Impact of exercise intensity and duration on insulin sensitivity in women with T2D

Effect of resistance training on osteopenic rat bones in neonatal streptozotocin-induced diabetes: Analysis of GLUT4 content and biochemical, biomechanical, densitometric, and microstructural evaluation

AIMS

To investigate the effect of resistance training-RT on glycemia, expression of the glucose transporter-GLUT4, bone mineral density-BMD, and microstructural and biomechanical properties of osteopenic rat bones in neonatal streptozotocin-induced diabetes.

MAIN METHODS

Sixty-four 5-day-old male rats were divided into two groups: control and diabetic rats injected with vehicle or streptozotocin, respectively. After 55 days, densitometric analysis-DA of the tibia was performed. These groups were subdivided into four subgroups: non-osteopenic control-CN, osteopenic control-OC, non-osteopenic diabetic-DM, and osteopenic diabetic-OD. The OC and OD groups were suspended by their tails for 21 days to promote osteopenia in the hindlimb; subsequently, a second DA was performed. The rats were subdivided into eight subgroups: sedentary control-SC, sedentary osteopenic control-SOC, exercised control-EC, exercised osteopenic control-EOC, sedentary diabetic-SD, sedentary osteopenic diabetic-SOD, exercised diabetic-ED, and exercised osteopenic diabetic-EOD. For RT, the rats climbed a ladder with weights secured to their tails for 12 weeks. After RT, a third DA was performed, and blood samples, muscles, and tibias were assessed to measure glycemia, insulinemia, GLUT4 content, bone maximum strength, fracture energy, extrinsic stiffness, BMD, cancellous bone area, trabecular number, and trabecular width.

KEY FINDINGS

After RT, glycemia, GLUT4 content, BMD, and bone microstructural and biomechanical properties were improved in diabetic rats (osteopenic and non-osteopenic). However, RT had no effect on these parameters in the EC and SC groups.

SIGNIFICANCE

These results suggest that RT improves GLUT4 content, BMD, and microstructural and biomechanical properties of bone in osteopenic and non-osteopenic diabetic rats and is effective in controlling glycemia.

Abnormal Expression of microRNA-296-3p in Type 2 Diabetes Patients and its Role in Pancreatic β-Cells Function by Targeting Tensin Homolog Deleted on Chromosome Ten

Diabetes mellitus (DM), a familiar disease, is characterized by high blood glucose levels owing to insulin deficiency. Researches have suggested that the incidence rate of diabetes is increasing and it has become an important global epidemic. The type 2 diabetes mellitus (T2DM) is featured with pancreatic β-cell loss and lack of insulin release. Nevertheless, the therapeutic methods that was helpful to improve pancreatic β-cell damage still unclear. Previous report have revealed that tensin homolog deleted on chromosome ten (PTEN) was remarkably enhanced in serum of patients with T2DM, and the lack of PTEN may prevent function deficiency of pancreatic β-cells in DM. However, the underlying mechanisms are rarely illustrated. Our purpose in this report was to illustrated the roles and potential mechanism of microRNA-296-3p (miR-296-3p) in uric acid (UA)-induced pancreatic β-cell injury. The direct target of miR-296-3p was predicted and verified by dual-luciferase reporter system and TargetScan assay. Moreover, Min6 cells were induced by 5 mg/dl UA and the cell proliferation, apoptosis, and insulin release were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry and glucose-stimulated insulin secretion (GSIS), respectively. Quantitative reverse transcription PCR (qRT-PCR) and western blot assay were adopted to analyze the levels of miR-296-3p, PTEN and apoptosis-related proteins. TargetScan and Dual-luciferase reporter system confirmed that PTEN directly target miR-296-3p. MiR-296-3p was downregulated in UA-induced Min6 cells and the serum of type 2 diabetes patients, while PTEN was upregulated in UA-induced Min6 cells. Upregulation of miR-296-3p by mimic dramatically promoted miR-296-3p level and decreased PTEN level. Besides, PTEN was over-expressed after PTEN-plasmid transfection. UA treatment prominently decreased cell viability, promoted apoptotic cells, enhanced Bax levels, declined Bcl-2 level as well as decreased insulin release in Min6 cells. MiR-296-3p mimic significantly alleviated UA-induced pancreatic β-cells dysfunction, and PTEN-plasmid eliminated the protective effect of miR-296-3p on insulin release, cell viability, and apoptosis of pancreatic β-cells in UA-stimulated Min6 cells. In summary, our findings revealed that upregulation of miR-296-3p protected pancreatic β-cells functions against UA-induced dysfunction by targeting PTEN, which provides a novel agent for type 2 diabetes treatment.

