A few weeks ago, my Forerunner 735xt started giving me wildly inaccurate estimates of total calories burned for an activity and for training effect. For example, I was in a 5K race a couple of weeks ago, which I ran in 25:06. Garmin said that I burned 250 calories, in contrast to multiple sources online that state that I burned somewhere between 325 and 399 calories. Here is a second even more extreme example. I cross country roller skied for 15 km yesterday at a pace of 10 km per hour. The unit said that I burned 480 calories, which is about one-third the correct result (it should have indicated approximately 1500 calories). I never had this problem with my prior Garmin unit that did not measure heart rate. I have ordered a Garmin strap heart rate monitor. Should this fix the problem?
