Massimo Lanza

Both resistance training and aerobic training reduce hepatic fat content in type 2 diabetic subjects with nonalcoholic fatty liver disease (the RAED2 Randomized Trial).

Although lifestyle interventions are considered the first‐line therapy for nonalcoholic fatty liver disease (NAFLD), which is extremely common in people with type 2 diabetes, no intervention studies have compared the effects of aerobic (AER) or resistance (RES) training on hepatic fat content in type 2 diabetic subjects with NAFLD. In this randomized controlled trial, we compared the 4‐month effects of either AER or RES training on insulin sensitivity (by hyperinsulinemic euglycemic clamp), body composition (by dual‐energy X‐ray absorptiometry), as well as hepatic fat content and visceral (VAT), superficial (SSAT), and deep (DSAT) subcutaneous abdominal adipose tissue (all quantified by an in‐opposed‐phase magnetic resonance imaging technique) in 31 sedentary adults with type 2 diabetes and NAFLD. After training, hepatic fat content was markedly reduced (P < 0.001), to a similar extent, in both the AER and the RES training groups (mean relative reduction from baseline [95% confidence interval] −32.8% [−58.20 to −7.52] versus −25.9% [−50.92 to −0.94], respectively). Additionally, hepatic steatosis (defined as hepatic fat content >5.56%) disappeared in about one‐quarter of the patients in each intervention group (23.1% in the AER group and 23.5% in the RES group). Insulin sensitivity during euglycemic clamp was increased, whereas total body fat mass, VAT, SSAT, and hemoglobin A1c were reduced comparably in both intervention groups. Conclusion: This is the first randomized controlled study to demonstrate that resistance training and aerobic training are equally effective in reducing hepatic fat content among type 2 diabetic patients with NAFLD. (Hepatology 2013;58:1287–1295)

Metabolic Effects of Aerobic Training and Resistance Training in Type 2 Diabetic Subjects A randomized controlled trial (the RAED2 study)

OBJECTIVE To assess differences between the effects of aerobic and resistance training on HbA1c (primary outcome) and several metabolic risk factors in subjects with type 2 diabetes, and to identify predictors of exercise-induced metabolic improvement. RESEARCH DESIGN AND METHODS Type 2 diabetic patients (n = 40) were randomly assigned to aerobic training or resistance training. Before and after 4 months of intervention, metabolic phenotypes (including HbA1c, glucose clamp–measured insulin sensitivity, and oral glucose tolerance test–assessed β-cell function), body composition by dual-energy X-ray absorptiometry, visceral (VAT) and subcutaneous (SAT) adipose tissue by magnetic resonance imaging, cardiorespiratory fitness, and muscular strength were measured. RESULTS After training, increase in peak oxygen consumption (VO2peak) was greater in the aerobic group (time-by-group interaction P = 0.045), whereas increase in strength was greater in the resistance group (time-by-group interaction P < 0.0001). HbA1c was similarly reduced in both groups (−0.40% [95% CI −0.61 to −0.18] vs. −0.35% [−0.59 to −0.10], respectively). Total and truncal fat, VAT, and SAT were also similarly reduced in both groups, whereas insulin sensitivity and lean limb mass were similarly increased. β-Cell function showed no significant changes. In multivariate analyses, improvement in HbA1c after training was independently predicted by baseline HbA1c and by changes in VO2peak and truncal fat. CONCLUSIONS Resistance training, similarly to aerobic training, improves metabolic features and insulin sensitivity and reduces abdominal fat in type 2 diabetic patients. Changes after training in VO2peak and truncal fat may be primary determinants of exercise-induced metabolic improvement.

Positive effects of physical training in activity of daily living-dependent older adults.

The goal of this study was to determinate the effects of physical training in older adults with mobility limitations. Thirty frail women (84 ± 6 years) were randomly assigned to a training or control group for 12 weeks of upper body physical training (UBT) performed sitting on wheelchairs. Trained subjects showed a significant improvement in arms strength (+29%), and shoulder flexibility (+10 cm) but did not improve in arms circumference. The activities of daily living (ADLs) were improved (+77%), cognitive function as defined by the Mini-Mental State Examination (MMSE) was maintained in the trained group (+3%) and declined in the control group (−21%). These results demonstrate that UBT in dependent older women with mobility limitations can increase strength and improve ADLs.