Effects of a single bout of short-duration high-intensity and long-duration low-intensity exercise on insulin resistance and adiponectin/leptin ratio

OBJECTIVES

Moderate-intensity exercise improves insulin sensitivity, which may depend on the intensity, duration, and frequency of exercise. We examined the effects of a single bout of short-duration high-intensity exercise (HIE) and long-duration lowintensity exercise (LIE) on insulin sensitivity and the adiponectin/leptin ratio in individuals with different body mass indices (BMIs) who do not exercise regularly.

METHODS

We enrolled 42 healthy volunteers aged 20-64 years and divided them into two groups based on BMI: BMI <24 kg/m² and BMI ≥27 kg/m². They were randomly assigned to either the short-duration (20 min) HIE (70%-80% heart rate reserve, HRR) or long-duration (60 min) LIE training groups (30%-40% HRR). Glucose, insulin, adiponectin, and leptin levels were assessed before training and at 0, 30, 60, and 120 min after training.

RESULTS

We finally analyzed 27 normal weight and 9 obese individuals. No significant differences were observed in the baseline information of both BMI groups. Homeostatic model assessment for insulin resistance significantly improved for both exercise patterns in the normal weight group and for the HIE pattern in the obese group (P < 0.01), whereas the adiponectin/leptin ratio increased significantly only among normal weight participants with the LIE intervention.

CONCLUSION

Both exercise patterns in BMI <24 kg/m² and BMI ≥27 kg/m² benefit on insulin resistance. Therefore, people can choose the way they can fit to improve insulin resistance both short-duration high-intensity exercise and long-duration low-intensity exercise.

Lessons learned from community- and home-based physical activity programs: A narrative review of factors influencing women's participation in cardiac rehabilitation

BACKGROUND

Cardiovascular disease remains a leading cause of death in women. Despite the well-known benefits of cardiac rehabilitation, it remains underutilized, especially among women. Physical activity programs in the community, however, attract a large female population, suggesting that they overcome barriers to physical activity encountered by women. The characteristics of interventions that extend beyond the traditional cardiac rehabilitation model and promote physical activity merit examination.

OBJECTIVES

This narrative review aimed to: (a) summarize women's barriers to attend cardiac rehabilitation; (b) examine the characteristics of community- and home-based physical activity or lifestyle coaching interventions; and (c) discuss which barriers may be addressed by these alternative programs.

METHODS

Studies were included if they: (a) were published within the past 10 years; (b) included ≥70% women with a mean age ≥45 years; (c) implemented a community- or home-based physical activity intervention or a lifestyle education/behavioral coaching program; and (d) aimed to improve physical activity levels or physical function.

RESULTS

Most interventions reported high (≥70%) participation rates and significant increases in physical activity levels at follow-up; some improved physical function and/or cardiovascular disease risk factors. Community- and home-based interventions address women's cardiac rehabilitation barriers by: implementing appealing modes of physical activity (e.g. dancing, group-walking, technology-based balance exercises); adapting the program to meet participants' needs; offering flexible options regarding timing and setting (e.g. closer to home, the workplace or faith-based institutions); and promoting social interactions.

CONCLUSION

Cardiac rehabilitation can be enhanced by understanding the specific needs of women; novel elements such as program offerings, convenient settings and opportunities for socialization should be considered when designing cardiac rehabilitation programs.

