Can Albuterol Help Resistance Exercise Attenuate Unloading-Induced Bone Loss?

Caruso, J.F., J.L. Hamill, M. Yamauchi, T.D. Cook, D.R. Mercado, G. Gibb, B.K. Higginson, J. Elias, and D.A. Hernandez. Can albuterol help resistance exercise attenuate unloading-induced bone loss? J. Strength Cond. Res. 18(4):000-000. 2004.-Hind-limb-suspended rats incur attenuated bone loss with beta sub(2)-agonists, and humans note similar changes with concurrent resistance exercise. To examine if the beta sub(2)-agonist albuterol helps resistance exercise reduce unloading-induced bone loss, human subjects performed 40 days of unilateral limb suspension with their left legs, otherwise refraining from normal ambulatory activity. While performing left leg strength training 3 days.week super(-1), subjects received a concurrent placebo or albuterol (16 mg.day super(-1)) treatment. Left leg muscle and bone changes were analyzed with 2 x 2 analyses of covariance (ANCOVAs). Mechanical loading values were calculated from workouts and compared using a 2 x 5 analysis of variance (ANOVA) and a Tukey post hoc test. The resistance exercise-albuterol assignment evoked significant (p < 0.05) left leg bone mineral content (BMC) gains (+2.24%) after 40 days. During the final unloading days, the resistance exercise-placebo group's mechanical loading data declined (-13.91%) significantly (p < 0.05) versus initial values. A resistance exercise-albuterol assignment likely increased BMC by maintaining the mechanical loading stimulus.