Objetive The aim of this study was to evaluate the effects of a physical activity (PA) program and subsequent detraining on the contractile capacity of the Vastus Lateralis (VL) and Biceps Femoris (BF) in patients diagnosed with Alzheimer's Disease (AD).

Methods A total of 37 subjects were divided in: the intervention group (IG) consisted of 19 subjects (75.58 years ±6.18) and the control group (CG) for 18 subjects (79.92 years ±7.03). The PA intervention program was 4 month length, 60 training sessions and 5 days/week. The Tensiomyography (TMG) was used to assess the maximum radial displacement of the muscle belly (Dm) and the normalized response velocity (Vrn) in VL and BF of both legs. The assessment was performed before intervention (Pre), at the end of four months of intervention (Post) and two months after finishing the intervention (Post 2).

Results Vrn for VL in IG increased in both legs after the intervention program (p≤0.05) while later decreased in the post2 (p≤0.05). Although we observe an increase of Vrn in CG (p≤0.05) it was not significantly higher than baseline levels (pre). The BF shows the same trend than VL for Vrn in IG, whereas in CG there is a tendency to maintain values. Dm for VL shows a decrease in post and an increased in post 2 assessment in IG. Dm values for left BF show significant differences in IG whereas in CG there is a tendency to maintain values. Dm for VL in IG decrease in both legs in post assessment (p≤0.05), and increases in post2 (p≤0.05). However, Dm showed only significant increases in right VL post assessment compared to baseline.

Conclusions A PA program adapted to elderly diagnosed with AD, produces changes in morphology and muscle responses. Further, it enhances balance and motor skills, which results in a reduction in the risk of falls, improves the quality of life, and return to baseline values.