Premise: P90X started the trend. Now, the workout takes it one step further with the new P90X2. The training is the same as the original – you tirelessly exhaust your body rotating through 12 different daily hour-long workouts over 90 days in the hope of getting ripped and lean – but the new version has a whole new set of pain-inducing sweat. Using a mixture of intense exercises, including explosive plyometric drills, the system is divided into three, 30-day phases to help your body adjust to the plan. But you'll feel the intensity of this right from Day One.

Pros: You can do the program with little more than a few pairs of dumbbells (or resistance bands) and a pull-up bar. It also allows you to buy two booster packs (the Deluxe and Ultimate) that let you add more equipment and workouts to further raise the intensity.

Problems: Some of the moves require a higher degree of balance and coordination, so if you lack either, it might be difficult to complete without having to stop periodically.

Perfect for: Anyone that may benefit from better overall stability in their sport, or, those looking to challenge themselves beyond the average weight-training circuit. [$119.85; P90X2.com]