Q:I TAKE a class at my local gym where dumbbells were
used. Now I hear the class may switch to flexible bands. Theweights have significantly improved my bone density over the pasttwo years. What is the difference between weightlifting withdumbbells and resistance bands? Will I get the same benefit?
A: The single most effective way to maintain bone health isthrough weightifting. According to Tufts University professor andauthor Miriam Nelson, 'We found that women who did resistancetraining twice a week for one year actually gained bone density,(compared to) a control group who did no resistance training andlost bone density.'
As for why this is the case, leading tissue researcher, KennethMcLeod, chairman of the Bioengineering Department at Binghamton(N.Y.) University, found, 'There has to be a signal to make bone,and it turns out that if you don't have adequate fluid flow acrossyour bone, you're not going to have adequate cell metabolism totrigger cell formation.'
He has found that the key to triggering bone growth is to focusprimarily on a specific kind of Type II muscle fiber called TypeIIA. This fiber responds to both endurance and explosive movements,which mean a variety of weight lifting methods may be the key tobone stimulation.
Dumbbells are the most recommended because, according to Nelson,'They offer greater and more standardized intensity.' In otherwords, it is easier to progressively push yourself to use heavierweights because their pound-for-pound resistance is known. Bandswill yield similar benefits when it comes
to improving bone density, but you will have to focus on pushingyourself because the 'weight' varies with the tension and forceapplied to the band.
If your instructor makes sure the class keeps up the intensity,you should be just fine.
In March 2005, the University of Connecticut Health Centerreleased a study involving resistance training with 189 womenbetween the ages of 59 and 78. They engaged in moderate resistancetraining of either the lower or upper body. The lower bodyexercisers used weighted belts; the upper body exercisers usedelastic bands and dumbbells.
'Our original hypothesis was that femoral bone density would beincreased with the lower-body exercises,' said principalinvestigator James O. Judge, M.D., Professor of Medicine at theUniversity of Connecticut Health Center.
'However, our results showed there was no difference overallbetween the two training programs -- both were beneficial.'
In other words, resistance training in all forms is good for yourbones and, at least in the Connecticut study, it did not seem tomatter whether you focused on upper- or lower-body exercise orwhether you used weights or bands -- all produced good results forthe bones in general.
The other good news is equipment costs for a bone preservationexercise program are minimal and the exercising can be done in thehome. Dumbbells and resistance bands are inexpensive and areavailable at many retail stores.
Also, impact exercise should be included in any bone lossprevention program, particularly among pre-menopausal women. Thiswould include aerobics, kickboxing, jumping rope, snowshoeing,running, tennis and power walking. (Note that cycling and swimmingare not considered weight-bearing.)
The most practical for the majority of post-menopausal women iswalking, so it is advised that this also be part of your bonedensity program.
Linda Buch is a certified personal trainer. She will answerfitness questions in Body Language, but not individually. Sendquestions to Body Language, Bay Area Living, 4770 Willow Road,Pleasanton, CA 94588 or e-mail linda@ljbalance.com.
