For the past two days I did the same workout, Tuesday night and Wednesday night. Same level of intensity, same time of the day, everything. However, Tuesday night my fitness watch said I had burned over 800 calories. Last night it said I burned 140. I felt so great after Tuesday's workout, imagining that I had really burned THAT MANY calories. However, after last night's workout I was really frustrated and disappointed.

Anyone have any idea why the numbers would be so different? Or any tips on how to focus on the importance of just working out rather than burning a specific number of calories? It's just so discouraging. Thanks for listening.

what does your fitness watch do? is it a heartrate monitor? if so, was the heartrate strap put on properly during the activity? it could have not had enough moist or slipped too low to measure properly.

for me it's also that I have to reset it everytime before I workout, otherwise it adds up. once I accidently reset it in the middle of my workout.

if you use a hrm, you can check it yourself every few minutes to see where your heartrate is at and then use an online calculator to see what your calories burned are.

i have problems with discrepancies too although in a different format

on the treadmill, i get the same amount of "calories burned" reading whether i'm walking flat or at the max incline...it says i burn 180 calories for doing almost 3 miles of high incline walking at a fast speed...doesnt matter if i walk flat or climb hills, same calories burned...i leave the treadmill after 45 minutes soaked in sweat, dripping from my hair, and the treadmill's HRM says i'm keeping my heart rate between 145-175 the entire time (minus a few cool down minutes)

when i input the same workout into My Fitness Pal(is that what its called?) i get 400 calories burned instead of 180....ummm okay??

im assuming that i burned more than 180 total because i KNOW im working out hard, consistently, leaving covered in sweat and i do this almost daily....but i also fear overestimating by believing that i burned 400 calories

now you know why it's really rather pointless to try and track calories burned. i prefer to go by perceived exertion, time, or distance.