[ottsville]

Notfree: most people are not in any type of condition to train at a high intensity, especially if they are just starting a regimen. The average person won't and shouldn't jump off the couch and say "I need to lose weight so I'm going to run as far as I can at max speed." Many won't after long periods of base training either. That type of workout will not keep the interest of 99% of the people who are trying to lose weight in addition to the increased risk of injury. I believe that most people workout at intensities that may not optimize their weight loss, but at intensities that will keep them interested.

Fitness described some basics, but there are lots of new studies in this area. Some recent studies are now showing that interval type workouts are more efficient at burning fat than either a lower/higher intensity. From what I've read though, there seems to be a lot that is specific to the person/situation.

One thing that has helped me to get more of a grasp on workout stuff like this is to understand some basic nutrition and chemistry of fueling muscles. I would do some research on glycogen stores, lactate threshold, anaerobic threshold, nutrition for athletes, and recovery meals for starters.