Amps I question the accuracy on the calorie burn count from the Apple Watch, but the heart rate monitor is accurate. Last sesh, hit an average BPM of 158, with a 750 calorie burn over an hour. Mostly nonstop drills and shadows (30 mins of alternating between backhand smash and forehand smash, half court - peaked at 190 on and off). Sure doubles, where it’s more about clever rotation and less movement, I can see people thinking it isn’t intense. But singles, full court is fucking beastly. Taken me a year to play singles full court with a tiny bit of respect.