PHYSICAL TRAINING ON GLYCEMIA AND OXIDATIVE STRESS IN TYPE 2 DIABETES: A SYSTEMATIC REVIEW

ABSTRACT Introduction: Diabetes mellitus is accompanied by increased formation of reactive oxygen species (ROS) and decreased antioxidant capacity, leading to oxidative damage to cellular components. There is evidence to suggest that regular physical training positively changes oxidative homeostasis in the cells and tissues by lowering basal levels of oxidative damage, increasing resistance to oxidative stress. Objective: To verify the possible effects of aerobic physical training and resistance on glycemia and oxidative metabolism, and to determine whether there is any difference in outcomes resulting from different types of training in sedentary people with Type 2 Diabetes Mellitus (T2DM). Methods: A systematic review of controlled and randomized trials based on PRISMA. The databases LILACS, IBECS, Pubmed/MEDLINE, Cochrane Library, SciELO, PEDro, ScienceDirect and BIREME were searched, combining the descriptors type 2 diabetes mellitus, resistance training, aerobic exercise and oxidative stress in Portuguese, English and Spanish. The methodological quality of the papers was assessed by the PEDro scale. The data were read, analyzed, extracted and summarized. Results: Of the 1386 papers retrieved, only five met the inclusion criteria. The five selected papers, consisting of controlled and randomized clinical trials, were summarized. Conclusion: There have been many published studies reporting on exercises and diabetes. However, there is limitation when it comes to comparing their results. The variability of research methods and measurement instruments used makes it difficult to draw conclusions as to which physical training modality is most effective in reducing glycemic levels and oxidative stress in sedentary individuals with T2DM, considering that in each study analyzed in this review, the response to these variables is different. In future research, it would be important to standardize exercise modality, intensity, training time and evaluation parameters. Level of evidence I; Systematic review of RCTs (Randomized controlled trials).

Exercise Intensities as Factors of Metabolic Outcomes in Type 2 Diabetes: A Systematic Review

Exercise is effective to prevent and treat type 2 diabetes, although currently underutilized. This review analyzes the metabolic response to exercise performance at various intensities in individuals with type 2 diabetes. These findings provide insight into the development of safe and efficacious exercise prescriptions and education. We conducted a systemic review of the literature to examine the association of various exercise protocols with metabolic outcomes in type 2 diabetes. Between 1984 and 2018, 29 studies were categorized per exercise mode and intensity levels according to the American College of Sports Medicine standards. The most consistent improvement was found in HbA1c following moderate- to high-intensity exercise—post-exercise fasting glucose improved to a lesser extent. Low-intensity exercise improved HOMA-IR (homeostasis model assessment for insulin resistance) levels. Glucose and HbA1c improved most following interval compared with continuous exercise, irrespective of intensity. A comparison of high-intensity exercise with moderate-intensity exercise demonstrated few differences in HbA1c, fasting glucose, fasting insulin, and HOMA-IR. Irrespective of exercise intensity, HbA1c improvements were observed, suggesting a delayed progression to diabetes-related complications. Initial low-intensity exercise, with increased quantities when feasible, will contribute to metabolic improvements. The variability in methodology and measurement contributed to inconsistent outcomes; additional research with larger samples sizes is warranted.

Associations of Physical Activity Intensities with Markers of Insulin Sensitivity

BACKGROUND

Objectively measured physical activity (PA) intensity has traditionally been categorized as light, moderate, and vigorous using laboratory calibrated cut points. The relative contribution of time spent across a spectrum of accelerometer-determined intensities on health outcomes is less clear.

PURPOSE

This study aimed to assess the relationship between objectively measured PA intensity on a continuous scale and markers of insulin sensitivity (IS).

METHODS

Participants at high risk of type 2 diabetes mellitus were recruited from primary care (Leicestershire, UK). PA was measured using an ActiGraph accelerometer. Fasting and postchallenge glucose and insulin levels were assessed using an oral glucose tolerance test. IS was calculated using the Matsuda-IS and the HOMA-IS indices. Log-linear regression modeling was used to assess the relationship between PA intensity, in increments of 500 counts per minute, with markers of IS. Models were controlled for known confounders.

RESULTS

Complete data were available for 569 participants. PA intensity was favorably associated with fasting and 2 h of insulin and IS, with the association increasing in magnitude with each increment of 500 counts per minute. Differences in HOMA-IS per 10 min of PA ranged from 12.4% (95% confidence interval = 3.7%-21.8%) to 26.8% (11.0%-44.7%) within the moderate-intensity PA category (from 2000-2499 to 3500-3999 counts per minute). For Matsuda-IS, these differences were 22.0% (10.3%-34.9%) and 34.7% (13.9%-59.3%), respectively. Significant associations for fasting insulin were no longer observed after controlling for body mass index, whereas differences associated with 2-h insulin and IS were attenuated but still significant.

