Rugby-specific small-sided games training is an effective alternative to stationary cycling at reducing clinical risk factors associated with the development of type 2 diabetes: a randomized, controlled trial

Effects of recreational team sports on the metabolic health, body composition and physical fitness parameters of overweight and obese populations: A systematic review

This systematic review aims to provide a summary of the results from individual studies that specifically focused on overweight or obese populations, regardless of age or sex. The goal is to determine the effects of structured recreational team sports interventions (TSG) on metabolic health, body composition and physical fitness parameters when compared to passive or active control groups. This study adhered to the PRISMA guidelines for reporting a systematic review. A thorough examination of relevant literature was conducted on November 06, 2023, using three prominent databases: PubMed, Scopus, and the Web of Science. Inclusion criteria considered overweight (e.g., BMI 25.0-29.9 kg/m2) and obese (e.g., BMI > 30 kg/m2) populations exposed to training interventions using recreational team sports, while the comparator group consisted of the same populations not exposed to exercise (passive controls) or exposed to alternative training methods. The primary outcomes of interest were metabolic health parameters (glucose, waist circumference, blood pressure, cholesterol, triglycerides), body composition (e.g., fat mass, lean mass), as well as physical fitness parameters (e.g., aerobic fitness, muscular fitness). Only studies with two- or multi-arm designs, whether randomized or not, were eligible for inclusion. The PEDro scale was used to assess the methodological bias of the included studies. Out of the initial 275 titles retrieved, we deemed ten eligible for our study. In terms of body composition, TSG demonstrated a significant decrease in body mass index across three studies (-2.3 to -5.1%) and a significant reduction in waist circumference in four studies (-4.6% to -8.4%). Regarding blood pressure, TSG exhibited a significant decrease in systolic blood pressure in two studies (-3.9% to -8.3%), while diastolic blood pressure showed a significant decrease in only one study (-7.3%). Cholesterol levels saw a significant decrease in TSG in three studies (-7.0% to -9.7%), and triglyceride levels showed a significant reduction in four studies (-16.4% to -20.1%). In terms of aerobic fitness, TSG demonstrated within-group improvements in the field-based tests in three studies (8.1% to 79.0%), and within-group improvements in maximal oxygen uptake in four studies (6.5% to 31.0%), with significant favoring of TSG in most studies. Overall, TSG demonstrated significant benefits for overweight and obese populations compared to the control group, particularly in terms of improvements in body mass index, systolic blood pressures, cholesterol and triglyceride levels, and aerobic fitness. Future research ought to concentrate on tailoring responses to varying training volumes on an individualized basis.

A 3-Month Modified Basketball Exercise Program as a Health-Enhancing Sport Activity for Middle-Aged Individuals

Recreational team sports have received great acceptance lately, in different populations, indicating encouraging results in health-related quality of life. This study examined the efficacy of a 3-month basketball exercise program on selected indices of health (body mass-BM, body fat-BF, blood pressure-BP), functional capacity (flexibility of lower and upper limbs, balance), and physical fitness (maximum strength of lower limbs, trunk and handgrip, aerobic capacity) in middle-aged individuals. Forty middle-aged individuals (males and females; 40-55 years old) were randomly divided into (a) exercise (EG; n = 20) and (b) control groups (CG; n = 20). The EG followed a 3-month modified basketball exercise program (2 times/week; 24 training units), including different basketball drills with and without the ball (dribbling, passing, pivot, stops, etc.), to improve participants' health and physical fitness. Repeated measures ANOVA showed that the EG significantly increased their flexibility (17.23-74.88%; p < 0.001), static balance (44.76-54.69%; p < 0.001), and strength of lower limbs and trunk (11.67-13.13%; p < 0.001), while reducing BP (7.31-12%; p < 0.001), heart rate and RPE (5.30-34.37%; p < 0.001), and time during time-up-and-go test (-10.91%; p < 0.001). Handgrip strength, BM, and BF did not change following the program in the EG (p > 0.05). In the CG, the above variables remained stable. In conclusion, this program may be used to eliminate the detrimental effects of aging on health, functional capacity, and physical fitness parameters.

