Yorgi Mavros

Changes in insulin resistance and HbA1c are related to exercise-mediated changes in body composition in older adults with type 2 diabetes: interim outcomes from the GREAT2DO trial.

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 = −0.38; 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.

Mediation of Cognitive Function Improvements by Strength Gains After Resistance Training in Older Adults with Mild Cognitive Impairment: Outcomes of the Study of Mental and Resistance Training

To determine whether improvements in aerobic capacity (VO2peak) and strength after progressive resistance training (PRT) mediate improvements in cognitive function.

Exercise for Individuals with Lewy Body Dementia: A Systematic Review

Background Individuals with Lewy body Dementia (LBD), which encompasses both Parkinson disease dementia (PDD) and Dementia with Lewy Bodies (DLB) experience functional decline through Parkinsonism and sedentariness exacerbated by motor, psychiatric and cognitive symptoms. Exercise may improve functional outcomes in Parkinson’s disease (PD), and Alzheimer’s disease (AD). However, the multi-domain nature of the LBD cluster of symptoms (physical, cognitive, psychiatric, autonomic) results in vulnerable individuals often being excluded from exercise studies evaluating physical function in PD or cognitive function in dementia to avoid confounding results. This review evaluated existing literature reporting the effects of exercise interventions or physical activity (PA) exposure on cluster symptoms in LBD. Methods A high-sensitivity search was executed across 19 databases. Full-length articles of any language and quality, published or unpublished, that analysed effects of isolated exercise/physical activity on indicative Dementia with Lewy Bodies or PD-dementia cohorts were evaluated for outcomes inclusive of physical, cognitive, psychiatric, physiological and quality of life measures. The protocol for this review (Reg. #: CRD42015019002) is accessible at http://www.crd.york.ac.uk/PROSPERO/. Results 111,485 articles were initially retrieved; 288 full articles were reviewed and 89.6% subsequently deemed ineligible due to exclusion of participants with co-existence of dementia and Parkinsonism. Five studies (1 uncontrolled trial, 1 randomized controlled trial and 3 case reports) evaluating 16 participants were included. Interventions were diverse and outcome homogeneity was low. Habitual gait speed outcomes were measured in 13 participants and increased (0.18m/s, 95% CI -0.02, 0.38m/s), exceeding moderate important change (0.14m/s) for PD cohorts. Other outcomes appeared to improve modestly in most participants. Discussion Scarce research investigating exercise in LBD exists. This review confirms exercise studies in PD and dementia consistently exclude LBD participants. Results in this cohort must be treated with caution until robustly designed, larger studies are commissioned to explore exercise efficacy, feasibility and clinical relevance.

Does Strength-Promoting Exercise Confer Unique Health Benefits? A Pooled Analysis of Data on 11 Population Cohorts With All-Cause, Cancer, and Cardiovascular Mortality Endpoints

Abstract Public health guidance includes recommendations to engage in strength‐promoting exercise (SPE), but there is little evidence on its links with mortality. Using data from the Health Survey for England and the Scottish Health Survey from 1994‐2008, we examined the associations between SPE (gym‐based and own‐body‐weight strength activities) and all‐cause, cancer, and cardiovascular disease mortality. Multivariable‐adjusted Cox regression was used to examine the associations between SPE (any, low‐/high‐volume, and adherence to the SPE guideline (≥2 sessions/week)) and mortality. The core sample comprised 80,306 adults aged ≥30 years, corresponding to 5,763 any‐cause deaths (736,463 person‐years). Following exclusions for prevalent disease/events occurring in the first 24 months, participation in any SPE was favorably associated with all‐cause (hazard ratio (HR) = 0.77, 95% confidence interval (CI): 0.69, 0.87) and cancer (HR = 0.69, 95% CI: 0.56, 0.86) mortality. Adhering only to the SPE guideline was associated with all‐cause (HR = 0.79, 95% CI: 0.66, 0.94) and cancer (HR = 0.66, 95% CI: 0.48, 0.92) mortality; adhering only to the aerobic activity guideline (equivalent to 150 minutes/week of moderate‐intensity activity) was associated with all‐cause (HR = 0.84, 95% CI: 0.78, 0.90) and cardiovascular disease (HR = 0.78, 95% CI: 0.68, 0.90) mortality. Adherence to both guidelines was associated with all‐cause (HR = 0.71, 95% CI: 0.57, 0.87) and cancer (HR = 0.70, 95% CI: 0.50, 0.98) mortality. Our results support promoting adherence to the strength exercise guidelines over and above the generic physical activity targets.

