The most effective and cost-efficient mode of this type of exercise is walking. If you have more time to spend, you can get similar fat-burning benefits of higher intensity cardio. It just takes longer. An hour of walking burns close to the same amount of calories as a 30-minute run. Insulin levels are reduced.
Results are fast.
Endurance is gradually increased. A high percentage of fat vs. carbohydrates is burned. You're more likely to continue working out. Exercise is more enjoyable and sociable. Injuries are avoided.