After my 2 hour e bike ride with over 1000 m incline in places I still only burnt 198 calories where Strava says 500. Each weightlifting session of an hour is approx 68 cals and yoga/pilates is 50. How does it calculate this?
Hey @Louise7791 - thanks for the post 
To calculate calories burned, we first estimate your Basal Metabolic Rate (BMR) using formulas based on your height, weight, and gender. Then, we add calories based on a proprietary mathematical function related to your heart rate. Once your heart rate exceeds a certain threshold, the formula becomes: Calories Burned = BMR + function(Heart Rate). This function is proprietary and aligns with academic findings on energy expenditure. You can read more of the details here.
Speaking from personal experience, I tend to know cardio will burn more calories than strength training - so that may explain some of the difference there. In terms of the difference between WHOOP & Strava - it’s safe to assume different tech will do the calculation differently, so I can’t comment on how Strava is counting to 500 on their end.
I’m also going to copy/paste this fantastic explanation from a colleague of mine who is an expert on the topic:
WHOOP relies heavily on continuous heart rate monitoring for calorie burn estimates. Higher HR generally correlates with increased calorie burn, but WHOOP will adjust to you over time. If you notice a major change in your calorie burn count, ensure WHOOP is flat on your arm, minimizing movement even during activity for accurate HR tracking.
Additionally, WHOOP also uses factors like age, weight, and height - which all affect basal metabolic rate (BMR, the calories you burn at rest) and energy expenditure and are included in the algorithm.
One thing to keep in mind with calorie burn numbers from ANY wearable device, including WHOOP, is that it is intended as a relative estimate. While WHOOP’s calorie tracking is highly accurate, it is recommended that you utilize the calorie burn data as an estimate rather than a true clinical measure. I would not base fueling entirely on a single calorie burn number, but it can be useful to know days where you are relatively more or less active and may want to consume more/less fuel.