Eight Weeks of Resistance Training Is Not a Sufficient Stimulus to Improve Body Composition in Post-COVID-19 Elderly Adults

Abstract

Background: This study sought to assess how body mass (BM) and body composition in post-COVID-19 elderly adults were affected by 8 weeks of resistance training. An additional goal was to determine the agreement between Bioelectrical Impedance Analysis (BIA) and Dual Energy X-Ray Absorptiometry (DXA) in elderly people. Methods: Participants were randomly assigned to an intervention Group, which engaged in 8 weeks of resistance training, and a Control Group, which was advised to maintain their usual activity levels. Before and after the intervention, the body composition was analyzed via the BIA and DXA methods. Results: We found no statistically significant changes in BM or body composition following resistance training. BIA was found to overestimate the participants' baseline BM and fat-free mass (FFM) and to underestimate the fat mass (FM), compared to the DXA method. There were no significant differences in intervention-induced changes in FM and FFM measured by BIA and DXA. Conclusions: Moderate intensity resistance training lasting 8 weeks was not found to be a sufficient stimulus to improve BM and body composition in post-COVID-19 elderly adults. We also conclude that BIA may serve as a viable alternative to DXA for measuring longitudinal changes in body composition in elderly people.

Keywords: BIA; COVID-19; DXA; body composition; older adults; physical activity; resistance training.

Figure 1

CONSORT flow diagram. F—females; M—males.

Figure 2

Bland–Altman plots comparing body mass (BM) (A), fat mass (FM) (B), and fat-free mass (FFM) (C) determined by DXA and BIA methods at baseline. The solid line represents the bias, and the dashed lines represent upper and lower limits of agreement (LOA = Bias ± 1.96 × SD). BIA—Bioelectrical Impedance Analysis; DXA—Dual Energy X-Ray Absorptiometry.