How much exercise do I really need to lose weight?

Make your health a priority and carve out four to five days every week for your workouts. If you want to reprogram your metabolism, you have to stabilize your blood sugar and optimize your exercise.

Try doing 30-second sprints [on the treadmill] with a one- to two-minute recovery for a total of 30 minutes. Then in the same session, add 15-30 minutes of steady-state cardio. Do that at least two to three times per week. On your other days, do some kind of strength training for 30-60 minutes--like Pilates, yoga or weight training.

If you're only doing steady-state cardio (like jogging on a treadmill at the same speed for 30 minutes), then you're only using 50% of your muscle. You must use the red (fat-burning) and the white (high-intensity training) muscle. Diversify your exercise to maximize fat burning.

Source: Mark MacDonald