Did the recommended 15 min on the cross trainer last night. Next week I'm going to push it up to 20 min.

Walked at lunch today for 35 min. - beautiful day - sunny, cool, crisp with a breeze. Started out in a light jacket, but took it off after about 5 min. warm-up - was hot by the time I was done (even though it's only about 60 degrees and I'm wearing short sleeves).