Weight lifting

[Umbrall]

To a degree. In general, excercises where you do not break the fatigue barrier are considered more efficient. Hence. walking, swimming, and cross country skiing.

[Ditcher]

Actually I recently read that there isint "right" heartbeat rate for burning fat. Just do the exercise as long as you can(60min+) and you'll be fine.... naturally this is easier if you dont tire yourself up during the first 10 minutes.