My understanding is that activity calories are gross calories including BMR, and active calories are net calories beyond BMR, but it seems lately that the Active Calories are very low with respect to Activity Calories.
Yesterday, I had Active Calories of 175 or 200 before going to the gym and doing about 90 minutes of strength training with a chest strap (Wahoo TICKR X) connected to my VA 3, which came out to 405 calories. Then 30 fairly leisurely minutes on a bike for another 201 calories. After those two activities, my total Active Calories were under 400. 600 active calories in 2 hours only represented about 200 Active Calories?? This seems rather off to me..
This is all very different from what it would have been a few months ago. Some of that is me, but a bunch of it seems to be in the Garmin calculations, and I'm not sure how much is which. I had a back problem which resulted in back surgery in January, and virtually no exercise between November and February, which had it's impact on my strength and cardiovascular health. Since then, I've been working out like crazy, and lately I've been doing a lot more cardio, HIIT, etc. which has resulted in noticeable improvements in my resting heart rate and cardiovascular health overall. 2 and 3 months ago, similar workouts resulted in significantly higher Active Calorie burn.
How much of this is me and how much is Garmin calculations? Have others seen their Active Calories drop a lot?