Will Short-term Aerobic Exercise Help Osteoporotic Women with Balance?

The article “Effects of short-term aerobic exercise with and without external loading on bone metabolism and balance in postmenopausal women with osteoporosis” was published online (on March 24, 2012); it will appear in print in the journal Rheumatology International.  It publishes the results from a bone health study run in Iran.

In the study, researchers specifically examined how submaximal aerobic exercise affects bone metabolism and balance.  They considered aerobic exercise done with and without a weighted vest (as the external loading).  The study was done on postmenopausal women who have osteoporosis.

Thirty-six sedentary, postmenopausal women participated in the study (all joined voluntarily).  They were randomized into 3 groups:  aerobic exercise, aerobic exercise with weighted vest, and control.

The study was done over 6 weeks, and in that time, the aerobic exercise groups did 18 sessions (30 minutes daily, 3 times/week) of submaximal treadmill walking.  The weighted vest group wore the vest during this exercise period, and it was 4% to 8% of the woman’s body weight.  During the same 6 weeks, the control group did no aerobic exercise.

To gauge changes in bone metabolism and balance, the researchers looked at several measurements before and after the 6 weeks.  They measured:

• Body composition
• Bone biomarkers
• Bone-specific alkaline phosphatase (BALP)
• N-terminal telopeptide of type 1 collagen (NTC)
• Balance:  Near Tandem Stand (NTS) and Star-excursion (SE)

After the 6 weeks, several changes were seen in the aerobic exercise groups.

In the weighted-vest group, 2 measurements changed significantly:  fat decreased (p = 0.01) and fat-free mass increased (p = 0.005).

In both the aerobic exercise group and the aerobic exercise with weighted vest group, there was a significant increase in BALP (p ≤ 0.05).  Those groups also saw a significant decrease in NTX (p ≤ 0.05).

Looking at the effects of submaximal aerobic exercise on balance, the NTS results varied in the 2 aerobic exercise groups and the control group.  In the groups that exercised, NTS increased (aerobic exercise group:  + 49.68%; aerobic exercise with weighted vest group: + 104.66%).  However, NTS decreased in the control group (-28.96%).

An additional benefit of aerobic exercise with a weighted vest was seen in EW values; there was a significant increase (in all directions) in the weighted-vest group.         

This study suggests that submaximal aerobic exercise done by postmenopausal women with osteoporosis can promote bone synthesis and decrease bone resorption.  Plus, if a weighted vest is worn during exercise, the woman can experience an improvement in balance.