Health Benefits of Different Sports: a Systematic Review and Meta-Analysis of Longitudinal and Intervention Studies Including 2.6 Million Adult Participants

BACKGROUND

Several reviews have examined the health benefits of participation in specific sports, such as baseball, cricket, cross-country skiing, cycling, downhill skiing, football, golf, judo, rugby, running and swimming. However, new primary studies on the topic have recently been published, and the respective meta-analytic evidence needs to be updated.

OBJECTIVES

To systematically review, summarise and appraise evidence on physical health benefits of participation in different recreational sports.

METHODS

Searches for journal articles were conducted in PubMed/MEDLINE, Scopus, SpoLit, SPORTDiscus, Sports Medicine & Education Index and Web of Science. We included longitudinal and intervention studies investigating physical health outcomes associated with participation in a given sport among generally healthy adults without disability.

RESULTS

A total of 136 papers from 76 studies conducted among 2.6 million participants were included in the review. Our meta-analyses of available evidence found that: (1) cycling reduces the risk of coronary heart disease by 16% (pooled hazard ratio [HR] = 0.84; 95% confidence interval [CI]: 0.80, 0.89), all-cause mortality by 21% (HR = 0.79; 95% CI: 0.73, 0.84), cancer mortality by 10% (HR = 0.90; 95% CI: 0.85, 0.96) and cardiovascular mortality by 20% (HR = 0.80; 95% CI: 0.74, 0.86); (2) football has favourable effects on body composition, blood lipids, fasting blood glucose, blood pressure, cardiovascular function at rest, cardiorespiratory fitness and bone strength (p < 0.050); (3) handball has favourable effects on body composition and cardiorespiratory fitness (p < 0.050); (4) running reduces the risk of all-cause mortality by 23% (HR = 0.77; 95% CI: 0.70, 0.85), cancer mortality by 20% (HR = 0.80; 95% CI: 0.72, 0.89) and cardiovascular mortality by 27% (HR = 0.73; 95% CI: 0.57, 0.94) and improves body composition, cardiovascular function at rest and cardiorespiratory fitness (p < 0.010); and (5) swimming reduces the risk of all-cause mortality by 24% (HR = 0.76; 95% CI: 0.63, 0.92) and improves body composition and blood lipids (p < 0.010).

CONCLUSIONS

A range of physical health benefits are associated with participation in recreational cycling, football, handball, running and swimming. More studies are needed to enable meta-analyses of health benefits of participation in other sports. PROSPERO registration number CRD42021234839.

Effects of a 16-week recreational small-sided games soccer intervention on body composition and physical fitness in sedentary young adults: A randomized controlled study

Recreational small-sided games (SSGs) have demonstrated positive effects on body composition and physical fitness, while minimizing adverse outcomes. In this randomized controlled study, we aimed to investigate the impact of incorporating an additional 16-week intervention program involving recreational soccer SSGs on parameters related to body composition and physical fitness in sedentary young adult males and females. Sixty sedentary participants, with a mean age of 20.2 years, were randomly assigned to either the small-sided games group (SSG; n = 30) or the active control group, which participated in regular physical education classes (CG; n = 30). The SSG group engaged in the same activities as the control group but additionally participated in a recreational SSG football program. This program involved continuous and intermittent moderate-to high-intensity exercises conducted on 20 m × 30 m and 30 m × 50 m football fields. In contrast, the CG group received 1 h of physical education once a week. The interventions were administered for a duration of sixteen weeks. Baseline, 8-week, and post-intervention assessments were conducted to measure body mass (BM), body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), skinfold thickness (SFT), standing broad jump (SBJ), vertical jump (VJ), handgrip strength (HG) for both left and right hands, shuttle run distance (SRD), and shuttle run estimated VO2max. Results indicated that both male and female participants in the SSG group exhibited significant improvements in BM, BMI, SFT, WC, HC, and WHR following the intervention (p < 0.05), whereas the control group demonstrated no significant changes over the study period (p > 0.05). Additionally, SSG participants (regardless of sex) displayed significant enhancements in SBJ, VJ, HG, SRD, and VO2max (p < 0.05), while the control group did not exhibit any significant alterations (p > 0.05). The findings from this experimental study suggested that a 16-week recreational soccer SSG intervention effectively enhanced body composition and physical fitness among overweight sedentary young adults, offering a pleasurable alternative to conventional training approaches.

