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.

Effects of Resistance Exercise with Instability on Cognitive Function (REI Study): A Proof-Of-Concept Randomized Controlled Trial in Older Adults with Cognitive Complaints.

BACKGROUND: Activities which simultaneously challenge both physical and cognitive function are promising strategies for promoting cognitive function. OBJECTIVE: To examine the effects of resistance exercise with instability and traditional resistance exercise compared with a health education control on cognitive function in older adults with cognitive complaints. METHODS: Sixty-seven participants were randomized to either 12 weeks of thrice-weekly resistance exercise (RE = 23), RE with instability (REI = 22), or a weekly health education control (CON = 22). At each training session, RE and REI participants performed seven exercises for three sets and 10-15 repetitions. REI participants performed each exercise using instability devices. The primary outcome was a composite score of global cognitive function. Secondary outcomes included composite scores for cognitive sub-domains and physical function. RESULTS: Most participants were women (REI: 77%; RE = 78%; CON = 77%; mean age of 71 years), and did not need transport to the intervention site. At completion, compared with CON, REI and RE did not significantly improve on global cognition or each cognitive sub-domain. Both exercise groups improved on the timed up and go (REI - CON: -1.6 s, 95% CI: [-2.6, -0.5]; RE - CON: -1.4 s, 95% CI: [-2.4, -0.5) and 1-RM (REI - CON: 24 kg, 95% CI: [11, 36]; RE - CON: 25 kg, 95% CI: [12, 37]). An exploratory contrast showed that compared with RE, REI promote greater gains on global cognition (2.20, 95% CI: [0.10, 4.31]) and memory (1.34; 95% CI: [0.15, 2.54]). CONCLUSION: REI did not substantially improve cognitive function but did promote physical function among older adults with cognitive complaints. However, compared with RE, REI improved global cognition and memory.

Phase angle is related with inflammatory and oxidative stress biomarkers in older women.

BACKGROUND: The aim of this study was to examine the relation between phase angle (PhA) and inflammatory and oxidative stress biomarkers in older women. METHODS: One hundred and fifty-five physically independent older women participated in this study (67.7±5.7years, 27.0±4.4kg/m2). Inflammatory markers included interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and acute phase reactive protein (CRP). Oxidative stress biomarkers comprised superoxide dismutase (SOD), catalase (CAT), advanced oxidation protein products (AOPP), and total radical-trapping antioxidant potential (TRAP). A spectral bioelectrical impedance device was used to estimate resistance (R) and reactance (Xc) at frequency 50kHz, and subsequently PhA was calculated as arc-tangent (Xc/R)×180°/π. The covariates appendicular lean soft-tissue (ALST), trunk fat mass, and total body fat were determined by whole-body dual-energy X-ray absorptiometry. Linear regression analysis was conducted to further test if PhA is related with the dependent variables, after adjusting for potential covariates. RESULTS: After controlling for the potential covariates (age, trunk fat mass, ALST, and number of diseases) PhA exhibited a significant inverse relation with IL-6 (ß=-0.97; P<0.01), TNF-α (ß=-0.84; P<0.01), and CRP (ß=-0.58; P<0.01). Conversely, PhA was significantly related to CAT (ß=7.27; P<0.01), SOD (ß=10.55; P<0.01) and TRAP (ß=73.08; P<0.01). The AOPP did not demonstrate a significant correlation with PhA (P>0.05). CONCLUSION: Our findings show that PhA is a simple and relevant explanatory variable which is related inflammatory and stress oxidative markers in physically independent older women, regardless of age, number of diseases, and body composition.