Calorie claims of exercise classes and Strava

This machine burns more calories per minute than any other– up to 800 calories in a 45-minute session” (SWEAT by BXR | VersaClimbing)

Strava shows: Morning Elliptical 1h36m 1,115Cal 136bpm.

If the ad and Strava mean calories (small calories), not kilocalories (large calories), then the unit Cal must be a typo for cal – see “Calories” vs “calories” – History of Science and Mathematics Stack Exchange.

Both “up to 800 calories in a 45-minuteand 1,115 cal in 1h36m are less than the basal metabolic rate of 1200kcal/day =50kcal/h =50,000cal/h. (Examining Variations of Resting Metabolic Rate of Adults: A Public Health Perspective – PMC (nih.gov)) Thus false. The marketing claims probably intend to say kilocalories.

The sustained (an hour or more) power output of elite cyclists is about 400W. (Lance Armstrong: Cycling Power | CIO , Tour de France 2009: Power estimates (sportsscientists.com) )

1W =1J/s =3600J/h, so 400W =1440kJ/h =344 kcal/h because a calorie is 4.184 Joules.

Less-than-elite athletes likely burn significantly fewer calories than 344kcal in an hour, especially when not competing. Any exercise class, app or sports watch claiming over 200 kcal/h is suspect.

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