The effects of exercise training on postprandial glycemia and insulinemia in adults with overweight or obesity and with cardiometabolic disorders: a systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis to investigate the effects of exercise training on postprandial glycemia (PPG) and insulinemia (PPI) in adults with overweight or obesity and with cardiometabolic disorders.

METHODS

PubMed, Web of Science, and Scopus databases were searched until May 2022 using the key words "exercise," "postprandial," and "randomized control trial" to identify original studies investigating the effects of exercise training on PPG and/or PPI in adults with a body mass indexes (BMI) ≥ 25 kg.m². Standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated using random effects models to calculate effect sizes for outcomes and to generate forest plots. Sub-group analyses and meta-regressions were performed for potential categorical and continuous moderators.

RESULTS

Twenty-nine studies involving 41 intervention arms and 1,401 participants were included in the systematic review and meta-analysis. Overall, exercise training significantly decreased PPG [-0.36 (95% CI -0.50 to -0.22), p=0.001] and PPI [-0.37 (95% CI -0.52 to -0.21), p=0.001]. Subgroup analyses showed that PPG decreased following both aerobic and resistance training; whereas PPI was reduced following aerobic training, independent of age, BMI, and baseline glucose levels. Meta-regression analyses showed that frequency of exercise sessions, intervention durations, and duration of exercise time, did not moderate the effects of exercise training on PPI or PPG (p>0.05).

CONCLUSION

In adults with overweight or obesity and with cardiometabolic disorders, exercise training is effective for reducing PPG and PPI, across ages and BMIs, irrespective of baseline glucose levels and exercise training characteristics.

The sirtuin family in health and disease

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

Effects of recreational sports and combined training on blood pressure and glycated hemoglobin in middle-aged and older adults: A systematic review with meta-analysis

BACKGROUND

Combined resistance and aerobic training (CT) is the most suitable form of exercise training to simultaneously improve strength and cardiometabolic profile in middle-aged and older adults. Recreational sports (RS) emerge as an alternative to CT to improve these outcomes. We performed a meta-analysis on the effects of RS and CT on systolic blood pressure (SBP), diastolic blood pressure (DBP) and glycated hemoglobin (HbA1c) in middle-aged and older adults and to compare these exercise interventions to a non-exercising control group (CON).

METHODS

Search was conducted using the databases at PubMed, COCHRANE and SciELO between July and August 2020. Studies that included men and women aged ≥45 years, healthy or with values for SBP ≥130 mmHg or DBP ≥80 mmHg or with type 2 diabetes and performed RS or CT versus CON.

RESULTS

From 6017 records, 27 studies were included (9 RS and 18 CT). The analysis included 1411 participants with 55 ± 8 years. RS and CT were associated with reductions in SBP (RS: -7.2 mmHg, P = 0.03; CT: -3.6 mmHg, P < 0.001) and DBP (RS: -3.6 mmHg, P = 0.02; CT: -3.1 mmHg, P < 0.001) versus CON. Only CT was associated with a reduction in HbA1c versus CON (-0.47%; P < 0.001).

CONCLUSIONS

RS and CT are effective exercise interventions to improve BP in middle-aged and older adults. CT seems to be an excellent strategy to reduce HbA1c, and future studies are necessary to confirm the effectiveness of RS to improve HbA1c.

Randomised controlled trial comparing two group-based exercise programmes (team sport vs circuit training) on men's health: study protocol

Introduction

Physical activity promotes physical, psychological and social health. Despite this, almost half of middle-aged (35–54 years) Australian men are insufficiently active. Exercise adherence is increased with social interaction in a group setting. Team sport can leverage the power of groups and has shown to be more intrinsically motivating than discrete exercise modes. Evaluation of the effect of team sport compared with traditional group exercise on health, particularly psychological and social health, and physical activity levels of middle-aged men is limited. This study aims to compare the effects of team sport participation and group circuit training on physical activity levels and health in insufficiently active middle-aged men.

