Q. I walk daily holding one-pound dumbbells in each hand so that I can burn more fat and strengthen my upper body muscles, too. But the other day in the park, someone saw me and came up to say that it was bad for my joints. Is this true?
A. Walking with dumbbells is not a good idea even though it seems like a perfectly-efficient mix of cardio for calorie-burning and weight-lifting to tone your muscles. That was the thinking during the 80s when combining cardio with weights in the same workout activity was popular. People flung their arms around holding dumbbells while they danced in aerobics or step classes. Walkers were often seen pumping their way along the sidewalk holding weights known as Heavy Hands.
If you were to gauge whether this workout is effective by how it feels, you might think it's a good move: Swinging a light weight while you sweat through your cardio workout feels tough. Your arms burn and get tired. The whole exercise session feels harder.
But like many exercise techniques that bring on a muscle burn—such as the burn from the isometric moves of some Lotte Berk exercises or from multiple repetitions of ab crunches—that burn can be deceiving. It’s often not providing the benefit that most people assume it is and can be risky to joints. (I’ve written about the deceptive exercise burn in other columns here and here).
Several factors make a difference when assessing how effective swinging hand weights during a cardio workout is:
Does it enhance the workout you are adding the weights to? And if so, does it lead to injuries, making the risk outweigh any benefit you may get?
The goal for cardio is usually to bump up the calorie burn to decrease body fat and lose weight faster. Studies show that holding one-pound dumbbells during a cardio workout do not increase the calorie burn. So if you are walking at a 3.5 mph pace and burning 5 calories per minute--adding a hand or ankle weight may make it feel harder, but you aren't actually burning more calories. A 2002 study in the Journal of Sports Medicine and Physical Fitness found no added benefit from wearing both ankle weights and holding hand weights at the same time! They compared 32 women who wore 1.5-pound ankle weights and held 3-pound hand weights while doing 50 minutes of step aerobics three times a week, with women who stepped using no weights. All the women improved their body composition, decreasing body fat and increasing lean body mass slightly. But the weights didn’t enhance the effect even though the workout felt harder!
Well known exercise physiologist, Len Kravitz, PhD, at the University of New Mexico conducted a study published in 1997 in the Journal of Strength and Conditioning Research. He compared the long term effects of women who did step aerobics while holding hand weights that started at around 2 pounds and worked up to 4 pounds over a 12 week period. The women did a 30-minute step workout three days a week. At the end of the training period the women in both groups improved their fitness levels and decreased their body fat percentage. But the women who stepped while lifting weights did not get better results, suggesting that it was the step workout--not the hand weights--that produced the improved fitness effects.
A slightly increased calorie burn can be experienced from holding heavier weights, such as three or five pound dumbbells. The problem with this is that when you swing a weight, you exponentially increase the forces on the joints, so what would be considered a very light weight if you were doing 12 slow and controlled repetitions of biceps curls suddenly becomes a magnified stress on the joints. Shoulder and elbows get strained using hand weights, and knees and hips get strained using ankle weights.
Once you start swinging a weight, you want to make sure that you don't drop it. Chances are your grip will be tight, and squeezing a weight can increase blood pressure.
Researchers writing in a 2007 study in the Journal of Education and Human Development noted that not only can adding external weight to wrists, hands and/or ankles increase the risk of injuries, hand weights can result in an abnormal rise in blood pressure.
Wearing a weight vest is usually considered a safer approach than hand or ankle weights. There are different styles of vests but generally they have weight inserts that allow you to make the vest heavier or lighter. Vests can range from, say, five or 10 pounds to 20 or more. They are safer because the weight is strapped to your torso, so your swinging limbs don't transmit force to the joints. But, are they effective?
A 2007 study (above) tested college-aged women wearing a weighted vest that was 10% more than their body weight (15 pounds or so). They walked at 4 miles per hour on a treadmill at different inclines and showed no added fitness benefits compared to walking without the weighted vest. Wearing 20% more than their body weight (30 pounds or so) improved fitness more than not wearing the vest, however. The calorie-burn was not measured in this study, but super-heavy vests will burn more calories. While low impact activities such as stepping and walking would be safe for most people while wearing a weight-vest, running or high impact aerobics would probably be too stressful for most people since added weight will increase the impact forces on the joints upon landing.
But what about strengthening the arms? Lifting very light weights is not the recipe for getting stronger and firmer. You're better off spending 20 minutes at least once a week using heavier weights doing a set of exercises that target all your major muscle groups.
So why do the arms feel so worked when you do cardio while holding hand-weights? It's simply muscle fatigue. Back in the 80s, everyone did the Jane Fonda arm circles (arms held straight out to the sides at shoulder level while performing multiple small circular motions). This exercise created a deceptive muscle burn that didn't do much for strength or firmness. At best, this is the recipe for increased muscle endurance.
In general, using light hand or ankle weights is not going to result in any added benefit for weight loss or muscle strength and firmness. Using them may increase the risk of stress to the surrounding joints. So, ditch the dumbbells and increase the calorie burn of your walking in other ways: walk faster, insert jogging intervals or walk up hills.