CONCLUSION

PA of any intensity may positively influence glucose regulation and insulin sensitivity in individuals at high risk of type 2 diabetes mellitus in a dose-response manner. Further research is required to identify the intensity thresholds at which clinically relevant benefits occur in this population.

Effectiveness of a physical activity program on cardiovascular disease risk in adult primary health-care users: the "Pas-a-Pas" community intervention trial

BACKGROUND

Physical activity is a major, modifiable, risk factor for cardiovascular disease (CVD) that contributes to the prevention and management of CVD. The aim of this study was to assess the short- and medium-term effectiveness of 9 months of a supervised physical activity program, including sociocultural activities, on CVD risk in adults.

METHODS

Multicentered, randomized, controlled community intervention involving 364 patients in four primary care centers. The participants were randomly assigned to a Control Group (CG = 104) or Intervention Group (IG = 260); mean age 65.19 years; 76.8% women. The intervention consisted of 120 min/week walking (396 METs/min/week) and sociocultural gathering once a month. Clinical history, physical activity, dietary intake, CVD risk factors (smoking, systolic and diastolic blood pressure, weight, waist circumference, BMI, total cholesterol, LDL- and HDL-cholesterol, triglycerides, glycosylated hemoglobin and glucose) and global CVD risk were assessed at baseline and at the end of the intervention and multivariate models were applied to the data. Incidence of adverse cardiovascular events and continued adherence to the physical activity were assessed 2 years after intervention.

RESULTS

At the end of the intervention period, in the IG relative to the CG group, there was a significant increase in physical activity (774.81 METs/min/week), a significant change during the intervention period in systolic blood pressure (-6.63 mmHg), total cholesterol (-10.12 mg/dL) and LDL-cholesterol (-9.05 mg/dL) even after adjustment for potential confounders. At 2 years after the intervention, in the IG, compared with the CG, tthe incidence of adverse cardiovascular events was significantly lower (2.5% vs. 10.5%) and the adherence to regular physical activity was higher (72.8% vs 27.2%) in IG compared to CG.

CONCLUSIONS

This community-based physical activity program improved cardiovascular health in the short- as well as medium-term, and promoted regular physical activity in the medium-term in older Spanish adults.

TRIALS REGISTRATION

Clinicaltrials.gov ID NCT02767739 . Trial registered on May 5th, 2016. Retrospectively registered.

High-intensity aerobic interval training improves aerobic fitness and HbA1c among persons diagnosed with type 2 diabetes

PURPOSE

It remains to be established how high-intensity aerobic interval training (HAIT) affects risk factors associated with type 2 diabetes (TD2). This study investigated effects of HAIT on maximal oxygen uptake (VO_2max), glycated Hemoglobin type A1C (HbA1c), insulin resistance (IR), fat oxidation (FatOx), body weight (BW), percent body fat (%BF), lactate threshold (LT), blood pressure (BP), and blood lipid profile (BLP) among persons with T2D. Results were compared to the effects after a moderate-intensity training (MIT) program.

METHODS

Thirty-eight individuals with T2D completed 12 weeks of supervised training. HAIT consisted of 4 × 4 min of walking or running uphill at 85-95% of maximal heart rate, and MIT consisted of continuous walking at 70-75% of maximal heart rate.

RESULTS

A 21% increase in VO_2max (from 25.6 to 30.9 ml kg^-1 min^-1, p < 0.001), and a reduction in HbA1c by -0.58% points (from 7.78 to 7.20%, p < 0.001) was found in HAIT. BW and body mass index (BMI) was reduced by 1.9% (p < 0.01). There was a tendency towards an improved FatOx at 60% VO_2max (14%, p = 0.065). These improvements were significant different from MIT. Both HAIT and MIT increased velocity at LT, and reduced %BF, waist circumference, hip circumference, and BP, with no significant differences between the two groups. Correlations were found between change in VO_2max and change in HbA1c when the two intervention groups were combined (R = -0.52, p < 0.01).

CONCLUSION

HAIT is an effective exercise strategy to improve aerobic fitness and reduce risk factors associated with T2D.