Methods and analysis

In this parallel randomised controlled trial, n=128 men aged 35–54 years will complete a 12-week team sport or group circuit exercise programme. Participants must self-report to not be meeting Australian physical activity guidelines or participating in team sport before recruitment. Health-related quality of life, exercise motivation, psychological needs satisfaction, sleep and physical activity levels (accelerometry), blood lipids, glucose and metabolic syndrome risk score will be assessed at baseline, end of the programme and 12 weeks follow-up. Linear mixed effect models will be used.

Ethics and dissemination

The study has received ethical approval from the University of South Australia’s Human Research Ethics Committee (Ethics Protocol 203274). Study results will be disseminated via publication in disciplinary-specific journals, conference presentations, and as part of a Doctoral thesis.

Trial registration number

ANCTRN12621000483853.

A systematic review of small sided games within rugby: Acute and chronic effects of constraints manipulation

Small-sided games is a commonly used training method to develop technical, tactical and physical qualities concurrently. However, a review of small-sided games in rugby football codes (e.g. rugby union, rugby league) is not available. This systematic review aims to investigate the acute responses and chronic adaptations of small-sided games within rugby football codes considering the constraints applied. Four electronical databases were systematically searched until August 2020. Acute and chronic studies investigating rugby football codes small-sided games, with healthy amateur and professional athletes were included. Twenty studies were eventually included: 4 acute and 1 chronic in rugby union, 13 acute and 2 chronic in rugby league. Acute studies investigated task and individual constraints. Chronic studies showed that small-sided games would be an effective training method to improve physical performance. Current research in rugby football codes is heavily biased towards investigating how manipulating constraints can affect the physical characteristics of small-sided games, with limited literature investigating the effect on technical skills, and no studies investigating tactical behaviour. Future research is needed to evidence the effects of constraint manipulation on technical and tactical behaviour of rugby football players in small-sided games, in addition to physical characteristics.

Cardiovascular fitness and health effects of various types of team sports for adult and elderly inactive individuals - a brief narrative review

Recreational team sports offer an alternative form of exercise to inactive individuals across the lifespan and sexes. Soccer is the most investigated recreational team sport reporting a wide range of health benefits, including cardiovascular (CV) health. The quest for novel paradigms to promote exercise in the general population, recently extended its interest to other team sports besides soccer. The available research supports the importance of recreational team handball, floorball, basketball, touch rugby, futsal and volleyball as training paradigms to improve CV fitness and other health-related variables in inactive individuals across ages and sexes. In most cases, recreational team sports programs assume the form of small-sided games, eliciting mean heart rates of 72-85% of the individual maximal. The majority of the training interventions were carried out for 12weeks with a reported mean attendance of 2 times 40-60min per week. Maximal oxygen uptake improvements were different in magnitude across the recreational team sports, with recreational team handball providing significant and clinically relevant increases (>3.5ml·kg^-1·min^-1). Game format, training exposure and pre-intervention health and fitness status are issues that need further investigation with the aim to optimize recreational team sports exercise programs implementation. Furthermore, the nature and effects of grassroots team sports should be further studied in order to provide as many as possible effective training tools for former practitioners and for the general population that has none or little experience of sport. Given the potential positive impact of recreational team sports practice on world population's health, large-scale randomized controlled trials are warranted.

Effects of a 4 week touch rugby and self-paced interval running intervention on health markers in active young men

Background

Modified team sport activity has been proposed as effective exercise modality for promoting markers of health that are comparable or greater than continuous forms of activity. However, research using modified team sports is currently limited to sedentary populations using 2–3 sessions across a minimum of 8 weeks.

Aim

To investigate the effects of a 4-week touch rugby and self-paced interval running intervention on a range of health markers in active men.

