Garmin Fitness Tracker and HRM - Accuracy? 700 calories for 60 mins badminton?

brock2k12

Hi guys,

I recently got a Garmin Vivofit fitness tracker that comes with a HRM chest strap.

Played an hour of badminton yesterday and my HRM strap said I burnt over 700 calories for 60 minutes. I am sure this cannot be accurate as I was only a casual game and online calorie calculators would estimate 300-400 calories based on my weight (5ft 2in, 147lbs).

Do you guys know how to make a HRM chest strap more accurate? I am sure this figure is not correct, right? It was not intense although I am unfit.

It also said that level 1 of Jillian Michaels shred was 275 calories which seems a little high.

Any advice would be great