. "Interval workouts burn calories like lighter fluid," says Vindum. Head to a park, the playground or even the beach to do the workouts, and experiment with running on various surfaces (sand, grass, earth). Running outside, building strength and blasting

miles in my last race. In 11 years, I had run 603 races, an average of 55 a year. In that time I had only one short period when injury stopped me from training regularly. This owes something, I think, to training a lot on grass and sand, and to running

wearing a belt and pulling against a resistance. Like weight training, this has the advantage of being quantifiable, so you can see your progress. You can measure the load, the number of repetitions and the speed of the runs.Hill running and sand