[Physical activity and Framingham risk score in older adults: the Bambuí Health and Aging Study]

This study explored the association between energy expenditure during physical activity and the Framingham risk score in the elderly. This was a cross-sectional study with a sample of 1,473 older adults. The dependent variable was level of physical activity, estimated by the metabolic equivalents in tertiles. The exploratory variables were the components of the Framingham risk score and the Framingham risk score itself. The force of associations was estimated by odds ratios and confidence intervals using ordinal logistic regression. Higher physical activity was associated with lower Framingham risk score, younger age, lower proportion of diabetes, and higher mean HDL levels. Higher energy expenditure was also associated with lower odds of smoking in men. The findings suggest that the adoption of a physically active lifestyle can reduce coronary risk, and that the promotion of physical activity is a universal strategy to fight chronic noncommunicable diseases.

Vigorous exercise is associated with superior metabolic profiles in polycystic ovary syndrome independent of total exercise expenditure

OBJECTIVE

To characterize metabolic features of women with polycystic ovary syndrome (PCOS) by exercise behavior and determine relative health benefits of different exercise intensities.

DESIGN

Cross-sectional study.

SETTING

Tertiary academic institution.

PATIENT(S)

Three hundred and twenty-six women aged 14-52 years-old with PCOS by Rotterdam criteria examined between 2006 and 2013.

INTERVENTION(S)

International Physical Activity Questionnaire (IPAQ) administered to classify patients into three groups based on Department of Health and Human Services (DHHS) Guidelines of vigorous, moderate, and inactive, along with physical examination and serum testing.

MAIN OUTCOME MEASURE(S)

Blood pressure, body mass index (BMI), waist circumference, fasting lipids, fasting glucose and insulin, 2-hour 75-gram oral glucose tolerance, homeostatic model assessment of insulin resistance (HOMA-IR).

RESULT(S)

The DHHS guidelines for adequate physical activity were met by 182 (56%) women. Compared with moderate exercisers and inactive women, the vigorous exercisers had lower BMI and lower HOMA-IR; higher levels of high-density lipoprotein cholesterol and sex hormone-binding globulin; and a reduced prevalence of the metabolic syndrome. In a multivariate logistic regression analysis controlling for age, BMI, and total energy expenditure, every hour of vigorous exercise reduced a patient's odds of metabolic syndrome by 22% (odds ratio 0.78; 95% confidence interval, 0.62, 0.99).

CONCLUSION(S)

Women with PCOS who met DHHS guidelines for exercise demonstrated superior metabolic health parameters. Vigorous but not moderate activity is associated with reduced odds of the metabolic syndrome, independent of age, BMI, and total energy expenditure. PCOS patients should be encouraged to meet activity guidelines via vigorous physical activity.

An investigation and comparison of the effectiveness of different exercise programmes in improving glucose metabolism and pancreatic β cell function of type 2 diabetes patients

BACKGROUND

Moderately intensive aerobic exercise can improve glucose metabolism and pancreatic β cell function in diabetic patients. To date, there is no evidence to support the long-term effectiveness of home-based exercise interventions on these outcomes.

OBJECTIVE

This study investigated the effectiveness of two moderately intense exercise programmes on glucose metabolism and pancreatic β cell function in type 2 diabetes mellitus (T2DM) patients.

METHODS

A randomised controlled trial of 120 T2DM patients (with a mean age of 55.54 ± 9.09 years) was conducted. Patients were assigned by block randomisation to either an aerobic exercise group (AEG), an accumulated million steps group (AMSG), or a control group (CG); each consisting of 40 patients. Glucose metabolism and pancreatic β cell function of patients were measured at three time intervals for 1 year.

RESULTS

There was no difference in baseline scores, and respective compliance rates for the AEG and AMSG were 94.4% and 99.2%. After generalised estimating equation analysis, the AMSG results for glycated haemoglobin (HbA1c) were significantly lower than those of the CG. The insulinogenic index-acute insulin response (BIGTT-AIR ) of both exercise groups was significantly higher than that of the CG. The AMSG group improved their overall HbA1c and BIGTT-AIR results compared with the AEG group after 3 months exercise programme (T1 ) and 12 months of implementation (T2 ).