Differences in the Acute Effects of Aerobic and Resistance Exercise in Subjects with Type 2 Diabetes: Results from the RAED2 Randomized Trial

Objective Both aerobic (AER) and resistance (RES) training, if maintained over a period of several months, reduce HbA1c levels in type 2 diabetes subjects. However, it is still unknown whether the short-term effects of these types of exercise on blood glucose are similar. Our objective was to assess whether there may be a difference in acute blood glucose changes after a single bout of AER or RES exercise. Study Design Twenty-five patients participating in the RAED2 Study, a RCT comparing AER and RES training in diabetic subjects, were submitted to continuous glucose monitoring during a 60-min exercise session and over the following 47 h. These measurements were performed after 10.9+0.4 weeks of training. Glucose concentration areas under the curve (AUC) during exercise, the subsequent night, and the 24-h period following exercise, as well as the corresponding periods of the non-exercise day, were assessed. Moreover, the low (LBGI) and high (HBGI) blood glucose indices, which summarize the duration and extent of hypoglycaemia or hyperglycaemia, respectively, were measured. Results AER and RES training similarly reduced HbA1c. Forty-eight hour glucose AUC was similar in both groups. However, a comparison of glucose AUC during the 60-min exercise period and the corresponding period of the non-exercise day showed that glucose levels were lower during exercise in the AER but not in the RES group (time-by-group interaction p = 0.04). Similar differences were observed in the nocturnal periods (time-by-group interaction p = 0.02). Accordingly, nocturnal LBGI was higher in the exercise day than in the non-exercise day in the AER (p = 0.012) but not in the RES group (p = 0.62). Conclusions Although AER and RES training have similar long-term metabolic effects in diabetic subjects, the acute effects of single bouts of these exercise types differ, with a potential increase in late-onset hypoglycaemia risk after AER exercise. Trial registration ClinicalTrials.gov NCT01182948

Assessment of Physical Activity in Anorexia Nervosa and Treatment Outcome

PURPOSE The aim of this study was to compare objective and subjective assessments of physical activity (PA) in patients with anorexia nervosa and its effect on treatment outcome. METHODS Both Actiheart (AH) and International Physical Activity Questionnaire (IPAQ) were used to assess PA in 52 female patients with anorexia nervosa during the first week of inpatient treatment. RESULTS No correspondence between PA estimated by IPAQ, which had a tendency to underestimate PA, and that measured using AH emerged. However, a significant association was found between the change in Eating Disorder Examination global score at the end of the treatment and light PA measured by AH (beta = -0.12, t = -2.44, P = 0.019), but not that estimated by IPAQ. CONCLUSIONS PA in patients with anorexia nervosa is underestimated by subjective assessment when compared with objective measurement. Only time spent in light PA, assessed objectively with AH, showed a negative association with improvement in eating disorder psychopathology.

Muscle fiber conduction velocity and fractal dimension of EMG during fatiguing contraction of young and elderly active men.

Over the past decade, linear and nonlinear surface electromyography (EMG) variables highlighting different components of fatigue have been developed. In this study, we tested fractal dimension (FD) and conduction velocity (CV) rate of changes as descriptors, respectively, of motor unit synchronization and peripheral manifestations of fatigue. Sixteen elderly (69  ±  4 years) and seventeen young (23  ±  2 years) physically active men (almost 3-5 h of physical activity per week) executed one knee extensor contraction at 70% of a maximal voluntary contraction for 30 s. Muscle fiber CV and FD were calculated from the multichannel surface EMG signal recorded from the vastus lateralis and medialis muscles. The main findings were that the two groups showed a similar rate of change of CV, whereas FD rate of change was higher in the young than in the elderly group. The trends were the same for both muscles. CV findings highlighted a non-different extent of peripheral manifestations of fatigue between groups. Nevertheless, FD rate of change was found to be steeper in the elderly than in the young, suggesting a greater increase in motor unit synchronization with ageing. These findings suggest that FD analysis could be used as a complementary variable providing further information on central mechanisms with respect to CV in fatiguing contractions.

Severe COPD Alters Muscle Fiber Conduction Velocity During Knee Extensors Fatiguing Contraction

Abstract The aim of this study was to assess the changes in muscle fiber conduction velocity (CV), as a sign of fatigue during knee extensor contraction in patients with chronic obstructive pulmonary disease (COPD) as compared with healthy controls. Eleven male patients (5 with severe and 6 with moderate COPD; age 67 ± 5 years) and 11 age-matched healthy male controls (age 65 ± 4 years) volunteered for the study. CV was obtained by multichannel surface electromyography (EMG) from the vastus lateralis (VL) and medialis (VM) of the quadriceps muscle during isometric, 30-second duration knee extension at 70% of maximal voluntary contraction. The decline in CV in both the VL and VM was steeper in the severe COPD patients than in healthy controls (for VL: severe COPD vs. controls −0.45 ± 0.07%/s; p < 0.001, and for VM: severe COPD vs. controls −0.54 ± 0.09%/s, p < 0.001). No difference in CV decline was found between the moderate COPD patients and the healthy controls. These findings suggest that severe COPD may impair muscle functions, leading to greater muscular fatigue, as expressed by CV changes. The results may be due to a greater involvement of anaerobic metabolism and a shift towards fatigable type II fibers in the muscle composition of the severe COPD patients.

