Reprinted from The Wall Street Journal
By Laura Johannes
The Claim: Dumbbells and barbells have become staples of weight training in part because of their stability. Now, sandbags—which provide a shifting load as the sand moves around inside—are being marketed by several companies as a tool for a more complete workout.
The Verdict: While there’s scant research on the efficacy of sandbag workouts, physical therapists and personal trainers say it makes sense that a bag’s shifting load could help target muscles that may be neglected in traditional weight routines. But they add that the unpredictability of the shifting sand could be dangerous for someone out of shape or with pre-existing injuries.
Josh Henkin, a Scottsdale, Ariz., personal trainer who created an exercise sandbag, says he was inspired by early 20th century strongmen who hoisted a variety of everyday objects. Mr. Henkin said he first tried lifting homemade bags of sand, but when they leaked all over his garage, he formed Innovative Fitness Solutions LLC to improve on the concept.
The Scottsdale company’s Ultimate Sandbag, made of leakproof vinyl with sturdy rubber handles, costs $100 for a version that holds up to 40 pounds of sand, which you must buy separately and add yourself. A $130 bag holds up to 80 pounds. Sandbags, Mr. Henkin says, are better than traditional weights at preparing the body for everyday tasks—such as holding a wriggling baby or lifting an unevenly packed suitcase into an airplane compartment.
Free weights and dumbbells “move in a predictable pattern,” he says, while the weight in the sandbags “move just enough to make the body work to balance and stabilize it.”
Sandbag exercises include many typical workout moves—such as lunges, dead lifts and squats.
So far, there’s no published research on the Ultimate Sandbag, but preliminary results from a 22-person study at the University of Wisconsin, Milwaukee, found significantly increased heart rate when subjects did lunges holding sandbags compared with the same amount of weight in dumbbells, says researcher David Cornell, a doctoral student in the university’s department of kinesiology.
The increased heart rate suggests “higher intensity” probably because the participants had to activate more muscles using the sandbags, adds Mr. Cornell, who co-led the research. Ultimate Sandbags provided equipment for the study, which was presented at a student symposium last year.
Exercising with an unstable load, such as a sandbag, can force you to recruit many muscles in unison—including muscles that don’t always get a workout with predictable loads, says Washington, D.C., physical therapist Robert Gillanders, a spokesman for the American Physical Therapy Association in Alexandria, Va.
For safety reasons, Dr. Gillanders recommends out-of-shape people or those new to weightlifting start training with machines or free weights to build some strength before trying sandbags. Use sandbags to add occasional spice to your workout, he says, and start with half the amount of weight you’d normally use.
I tried out a bright pink Ultimate Sandbag, filled halfway with about 20 pounds of sand from the hardware store and following the enclosed DVD’s instructions. The sandbag exercises were new and fun to me. I particularly enjoyed the rotational lunge, where you swing the bag to one side of your body while lunging backwards. I felt all my muscles were being used, particularly my abdomen. Since several of the exercises challenged muscles I didn’t expect to use, I was glad I started with only half of the weight the sandbag holds.