CONCLUSION

This study demonstrates that regardless of the type of exercise intervention, it is potentially beneficially effective for glucose metabolism and pancreatic β cell function in T2DM patients. The AMSG had better glucose metabolism and pancreatic β cell function compared with those in the AEG. Nurses can easily integrate exercise interventions into T2DM patient care plans.

Objectively measured sedentary time and associations with insulin sensitivity: Importance of reallocating sedentary time to physical activity

OBJECTIVE

The aim of this study is to quantify associations between objectively measured sedentary time and markers of insulin sensitivity by considering allocation into light-intensity physical activity or moderate- to vigorous-intensity physical activity (MVPA).

METHODS

Participants with an increased risk of impaired glucose regulation (IGR) were recruited (Leicestershire, United Kingdom, 2010-2011). Sedentary, light-intensity physical activity and MVPA time were measured using accelerometers. Fasting and 2-hour post-challenge insulin and glucose were assessed; insulin sensitivity was calculated by HOMA-IS and Matsuda-ISI. Isotemporal substitution regression models were used. Data were analysed in 2014.

RESULTS

508 participants were included (average age=65years, female=34%). Reallocating 30min of sedentary time into light-intensity physical activity was associated a 5% (95% CI 1, 9%; p=0.024) difference in Matsuda-ISI after adjustment for measured confounding variables. Reallocation into MVPA was associated with a 15% (7, 25%; p<0.001) difference in HOMA-IS and 18% (8, 28%; p<0.001) difference in Matsuda-ISI. Results for light-intensity physical activity were modified by IGR status with stronger associations seen in those with IGR.

CONCLUSIONS

Reallocating sedentary time into light-intensity physical activity or MVPA was associated with differences in insulin sensitivity, with stronger and more consistent associations seen for MVPA.

Effects of exercise training using resistance bands on glycaemic control and strength in type 2 diabetes mellitus: a meta-analysis of randomised controlled trials

Resistance exercise using free weights or weight machines improves glycaemic control and strength in people with type 2 diabetes. Resistance band training is potentially less expensive and more accessible, but the effects of resistance band training on glycaemic control and strength in this population are not well understood. This paper aims to systematically review and meta-analyse the effect of resistance band training on haemoglobin A1c (HbA1c) and strength in adults with type 2 diabetes. Database searches were performed in August 2013 (MEDLINE, SPORTDiscus, EMBASE, and CINAHL). Reference lists of eligible articles were hand-searched for additional studies. Randomised trials evaluating the effects of resistance band training in adults with type 2 diabetes on HbA1c or objectively measured strength were selected. Baseline and post-intervention HbA1c and strength were extracted for the intervention and control groups. Details of the exercise interventions and methodological quality were collected. Seven trials met inclusion criteria. Post-intervention-weighted mean HbA1c was nonsignificantly lower in exercise groups compared to control groups [weighted mean difference (WMD) = -0.18 percentage points (-1.91 mmol/mol); P = 0.27]. Post-intervention strength was significantly higher in the exercise groups compared to the control groups in the lower extremities (WMD = 21.90 kg; P < 0.0001), but not in the upper extremities (WMD = 2.27 kg; P = 0.13) or handgrip (WMD = 1.98 kg; P = 0.46). All trials were small and had methodological limitations. Resistance band training did not significantly affect HbA1c, upper extremity, or handgrip strength but significantly increased the strength of the lower extremities in people with type 2 diabetes.

Gender differences in the relationship between anxiety symptoms and physical inactivity in a community-based sample of adults with type 2 diabetes

OBJECTIVE

To examine the association between physical inactivity and anxiety symptoms in a community-based sample of men and women with type 2 diabetes mellitus.

METHODS

Eligibility criteria included residents of Quebec, Canada aged between 40 and 75 years, having a diagnosis of type 2 diabetes (≤10 years), being insulin-naive and having participated in a previous telephone-based survey of diabetes treatments. Of the 2028 eligible respondents, 1953 (96.3%) provided information on anxiety symptoms and were included in this analysis. Participants were interviewed and provided information on diabetes-related clinical and sociodemographic factors.