Effects of Combined Aerobic-Strength Training vs Fitness Education Program in COPD Patients

We compared the effects of a new physical activity education program approach (EDU), based on a periodically supervised protocol of different exercise modalities vs traditionally supervised combined strength-endurance training (CT) on health-related factors in patients with stable chronic obstructive pulmonary disease (COPD). Twenty-eight COPD patients without comorbidities were randomly assigned to receive either EDU or CT. CT was continuously supervised to combine strength-endurance training; EDU was taught to progressively increase the rate of autonomous physical activity, through different training modalities such as Nordic walking, group classes and circuit training. Body composition, walking capacity, muscle strength, flexibility and balance, total daily energy expenditure and quality of life were evaluated at baseline, after 28 weeks training period (3d/week) and after a 14-week follow-up. No adverse events occurred during the interventions. After training, CT and EDU similarly improved walking capacity, body composition and quality of life. However, after 14 weeks of follow-up, such improvements were not maintained. Only in CT, muscle strength and flexibility improved after training but returned to baseline after follow-up. EDU, similar to CT, can effectively and safely improve health-related parameters in COPD patients. EDU could be an attractive alternative to traditional supervised training for improving quality of life in COPD patients.

Role of Exercise in Vascular Function and Inflammatory Profile in Age-Related Obesity

In western countries, aging is often accompanied by obesity and age-related obesity is characterized by vascular dysfunction and a low-grade inflammatory profile. Exercise is a nonpharmacological strategy able to decrease the development and incidence of risk factors for several health-threatening diseases. Nonetheless, its long-term effect on vascular function and inflammation in age-related obesity is still unclear. The aim of this study was to investigate the effect of regular, supervised exercise on inflammatory profile and vascular function in age-related obesity. We also hypothesized that vascular function and inflammatory profile would have been correlated in overweight and obese individuals. Thirty normal weight (NW; 70 ± 5 years, 23.9 ± 2.6 BMI) and forty overweight and obese elderly (OW&OB; 69 ± 5 years, 30.1 ± 2.3 BMI) regularly taking part in a structured, supervised exercise program were enrolled in the study and evaluated for vascular function (flow-mediated dilation; FMD) and inflammatory profile (plasma CRP, IL-1β, IL-1ra, IL-6, IL-8, IL-10, TNF-α, and MCP-1). Although no differences between groups were found concerning performance and the weekly amount of physical activity, the OW&OB group compared with the NW group demonstrated higher systolic and diastolic blood pressure (+10%, p = 0.001; +9%, p = 0.005, respectively); lower FMD% (−36%, p < 0.001) and FMD/shear rate (−40%, p = 0.001); and higher levels of CRP (+33%, p = 0.005), IL-6 (+36%, p = 0.048), MCP-1 (+17%, p = 0.004), and TNF-α (+16%, p = 0.031). No correlations between vascular function and inflammation were found in OW&OB or NW. Although exercising regularly, overweight and obese elderly exhibited poorer vascular function and higher proinflammatory markers compared with the leaner group. These results support the idea that exercise alone cannot counteract the negative effect of adiposity on vascular function and inflammatory profile in elderly individuals and these two processes are not necessarily related.

Does mild resistance training resemble a similar stimulus than aerobic training? - Authors' reply

We thank Pesta and Burtscher for their comments on our study. In this article, we have demonstrated, for the first time, that 4 months of resistance (RES) or aerobic (AER) training are equally effective in reducing hepatic fat content among sedentary type 2 diabetes subjects with nonalcoholic fatty liver disease (NAFLD). This study was a subproject of the RAED2 Study, a randomized, controlled trial aimed at comparing the metabolic effects of RES and AER training in diabetic patients. Pesta and Burtscher hypothesized that in untrained overweight/ obese subjects with little experience in exercise, RES training would be unable to induce the specific adaptations characteristic of this exercise modality, and that this, in turn, might explain why the results of AER and RES training were similar. We agree that, in untrained subjects, there may be some overlap between the effects of AER and RES training, and that the fullblown effects of these different exercise modalities can be only appreciated when sustained high-intensity training is performed, as occurs in athletes. Nonetheless, the latter would not be an appropriate model for assessing the effects of these training modalities on hepatic fat accumulation of sedentary subjects with type 2 diabetes, which was the aim of our study. Moreover, as reported previously, in our study, peak oxygen uptake improved after training in both groups, but to a greater extent in the AER group, whereas increased strength was found only in the RES group. In addition, lean mass of the limbs significantly increased in the RES group, but not in the AER group. These findings clearly indicate that the stimulus was quite different between the two protocols. These differences were guaranteed through a careful supervision of exercise sessions as well as a progressive increase of workload. In particular, as concerns the RES group, workload was gradually increased to 70%-80% 1-RM, with the weight being adjusted approximately every 2 weeks to match the progress of the subjects. With regard to baseline data, there were not statistically significant differences between groups. Overall, most type 2 diabetes patients are sedentary and have no experience with exercise programs. The clinical message that we were able to give is that exercise alone can provide benefit for NAFLD management in these patients, and that, after 4 months of training, RES exercise is as effective as AER exercise in reducing hepatic fat content in these subjects. Future research should address this important issue in the long term.