Weight Lifting

Put it under cardio. Strength training weight lifting.

Even an HRM cannot accurately count calories burned. Just because your heart rate is high doesn't mean you're burning the same amount of calories as when you are doing an aerobic activity.

The reason the HRM is not valid for weight training is that the physiology underlying the heart rate increase when lifting weights is different than with cardio, so the increase in HR that occurs when lifting weights does not reflect the same increase in VO2 (oxygen uptake, the basis for calorie estimations) as cardio exercise. HRM are calibrated to the the HR response to cardio exercise, not weight training.

Even when there is an increase in VO2 with strength training (e.g. lighter weights, some types of circuit training) the increase is less that what you would see at a similar HR during cardio exercise, often 30%-40% less.

Bottom line, HRM calorie readings cannot be used to *kitten* caloric expenditure during weight training. Any "trainer" that says differently does not understand basic exercise physiology.

also, Read this:

http://www.myfitnesspal.com/blog/Azdak/view/hrms-cannot-count-calories-during-strength-training-17698

If you're doing intense weight lifting, go ahead and log it under cardio as strength training. MFP estimates strength training calories burned super low to be on the safe side so you might as well give yourself credit for those calories.