Effect of 16-Weeks of Strength Training on Functionality and Body Composition of Older Adults.

The effect of different types of contractions (eccentric/concentric) has gained attention in the last years, where it was suggested that eccentric training would promote better results regarding the muscle mass development, affecting the functionality of older adults PURPOSE: Analyze the effect of 16-weeks of eccentric and concentric training on functionality and body composition of older adults. METHODS: Sixteen-weeks of strength training with an emphasis on concentric/eccentric contractions were applied in 35 older adults, which were randomized into three groups: Eccentric Training N=12 (ET); Concentric Training N=12 (CT) and Control Group = 11 (CG). Functionality was analyzed through the timed up and go test (TUG), 30-second chair test, and handgrip strength. Body composition was accessed through the amount of lean body mass (LBM) and body fat (%BF), analyzed with a Bioelectrical Impedance Analysis (BIA). Muscle thickness of biceps brachialis (BTH) and femoris rectus (FRTH) were accessed with an ultrasound (Eco III CHSON). All the analyses were made at the beginning of the intervention and after 16-weeks of the training protocol. RESULTS: TUG was significantly lower in ET and CT compared to CG after 16 weeks of strength training (13.6 ± 0.7 to 17.02 ± 0.7 and 13.8 ± 0.6 to 17.02 ± 0.7 with p=0.001) without significant difference between intervention groups. The 30-second chair test was significantly higher in ET and CT compared to CG (11.9 ± 0.73 to 6.1 ± 0.71 with p= 0.001 and 10.9 ± 0.64 to 6.1 ± 0.71 with p=0.01 respectively). Hand Grip was statistically better in ET and CT compared to CG (21.5 ± 0.50 to 17.2 ± 0.5 with p= 0.001 and 21.4 ± 0.46 to 17.2 ± 0.5 with p=0.002). The %BF reductions were 6% higher in ET compared to CT and 19% higher compared to CG. BTH was significantly higher in ET compared to CG (0.46 ± 0.143 cm to 0.08 ± 0.137 with p=0.001) without differences between ET and CT. FRTH was significantly higher at the end of 16 weeks in ET and CT compared to the pre-test (2.40 ± 0.2 to 2.67 ± 0.19 cm with p=0.001 and 2.35 ± 0.193 to 2.61 ± 0.1 cm with p=0.05), with the control group presenting a significant decrease (2.58 ± 0.19 cm to 2.36 ± 0.18 cm with p=0.001) CONCLUSIONS: Both ET and CT promote improvements in the functionality and the body composition of older adults; however, no statistical change was observed between ET/CT groups.