Resistance Training with Instability Does Not Hamper Total Training Volume and Muscle Strength Gains in Older Adults: a Secondary Analysis from REI Study.

Background: Resistance training with instability (REI) emerged as a promising training modality for older adults aiming to counteract age-related changes. Objectives: We compared the effects of 12 weeks of REI and traditional resistance exercise (RE) on muscle strength in older adults with cognitive impairment. We further explored if total training volume (TTV) significantly differs among training groups. Methods: This is a secondary analysis of the REI study. Participants were randomly assigned to REI (n=22) or RE (n=23). RE protocol involved moderate-intensity, free-weight, and machines-based resistance exercises (3 sets, 10-15 repetitions). REI received a similar training protocol, in which exercises were simultaneously performed with instability/unstable devices (e.g., squat exercise under a foam pad or Bosu® ball). Maximal isometric strength and isokinetic parameters were assessed at baseline and after completion of a 12-week intervention through a hydraulic handgrip and isokinetic dynamometer, respectively. TTV (sets × repetitions × load) was computed based on external training load over the 12 weeks. Results: No differences were observed between groups (p=.35) after the intervention. Over 12 weeks, REI and RE improved isometric handgrip strength (p<.001) and isokinetic performance (p=.04). We also did not find differences in the TTV between training groups (p=.28). Conclusion: We demonstrated that both REI and RE training induced similar gains in muscle strength. Combining unstable surfaces/instability devices did not hamper TTV, which may have clinical applications in the context of exercise for older adults.

Association between physical functioning with cognition among community-dwelling older adults: a cross-sectional study / Associação entre função física e cognição em idosos da comunidade: estudo transversal

OBJECTIVE: Declines in physical and cognitive functioning often co-exist through aging. Gait-related parameters have been related to cognitive function, although it is unclear whether other measures of physical functioning are similarly related to cognition. Here, we analyzed the relationship between physical functioning with cognition in older adults. METHODS: In total, baseline data of 116 dementia-free older adults recruited from two separated clinical trials (RCT) were included (M age = 69 years, SD = 6; 71% women). We quantified cognitive functioning using the Montreal Cognitive Assessment (MoCA) and executive functioning tasks (Digit Span Forward minus Backward and verbal fluency ­ FAS and animal naming). Physical function measures included gait speed, Short-physical Performance Battery (SPPB), five-times Sit-to-Stand Test, the Timed Up and Go (TUG) test, the Six-minute Walk Test (6MWT), and lower extremity muscle strength. We used multiple linear regression analyses to explore the association between cognitive measures and each measure of physical functioning, adjusting for age, sex, education, and RCT. Regression coeficients (b), standard error (SE) and 95% confidence intervals (CI) were used to summarize main results. RESULTS: We observed a positive association between muscle strength and the MoCA (b = 0.84, SE = 0.40, 95%CI 0.05­1.64) after controlling for covariates. Significant associations were also found between the five-times-sit-to-stand test (b = -0.63, SE = 0.26, 95%CI -1.15­-0.12), TUG (b = -1.13, SE = 0.57, 95%CI -2.26­-0.01), 6MWT (b = 0.04, SE = 0.02, 95%CI 0.01­0.07), and lower extremity muscle strength (b = 1.92, SE = 0.93, 95%CI 0.09­3.77) with the FAS verbal fluency test, and between the TUG (b = -0.62, SE = 0.24, 95%CI -1.11­-0.14) with animal naming. CONCLUSION: In community-dwelling older adults, higher levels of muscle strength, dynamic balance and cardiorespiratory fitness were positively related with global cognition and executive control measures.