I would suggest getting a heart rate monitor. This is like the 3rd time I've posted this on a message board in the past 10 minutes I think..haha. But I absolutely love mine and it gives a more accurate read out of what you actually did. I use mine for cardio and strength training, and it helps me keep track of not only calories and time, but also how hard I am working so I don't over exert myself. Polar makes some pretty good monitors that aren't too expensive. Also, go with one with a chest strap. Much easier to use.
As a very simple guide, most people burn between 6 and 10 calories per minute working out.
5-6 cal/min would be typical of brisk walk, so if you felt you were working out more intensely than that, then your calorie burn would more likely be in the 8-10 range.
Fitness Minutes: (15,905)
9,717 7/5/13 11:35 A
Depending on what she's having you do, you could use the general aerobics (high/low impact) or circuit training options.
Fitness Minutes: (7,832)
138 7/5/13 11:15 A
I finally bit the bullet & am hitting the gym. I am using a personal trainer for 1 hr/week. She has me doing a variety of cardio exercises - mostly 5-10 min each - & some stretching. I want to track this, but wasn't sure how. I could just enter 50 min cardio (accounting for 10 min moving from one activity to another), but I have no idea how many calories to count.