Detraining in the Older Adult: Effects of Prior Training Intensity on Strength Retention
Chad Harris, Mark DeBeliso, and Bobbie S. Irmischer
Center for Orthopaedic and Biomechanics Research, Department of Kinesiology, Boise State University, Boise, Idaho 83725;
Kent J. Adams
Exercise Physiology Lab, California State University Monterey Bay, Seaside, California 93955;
Terry Ann Spitzer Gibson
Department of Kinesiology, Boise State University, Boise, Idaho 83725
Harris, C., M. DeBeliso, K.J. Adams, B.S. Irmischer, and T.A. Spitzer Gibson. Detraining in the older adult: Effects of prior training intensity on strength retention. J. Strength Cond. Res. 21(3):813–818. 2007.—
In this study, we assessed the influence of training intensity on strength retention and loss incurred during detraining in older adults. In a previous study, untrained seniors (age = 71.0 ± 5.0; n = 61) were randomly divided into 3 exercise groups and 1 control group. Exercise groups trained 2 days per week for 18 weeks with equivalent volumes and acute program variables but intensities of 2 × 15 repetitions maximum (RM), 3 × 9RM, or 4 × 6RM. Thirty of the original training subjects (age 71.5 ± 5.2 years) participated in a 20-week detraining period. A 1RM for 8 exercises was obtained pre- and posttraining and at 6 and 20 weeks of detraining. The total of 1RM for the 8 exercises served as the dependent variable. Analysis of variance procedures demonstrated significant increases in strength with training (44–51%; p < 0.05), but no group effect. All training groups demonstrated significant strength decreases at both 6 and 20 weeks of detraining independent of prior training intensity (all group average 4.5% at 6 weeks and 13.5% at 20 weeks; p < 0.04). However, total-body strength was significantly greater than pretraining values after the detraining period (all group average 82% at 6 weeks and 49% at 20 weeks; p < 0.001).
The results suggest that when older adults participate in progressive resistance exercise for 18 weeks, then stop resistance training (i.e., detrain), strength losses occur at both 6 and 20 weeks of detraining independent of prior resistance training intensity. However, despite the strength losses, significant levels of strength are retained even after 20 weeks of detraining. The results have important implications for resistance-trained older adults who could undergo planned or unplanned training interruptions of up to 5 months.