Methods

Sixteen participants (age 26.4 ± 6.4 years) were matched for age, demographic and physical activity before completing a single touch rugby (n = 8) or running (n = 8) session per week for 4 weeks. Measures of systolic and diastolic blood pressure, resting heart rate (RHR), body composition and biochemical status were recorded pre- and post-intervention.

Results

ANCOVA analysis revealed between-group differences for impedance (P = 0.027), fat mass (P = 0.008), percentage body fat (P = 0.008) and fat-free mass (P = 0.002), with greater changes after touch rugby. Systolic blood pressure decreased for both groups with greater reductions observed after touch rugby (P = 0.002). No between-group difference was observed for RHR, interleukin-6 or C-reactive protein (P > 0.05). Contrasting internal, external and perceptual loads were observed.

Conclusion

The results of this study suggest that a single session of touch rugby over a 4-week period elicited greater improvements in body composition and SBP than self-paced running, with both being equally beneficial for improving RHR, diastolic blood pressure and inflammatory status in active young men.

The relationships between rugby union, and health and well-being: a scoping review

OBJECTIVE

To scope the relationships between rugby union, and health and well-being.

DESIGN

Scoping review.

DATA SOURCES

Published and unpublished reports of any age, identified by searching electronic databases, platforms and reference lists.

METHODS

A three-step search strategy identified relevant published primary, secondary studies and grey literature, which were screened using a priori inclusion criteria. Data were extracted using a standardised tool, to form (1) a numerical analysis and (2) a thematic summary.

RESULTS AND DISCUSSION

6658 records were identified, and 198 studies met the inclusion criteria. All forms of rugby union can provide health-enhancing physical activity (PA). 'Non-contact' and wheelchair rugby in particular provide a wide range of physical and mental health and well-being benefits. The evidence is either mixed or unclear in relation to 'contact' rugby union and its effects on a range of physical health domains. Injury and concussion incidence rates are high for contact rugby union relative to other sports.

CONCLUSIONS

A wide range of stakeholders as well as existing and potential participants can use this information to make a more informed decision about participating in and promoting rugby union as a health-enhancing activity. Industry and policy-makers can use this review to inform policies and strategies that look to increase participation rates and use rugby union as a vehicle to contribute positively to population health. Further research understanding rugby union's contribution to PA as well as to muscle-strengthening and balance is indicated, as well as research examining more health and well-being outcomes across more diverse cohorts.

The relationships between rugby union and health: a scoping review protocol

Introduction

Rugby union is played by over eight million people across the world and is considered a form of moderate-to-vigorous physical activity. Consequently, playing rugby may confer health benefits; however, to date, the principal focus of research has been on associated injuries and potential detrimental long-term health sequelae. This protocol outlines the methods behind studying any potential associations between rugby union and both physical and mental health.

Methods and analysis

Best practice methodological frameworks (Arksey and O'Malley, Levac et al and the Joanna Briggs Institute) and previously published scoping review protocols in sport informs the methodology of this protocol. This protocol enables us to map the key concepts and evidence available, summarise and share existing research findings, and identify research gaps in the current literature. A three-step search strategy will identify reviews, original research, and published and grey literature. An initial search will identify suitable search terms, followed by a search using keyword and index terms. Two reviewers will independently screen identified studies for final inclusion.

Dissemination

When publishing the scoping review, we will map key concepts and evidence both numerically and thematically, as well as identify key research priorities for further studies. The review will subsequently be disseminated to stakeholder groups, practitioners and policymakers through a variety of peer-reviewed and non-peer-reviewed publications, conferences and via multimedia platforms.

