Calorie burn on Apple Watch

[LakeFlyPie]

Did Spin class this morning. Followed instructor's recommended resistance levels;sweated, leg muscles burned, out of breath as per usual.
Apple Watch recorded 275kcal for 45 min class (indoor cycle workout) Overheard someone in changing room say to instructor that she'd burned 600 kcals 😳
I know there'll be some variance in measurements on wearable tech and calories burn will be different according to age etc (I'm 49 and overweight!) but how did she do same class and burn more than twice as many calories?

Firstly, wrist based heart monitoring can be quite inaccurate, particularly once you get sweaty IME! Is your watch only giving you the "exercise" calories, rather than total calories burned in 45min? i.e. it deducts the amount you would burn if you were doing nothing? It will also depend how hard you're working but yours sounds low and hers sounds high. 100 calories per 10min of intense cardio is a decent guide for women (unless you're particularly tall and heavy)

Different watches measure the calories burned in different ways. Fitbit measures resting calories as well as active calories but Apple only measures active calories.

I've owned both and you'll always get more calories with the Fitbit purely because it starts at midnight and counts your resting calories.

If you look at the detail in your Fitness app it will show you the total calories as well as active calories. My strength workout this morning was 139 active calories, 233 total calories for example. But being overweight will mean you burn more calories not less - my friend used to complain that her watch would record fewer calories than me for the same workout, until I pointed out that if she's like to do it with a 30kg weight vest on then she would burn more too...

600 in 45 minutes sounds unfeasible unless the other person was very tall, very heavy but also very fit and reaching very high heart rates. They probably counted total calories since midnight last night.

Thanks, good points.
275 was ex kcal: total 365 which is a bit better.
It is always a bit disappointing how few calories exercise burns (however intense). I could eat double that without breaking a sweat!

I do feel fitter and stronger though 💪

365 in total sounds fairly realistic then, given that in a 45min class you're not working flat out for the full time.

Felt like it 😆

I'd say hers was lying to her, yours seems more accurate for that sort of time... exercise really doesn't burn anything like as much as it feels it should!
Try your watch on the other side of your wrist, I usually wear mine on the outside but for exercise I flip it to the inside and it registers heart rate more accurately there when sweaty.