Effects of a Modified German Volume Training Program on Muscular Hypertrophy and Strength.

Abstract Amirthalingam, T, Mavros, Y, Wilson, GC, Clarke, JL, Mitchell, L, and Hackett, DA. Effects of a modified German volume training program on muscular hypertrophy and strength. J Strength Cond Res 31(11): 3109–3119, 2017—German Volume Training (GVT), or the 10 sets method, has been used for decades by weightlifters to increase muscle mass. To date, no study has directly examined the training adaptations after GVT. The purpose of this study was to investigate the effect of a modified GVT intervention on muscular hypertrophy and strength. Nineteen healthy men were randomly assign to 6 weeks of 10 or 5 sets of 10 repetitions for specific compound resistance exercises included in a split routine performed 3 times per week. Total and regional lean body mass, muscle thickness, and muscle strength were measured before and after the training program. Across groups, there were significant increases in lean body mass measures, however, greater increases in trunk (p = 0.043; effect size [ES] = −0.21) and arm (p = 0.083; ES = −0.25) lean body mass favored the 5-SET group. No significant increases were found for leg lean body mass or measures of muscle thickness across groups. Significant increases were found across groups for muscular strength, with greater increases in the 5-SET group for bench press (p = 0.014; ES = −0.43) and lat pull-down (p = 0.003; ES = −0.54). It seems that the modified GVT program is no more effective than performing 5 sets per exercise for increasing muscle hypertrophy and strength. To maximize hypertrophic training effects, it is recommended that 4–6 sets per exercise be performed, as it seems gains will plateau beyond this set range and may even regress due to overtraining.

The effect of resistance exercise on sleep: A systematic review of randomized controlled trials

Impaired sleep quality and quantity are associated with future morbidity and mortality. Exercise may be an effective non-pharmacological intervention to improve sleep, however, little is known on the effect of resistance exercise. Thus, we performed a systematic review of the literature to determine the acute and chronic effects of resistance exercise on sleep quantity and quality. Thirteen studies were included. Chronic resistance exercise improves all aspects of sleep, with the greatest benefit for sleep quality. These benefits of isolated resistance exercise are attenuated when resistance exercise is combined with aerobic exercise and compared to aerobic exercise alone. However, the acute effects of resistance exercise on sleep remain poorly studied and inconsistent. In addition to the sleep benefits, resistance exercise training improves anxiety and depression. These results suggest that resistance exercise may be an effective intervention to improve sleep quality. Further research is needed to better understand the effects of acute resistance exercise on sleep, the physiological mechanisms underlying changes in sleep, the changes in sleep architecture with chronic resistance exercise, as well its efficacy in clinical cohorts who commonly experience sleep disturbance. Future studies should also examine time-of-day and dose-response effects to determine the optimal exercise prescription for sleep benefits.

The effect of progressive resistance training on aerobic fitness and strength in adults with coronary heart disease: A systematic review and meta-analysis of randomised controlled trials:

Design We aimed to evaluate the effect of progressive resistance training on cardiorespiratory fitness and muscular strength in coronary heart disease, when compared to control or aerobic training, and when combined with aerobic training. Secondary aims were to evaluate the safety and efficacy of progressive resistance training on other physiological and clinical outcomes. Methods and results Electronic databases were searched from inception until July 2016. Designs included progressive resistance training vs control, progressive resistance training vs aerobic training, and combined training vs aerobic training. From 268,778 titles, 34 studies were included (1940 participants; 71.9% male; age 60 ± 7 years). Progressive resistance training was more effective than control for lower (standardized mean difference 0.57, 95% confidence interval (0.17–0.96)) and upper (1.43 (0.73–2.13)) body strength. Aerobic fitness improved similarly after progressive resistance training (16.9%) or aerobic training (21.0%); (standardized mean difference –0.13, 95% confidence interval (–0.35–0.08)). Combined training was more effective than aerobic training for aerobic fitness (0.21 (0.09–0.34), lower (0.62 (0.32–0.92)) and upper (0.51 (0.27–0.74)) body strength. Twenty studies reported adverse event information, with five reporting 64 cardiovascular complications, 63 during aerobic training. Conclusion Isolated progressive resistance training resulted in an increase in lower and upper body strength, and improved aerobic fitness to a similar degree as aerobic training in coronary heart disease cohorts. Importantly, when progressive resistance training was added to aerobic training, effects on both fitness and strength were enhanced compared to aerobic training alone. Reporting of adverse events was poor, and clinical gaps were identified for women, older adults, high intensity progressive resistance training and long-term outcomes, warranting future trials to confirm safety and effectiveness.

