Why an outdoor workout at the track? "Muscular endurance is your muscles' ability to contract over a long period of time, and it increases through short bursts of high-intensity exercise and interval training," says Dori Madsen, a personal trainer. This also means that muscle-endurance training burns kilojoules faster than Oprah doles out millions. The track provides easy, measurable distances that you can mark off for sprints, laps, and other interval exercises; and thestadium stairs force you to use your own power (versus the treadmill's belt or the weight machine's cables). The less assistance you have when doing exercises, the more endurance you'll build.

Workout Exercises:

Warm-up Jog around the track for five to 10 minutes at an easy pace.

Boot Camp Interval Blast
Mark off six to 15 metres of a straightaway (start short if you haven't laced up your trainers since last summer).

1. Start at one mark and sprint as fast as you can to the next. Jog backwards to the start.

2. Run to the grass and do 25 to 50 crunches.

3. Repeat step one.

4. Run to the grass and do 10 to 20 push-ups.

5. Return to the start and chassé (step with the left foot and hop your right foot forward to catch up with it) for 18 to 45 metres. Immediately grapevine back to the start. (Standing sideways, step with the left foot, cross the right one over it, step out with the left again, and step behind it with the right one.)

6. Walk one lap (400m) around the track.

7. Run up the stadium stairs, taking two at a time for three minutes, then carefully jog down.

8. Walk around the track for three minutes.

9. Repeat the entire circuit.