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We sought to determine the effects of 12 months of power training on cognition, and whether improvements in body composition, muscle strength, and/or aerobic capacity (VO2peak) were associated with improvements in cognition in older adults with type 2 diabetes (T2D). Participants with T2D were randomized to power training or low-intensity sham exercise control condition, 3 days per week for 12 months. Cognitive outcomes included memory, attention/speed, executive function, and global cognition. Other relevant outcomes included VO2peak, strength, and whole body and regional body composition. One hundred and three adults with T2D (mean age 67.9 years; standard deviation [SD] 5.9; 50.5% women) were enrolled and analyzed. Unexpectedly, there was a nearly significant improvement in global cognition (p = .05) in the sham group relative to power training, although both groups improved over time (p < .01). There were significant interactions between group allocation and body composition or muscle strength in the models predicting cognitive changes. Therefore, after stratifying by group allocation, improvements in immediate memory were associated with increases in relative skeletal muscle mass (r = 0.38, p = .03), reductions in relative body fat (r = -0.40, p = .02), and increases in knee extension strength were directly related to changes in executive function (r = -0.41, p = .02) within the power training group. None of these relationships were present in the sham group (p > .05). Although power training did not significantly improve cognition compared to low-intensity exercise control, improvements in cognitive function in older adults were associated with hypothesized improvements in body composition and strength after power training. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes (T2D) is projected to affect 439 million people by 2030. Medical management focuses on controlling blood glucose levels pharmacologically in a disease that is closely related to lifestyle factors such as diet and inactivity. Physical activity guidelines include aerobic exercise at intensities or volumes potentially unreachable for older adults limited by many co-morbidities. We aim to show for the first time the efficacy of a novel exercise modality, power training (high-velocity, high-intensity progressive resistance training or PRT), in older adults with T2D as a means for improving glycemic control and targeting many associated metabolic and physiological outcomes. Eligibility criteria included community-dwelling men and women previously diagnosed with T2D who met the current definition of metabolic syndrome according to the International Diabetes Federation. Participants were randomized to a fully supervised power training intervention or sham exercise control group for 12 months. Intervention group participants performed whole body machine-based power training at 80%1RM, 3 days per week. The control group undertook the same volume of non-progressive, low-intensity training. Participants were assessed at baseline, 6 months and 12 months and followed for a further 5 years, during which time participants were advised to exercise at moderate-high intensity. Glycemic control (HbA1c) and insulin resistance as measured by the homeostatic model assessment 2 (HOMA2-IR) were the primary outcomes of the trial. Outcome assessors were blinded to group assignment and participants were blinded to the investigators' hypothesis regarding the most effective intervention.Results: We recruited 103 participants (48.5 % women, 71.6 ± 5.6 years). Participants had 5.1 ± 1.8 chronic diseases, had been diagnosed with T2D for 8 ± 6 years and had a body mass index (BMI) of 31.6 ± 4.0 kg/m(2). Fasting glucose and insulin were 7.3 ± 2.4 mmol/L and 10.6 ± 6.3 mU/L, respectively. HbA1c was 54 ± 12 mmol/mol. Eighty-six participants completed the 12-month assessment and follow-up is ongoing. This cohort had a lower-than-expected dropout (n = 14, 14 %) over the 12-month intervention period.Conclusions: Power training may be a feasible adjunctive therapy for improving glycemic control for the growing epidemic of T2D in older adults.Trial Registration: Australian and New Zealand Clinical Trials Registry ACTRN12606000436572 (24 September 2006). [ABSTRACT FROM AUTHOR]

OBJECTIVE--To investigate changes in body composition after 12 months of high-intensity progressive resistance training (PRT) in relation to changes in insulin resistance (IR) or glucose homeostasis in older adults with type 2 diabetes. RESEARCH DESIGN AND METHODS--One-hundred three participants were randomized to receive either PRT or sham exercise 3 days per week for 12 months. Homeostasis model assessment 2 of insulin resistance (HOMA2-IR) and glycosylated hemoglobin (HbA1c) were used as indices of IR and glucose homeostasis. Skeletal muscle mass (SkMM) and total fat mass were assessed using bioelectrical impedance. Visceral adipose tissue, mid-thigh cross-sectional area, and mid-thigh muscle attenuation were quantified using computed tomography. RESULTS--Within the PRT group, changes in HOMA2-IR were associated with changes in SkMM (r = 20.38; P = 0.04) and fat mass (r = 0.42; P = 0.02). Changes in visceral adipose tissue tended to be related to changes in HOMA2-IR (r = 0.35; P = 0.07). Changes in HbA1c were related to changes in mid-thigh muscle attenuation (r = 0.52; P = 0.001). None of these relationships were present in the sham group (P > 0.05). Using ANCOVA models, participants in the PRT group who had increased SkMM had decreased HOMA2-IR (P = 0.05) and HbA1c (P = 0.09) compared with those in the PRT group who lost SkMM. Increases in SkMM in the PRT group decreased HOMA2-IR (P = 0.07) and HbA1c (P < 0.05) compared with those who had increased SkMM in the sham group. CONCLUSIONS--Improvements in metabolic health in older adults with type 2 diabetes were mediated through improvements in body composition only if they were achieved through high-intensity PRT. [ABSTRACT FROM AUTHOR]