media to help you meet your health, fitness, and wellness goals. WHOOP is not a healthcare provider, personal trainer or fitness instructor and these services (including any recommendations and any information available through these services that may appear to be personalized) may not be appropriate for you. WHOOP is not responsible for any results that may or may not be obtained from the use of these services.