RESULTS

A total of 27.3% of participants reported being physically inactive. The prevalence of mild to severe anxiety symptoms was 22.9%. Persons with mild anxiety symptoms and moderate to severe anxiety symptoms were 1.4 times and 1.7 times more likely to report being inactive than persons without anxiety symptoms, respectively. Subgroup analyses according to gender revealed that women who had mild anxiety symptoms were 1.5 times more likely to report being inactive compared with women who did not have anxiety symptoms, whereas men who had moderate to severe anxiety symptoms were 2.5 times more likely to be inactive than men who did not have anxiety symptoms.

CONCLUSIONS

Anxiety symptoms in the mild and moderate to severe range are a relevant clinical comorbidity in persons with type 2 diabetes, and men may represent a particularly vulnerable subgroup. Future research is recommended to further assess the relationship between anxiety symptoms and diabetes-related health behaviours.

Injury Rate and Patterns Among CrossFit Athletes

Background:

CrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates.

Purpose:

To establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and demographic categories, gym characteristics, and athletic abilities among CrossFit participants.

Study Design:

Descriptive epidemiology study.

Methods:

A survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia, Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further, and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using Fisher exact tests and chi-square tests.

Results:

A total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P = .03). Across all exercises, injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last, the injury rate was significantly decreased with trainer involvement (P = .028).

Conclusion:

The injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.

Effect of intensity of aerobic training on insulin sensitivity/resistance in recreationally active adults

Previous research demonstrates that moderate-intensity aerobic exercise improves insulin effectiveness. Whether higher exercise intensities improve insulin action more so is unclear. The purpose of this study was to evaluate the effect of various levels of aerobic intensity on insulin action in young adult men and women. Forty-five healthy subjects (22.2 ± 3.9 years; 169 ± 9 cm; 74.5 ± 17.8 kg) were matched for age, gender, and VO2max and randomly assigned to moderate-intensity (50% heart rate reserve [HRR]), vigorous-intensity (75% HRR), maximal-intensity intervals (95/50% HRR) or a non-exercising control group. Subjects completed a 6-week training protocol on a stationary bicycle ergometer. Weekly duration and frequency of training varied to ensure equivalent energy expenditure across groups. The homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) were used to assess insulin effectiveness. Significant increases occurred after training in VO2max in the vigorous-intensity(15.4%) and maximal-intensity(14.2%) groups (p < 0.01) but not the moderate-intensity or control group. There were no significant changes in insulin effectiveness in any exercise group. Training intensity did not significantly affect insulin effectiveness in a young adult population as assessed by HOMA or QUICKI; it did, however, significantly affect VO2max.

Evidence for the benefit of exercise therapy in patients with type 2 diabetes

Exercise interventions are recommended in most guidelines for the treatment of type 2 diabetes. Although most guidelines suggest a combination of both aerobic and resistance training, the exact benefits of these interventions remain unclear. Although either modality alone or in combination seems to have an identical impact on glycated hemoglobin levels, resistance training and aerobic training have independent effects on other parameters of cardio-metabolic risk. This review examines the current evidence for aerobic and resistance training on glycemic control, lipid profile, body composition, vascular health, and mental health in patients with type 2 diabetes. The uncertainties surrounding exercise modality, volume and intensity are also addressed.

Cancer cachexia prevention via physical exercise: molecular mechanisms

Cancer cachexia is a debilitating consequence of disease progression, characterised by the significant weight loss through the catabolism of both skeletal muscle and adipose tissue, leading to a reduced mobility and muscle function, fatigue, impaired quality of life and ultimately death occurring with 25-30 % total body weight loss. Degradation of proteins and decreased protein synthesis contributes to catabolism of skeletal muscle, while the loss of adipose tissue results mainly from enhanced lipolysis. These mechanisms appear to be at least, in part, mediated by systemic inflammation. Exercise, by virtue of its anti-inflammatory effect, is shown to be effective at counteracting the muscle catabolism by increasing protein synthesis and reducing protein degradation, thus successfully improving muscle strength, physical function and quality of life in patients with non-cancer-related cachexia. Therefore, by implementing appropriate exercise interventions upon diagnosis and at various stages of treatment, it may be possible to reverse protein degradation, while increasing protein synthesis and lean body mass, thus counteracting the wasting seen in cachexia.