The associations between polymorphisms in the CD36 gene, fat oxidation and cardiovascular disease risk factors in a young adult Australian population: A pilot study

Our pilot study in a young adult Australian cohort aimed to investigate potential associations between CD36 polymorphisms (rs1527479 and rs1984112), fat oxidation and cardiovascular disease risk. CD36 genotype was associated with fat oxidation during sub-maximal exercise, resting heart rate and blood pressure, indicating increased chronic disease risk in this otherwise healthy cohort.

Interactions Between Fatty Acid Transport Proteins, Genes that Encode for Them, and Exercise: A Systematic Review

Long‐chain fatty acid (LCFA) movement into skeletal muscle involves a highly mediated process in which lipid rafts are utilized in the cellular membrane, involving numerous putative plasma membrane‐associated LCFA transport proteins. The process of LCFA uptake and oxidation is of particular metabolic significance both at rest and during light to moderate exercise. A comprehensive systematic search of electronic databases was conducted to investigate whether exercise alters protein and/or gene expression of putative LCFA transport proteins. There were 31 studies meeting all eligibility criteria, of these 13 utilized an acute exercise protocol and 18 examined chronic exercise adaptations. Seventeen involved a study design incorporating an exercise stimulus, while the remaining 14 incorporated a combined exercise and diet stimulus. Divergent data relating to acute exercise, as well as prolonged exercise training (≥3 weeks), on protein content (PC) response was identified for proteins CD36, FABPpm and CAV1. Messenger ribonucleic acid (mRNA) data did not always correspond to functional PC, supporting previous suggestions of a disconnect due to potentially limiting factors post gene expression. The large array of study designs, cohorts, and primary dependent variables within the studies included in the present review elucidate the complexity of the interaction between exercise and LCFA transport proteins. Summary of the results in the present review validate the need for further targeted investigation within this topic, and provide an important information base for such research. J. Cell. Physiol. 231: 1671–1687, 2016.

Oxandrolone Augmentation of Resistance Training in Older Women: A Randomized Trial.

INTRODUCTION Sarcopenia is disproportionately present in older women with disability, and optimum treatment is not clear. We conducted a double-blind, randomized, placebo-controlled trial to determine whether oxandrolone administration in elderly women improves body composition or physical function beyond that which occurs in response to progressive resistance training (PRT). METHODS Twenty-nine sedentary women (age 74.9 ± 6.8 yr; 5.9 ± 2.8 medications per day) were randomized to receive high-intensity PRT (three times a week for 12 wk) combined with either oxandrolone (10 mg·d(-1)) or an identical placebo. Peak strength was assessed for leg press, chest press, triceps, knee extension, and knee flexion. Power was assessed for leg press and chest press. Physical function measures included static and dynamic balance, chair rise, stair climb, gait speed, and 6-min walk test. Body composition was assessed using dual energy x-ray absorptiometry. RESULTS Oxandrolone treatment augmented increases in lean tissue for the whole body (2.6 kg; 95% confidence interval (CI), 1.0-4.2 kg; P = 0.003), arms (0.3 kg; 95% CI, 0.1-0.5 kg; P = 0.001), legs (0.8 kg; 95% CI, 0.1-1.4 kg; P = 0.018), and trunk (1.4 kg; 95% CI, 0.4-2.3 kg; P = 0.004). Oxandrolone also augmented loss of fat tissue of the whole body (-1 kg; 95% CI, -1.6 to -0.4; P = 0.002), arms (-0.2 kg; 95% CI, -0.5 to -0.02 kg; P = 0.032), legs (-0.4 kg; 95% CI, -0.6 to -0.1; P = 0.009), and tended to reduce trunk fat (-0.4 kg; 95% CI, -0.9 to 0.04; P = 0.07). Improvements in muscle strength and power, chair stand, and dynamic balance were all significant over time (P < 0.05) but not different between groups (P > 0.05). CONCLUSIONS Oxandrolone improves body composition adaptations to PRT in older women over 12 wk without augmenting muscle function or functional performance beyond that of PRT alone.