Fitness is a lifetime commitment, but you can accelerate results and transform your body in 12 weeks, says Bob Greene, best known as Oprah Winfrey's personal trainer. Not for the "move a little" crowd, this program is intense and challenging, whatever your starting level. "It's a bit like boot camp," Greene acknowledges. You'll do vigorous aerobic exercise 15 (beginning level), 30 (intermediates), or 45 (advanced) minutes 6 days a week, and increase 2 minutes each week--and double your usual minutes for one workout a week. You'll also strength train with dumbbells or machines and do functional training (strengthening stabilizing muscles).
The eating plan is not a diet--rather Greene describes 5 eating rules to help you eat fewer and burn more calories: curb emotional eating, eat breakfast, establish an eating cut-off time, drink lots of water, and limit alcohol. You'll get enough calories to sustain your intense exercise routine, but cut out the calories otherwise stored as fat.

Greene, author of Get With the Program and Make the Connection, also analyzes popular diets, and fills the book with motivational stories of his successful clients. Recommended for those who are ready to commit to an intense program to burn fat, increase metabolism, and change habits for the long haul. --Joan Price