Combined exercise for people with type 2 diabetes mellitus: a systematic review

Type 2 diabetes mellitus has emerged as a major non-communicable chronic diseases in many countries. The importance of exercise in the prevention and management of this disease is evident. This paper briefly reviews the effects of combining aerobic and resistance exercises on glycemic control, and details the training and characteristics of various interventions in adults with type 2 diabetes mellitus. Literature searches were performed using electronic databases between the 1st of January 1950 and the 15th of September 2011. Of the 403 articles retrieved, 28 studies met our inclusion criteria. Combined exercise protocols seem to improve glycemic control to a greater extent than isolated forms of exercise. Nevertheless, length, duration, intensity, mode, number of exercises, sets and repetitions varied markedly among studies. Supervised training sessions, recommended structured exercises, and splitting aerobic and resistance training in separate sessions may be relevant for best results. Future studies should analyze the effects of different aerobic and resistance training modes, different training and progression methods, and whether one type of exercise is optimal, as these issues are likely to convey greater knowledge on type 2 diabetes mellitus management through combined exercise.

Exercise and type 2 diabetes: new prescription for an old problem

During the past 50 years, the prevalence of a cluster of chronic, inactivity-related diseases including obesity, insulin resistance and type 2 diabetes mellitus (T2DM), collectively referred to as 'metabolic syndrome' (MetS) has reached global epidemic proportions. Appropriate exercise training is a clinically proven, cost-effective, primary intervention that delays and in many cases prevents the health burdens associated with MetS. Indeed, there is no single intervention with greater efficacy than physical exercise to reduce the risk of virtually all chronic diseases simultaneously. However compliance to National guidelines for physical activity remains low, with "a lack of time" the most frequently cited barrier to exercise participation by adults, irrespective of age, sex and ethnic background. Part of the growing apathy to modify lifestyle habits is that current public health recommendations may be unrealistic and unattainable for the majority of the populace. Hence, there is an urgent need for innovations in exercise prescription that can be incorporated into daily living and induce clinically beneficial health outcomes. Here we focus attention on a novel form of exercise prescription, high-intensity interval training (HIT), and provide evidence that HIT is a time-efficient and well-tolerated therapeutic intervention to improve cardio-metabolic health in a number of pre-clinical and clinical populations.

Efeito do treinamento combinado e aeróbio no controle glicêmico no diabetes tipo 2

INTRODUÇÃO: O diabetes tipo 2 é um grupo heterogêneo de doença metabólica causada por uma disfunção na secreção da insulina e/ou ação desta. OBJETIVOS: Comparar o efeito de duas modalidades de treinamento, o combinado (aeróbio e resistido) e o aeróbio, no controle glicêmico no diabetes tipo 2. MATERIAIS E MÉTODOS: A pesquisa caracteriza-se por ser um estudo quase-experimental. Após aprovação do CEP, com registro 09.071.4.08. III, deu-se início ao programa de treinamento combinado e aeróbio. Foram selecionados 24 participantes, de ambos os gêneros, sedentários, com média de idade de 60,41 ± 7,87. Os participantes foram divididos aleatoriamente em dois grupos: treinamento combinado (n = 12) e treinamento aeróbio (n = 12); ambos foram avaliados no início e final do estudo. A concentração sérica de glicose foi determinada pelo sistema Vitros e a hemoglobina glicosilada foi determinada pelo método Cromatografia Líquida de Alta Performance. O treinamento foi realizado três vezes por semana, com duração total de 20 semanas. Os dados são expressos em média e desvio-padrão. Foi aplicado o teste t pareado (p < 0,05) para comparar a média basal e após 20 semanas de treinamento. RESULTADOS: A média da glicose em jejum do treinamento combinado reduziu significativamente, de 167,41 ± 38,13 para 119,83 ± 20,91, sendo que o mesmo ocorreu com o treinamento aeróbio de 189,83 ± 63,57 para 139,91 ± 34,04. Os valores da hemoglobina glicosilada no treinamento combinado e treinamento aeróbio reduziram significativamente, de 8,61 ± 1,17 para 7,25 ± 1,24 e de 9,52 ± 2,46 para 8,37 ± 1,50, respectivamente. CONCLUSÃO: O treinamento combinado foi mais eficaz em relação à hemoglobina glicosilada e o treinamento aeróbio, na glicose plasmática.