How many calories will i burn.

Depends on how vigorous the activity. Do a search under exercise, choose the activity, put in the minutes, it will put in your weight and calculate for you. I checked yours and it gave 466 for the 110 min walk and 212 for the 50 min aerobics at 254/hr. The web based product has a list of all the activities so you can see them and choose one....don't recall how the app works with exercise. I used the minimum of 254/hour for both aerobics and walking which seems to be correct for me. If you look at the MFP database you will see there is a range for both activities that range from the 254 up to 500 or even 600 calories/hr, but I'd be pretty cautious using those kind of numbers and find a way to track them electronically. Most people only eat back half the calories until they are sure about the numbers.