Suspend any disbelief

Suspension training -- simple, dumbbell-free bodyweight exercises done while pulling on a rope or nylon strap attached to an overhead point -- makes every exercise a total body workout. By adding instability to all strength movements, it blasts the core and other stabilizing muscles, not just the prime movers. This all-body effectiveness makes suspension training popular with sports teams, gym classes and homebodies of all ages and fitness abilities. Adjusting the resistance is easy: Just stand on one foot or change your body angle by moving closer to or farther from the anchor point. Originally hooked to overhead bars and tree limbs, variations on the theme add doorjamb attachments and a pulley.

--

Hanging around

TRX Pro Kit: Invented by former Navy SEAL Randy Hetrick, a pioneer of suspension training, this 9-foot adjustable strap has a handle/foot stirrup on each end, a carabiner in the middle to clip overhead and a padded door anchor.

Likes: A great workout for anybody at any level. Easy to set up and adjust the length with sliding buckles. Includes a very good instructional DVD with a 45-minute, 12-exercise strength-stretching routine featuring squats, sprinter starts, rows, chest presses, delt flies, overhead rollouts, planks, sprinter’s crunches and hip, lateral and torso stretches. In its compact mesh bag, it’s travel-worthy at 2 pounds, 5 ounces.

Dislikes: None, although it lacks the challenging rotation of the CrossCore 180.

Price: $199.95. (888) 878-5348; www.trxtraining .com

Door prize

SKLZ Power Strapz: Two 6-foot-long, 1.5-inch-wide straps with handles and padded harnesses for arms and feet on the ends. Designed for use on a door or doorjamb only.

Likes: Efficient, portable, lightweight (just 1.5 pounds, including nylon carry bag) all-body workout system that gives you most of the effects of the TRX at half the price. A variety of push and pull exercises are possible -- hanging ab crunches, rows, ankle-suspended push-ups, gymnastics-style squat-dips, you name it. The smart, self-contained design has no parts to lose and sets up in seconds. Just drape the two straps over a door, match the built-in numeric anchors and close the door into the frame. Adjust the body-weight load by repositioning the anchors or moving your feet closer to or farther from the door. Putting feet in the strap handles allows some suspension push-ups, plank crunches and other exercises.

Dislikes: None. But being a door-only device, it lacks the true overhead, open-space capability of TRX.

Price: $99.99. (877) 225-7275; www.sklz.com

A twist on training

CrossCore 180 Rotational Bodyweight Training: This design threads a rope through a movable pulley to create “rotational” suspension training, which adds instability and challenge to all movements. Handles/stirrups attach to the rope with carabiners.

Likes: Takes the suspension workout to a new level. The rotating pulley allows for twisting, back-and-forth pull-push motions and single-arm efforts that mimic real movement and magnify instability. Even a simple push-up is much more difficult. Converts to a “regular” suspension trainer by inserting a pin into the pulley to lock the rope in place. A cam buckle strap attaches it to any overhead point and includes a door attachment. A carry bag and DVD are included, though at 4 pounds the system is not as travel-friendly as the rest.

Dislikes: Too industrial to use on a door inside your house -- who wants a 2.5-pound metal pulley banging the wood and scraping the paint? To make it more usable, CrossCore should include a padded jacket for the pulley and a softer door attachment device.

Price: $249.99. (800) 288-3047; www.crosscore-usa .com

Fiscally fit

GoFit Bob Harper Gravity Straps: Budget door suspension trainer.

Likes: All the same great suspension exercises as the Power Strapz at less than half the price. Includes a good-quality training manual and a short, effective DVD featuring Harper. Both adjustable-length straps have their own door anchor, a carabiner, a handle and an ankle/elbow cradle. Weight with the mesh carry bag is 2 pounds, 14 ounces.

Dislikes: Lacks the simpler, quick-change design of the Power Strapz. You’ll spend extra time adjusting the straps, which slows down the workout a bit.

Price: $39.99. (888) 530-4441; www.gofit.net

-- Roy M. Wallack

Wallack is the co-author of “Barefoot Running Step by Step” and “Bike for Life: How to Ride to 100.” roywallack@aol.com