Principles of Exercise Prescription, and How They Influence Exercise-Induced Changes of Transcription Factors and Other Regulators of Mitochondrial Biogenesis

Physical inactivity represents the fourth leading risk factor for mortality, and it has been linked with a series of chronic disorders, the treatment of which absorbs ~ 85% of healthcare costs in developed countries. Conversely, physical activity promotes many health benefits; endurance exercise in particular represents a powerful stimulus to induce mitochondrial biogenesis, and it is routinely used to prevent and treat chronic metabolic disorders linked with sub-optimal mitochondrial characteristics. Given the importance of maintaining a healthy mitochondrial pool, it is vital to better characterize how manipulating the endurance exercise dose affects cellular mechanisms of exercise-induced mitochondrial biogenesis. Herein, we propose a definition of mitochondrial biogenesis and the techniques available to assess it, and we emphasize the importance of standardizing biopsy timing and the determination of relative exercise intensity when comparing different studies. We report an intensity-dependent regulation of exercise-induced increases in nuclear peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein content, nuclear phosphorylation of p53 (serine 15), and PGC-1α messenger RNA (mRNA), as well as training-induced increases in PGC-1α and p53 protein content. Despite evidence that PGC-1α protein content plateaus within a few exercise sessions, we demonstrate that greater training volumes induce further increases in PGC-1α (and p53) protein content, and that short-term reductions in training volume decrease the content of both proteins, suggesting training volume is still a factor affecting training-induced mitochondrial biogenesis. Finally, training-induced changes in mitochondrial transcription factor A (TFAM) protein content are regulated in a training volume-dependent manner and have been linked with training-induced changes in mitochondrial content.

Cardiometabolic Risk Reduction Through Recreational Group Sport Interventions in Adults: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the pooled effects of community-based, recreational-level group sports on cardiometabolic risk factors and fitness parameters among adults.

PARTICIPANTS AND METHODS

We systematically searched PubMed, EMBASE, PsychINFO, CINAHL, and Web of Science electronic databases for English-language articles reporting the effectiveness of recreational-level group sports published between January 1, 1965, and January 17, 2017. We extracted baseline and end of intervention means for cardiometabolic and fitness parameters. Random- or fixed-effects meta-analyses were used to obtain pooled before and after change in outcome means within intervention participants and between groups.

RESULTS

From 2491 screened titles, 23 publications were included (902 participants; mean ± SD age, 46.6±11.7 years), comprising 21 soccer and 2 rugby interventions. Intervention participants achieved larger improvements (mean [95% CI]) compared with control subjects in weight (-1.44 kg [-1.79 to -1.08 kg]), body mass index (-0.88 kg/m2 [-1.73 to -0.03 kg/m2]), waist circumference (-0.77 cm [-1.21 to -0.33 cm]), body fat (-1.8% [-3.12% to -0.49%]), total cholesterol level (-0.33 mmol/L [-0.53 to -0.13 mmol/L]), low-density lipoprotein cholesterol level (-0.35 mmol/L [-0.54 to -0.15 mmol/L]), systolic blood pressure (-5.71 mm Hg [-7.98 to -3.44 mm Hg]), diastolic blood pressure (-3.36 mm Hg [-4.93 to -1.78 mm Hg]), maximum oxygen consumption (3.93 mL/min per kg [2.96-4.91 mL/min]), and resting heart rate (-5.51 beats/min [-7.37 to -3.66 beats/min]). Most studies (16) were classified as high quality, and we found no evidence of publication bias.

CONCLUSION

We found significant cardiometabolic and fitness improvements following group sport participation, primarily recreational soccer. These findings suggest that group sport interventions are promising strategies for reducing cardiometabolic risk in adults.

Detection of Sirtuin-1 protein expression in peripheral blood leukocytes in dogs

Sirtuin-1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD⁺)-dependent histone deacetylase with a large number of protein substrates. It has attracted a lot of attention in association with extending lifespan. The objective of this study was to enable the evaluation of SIRT1 expression in peripheral blood mononuclear cells (PBMCs) from dogs by flow cytometry. Three transcript variants were amplified from PBMCs by reverse transcription PCR and the nucleotide sequences were analyzed. On the basis of deduced amino acid sequence, a monoclonal antibody against human SIRT1, 1F3, was selected to detect canine SIRT1. Canine SIRT1 in peripheral blood mononuclear cells was successfully detected by western blotting using this antibody. Intracellular canine SIRT1 was also detected in permeabilized 293T cells transfected with a canine SIRT1 expression plasmid by flow cytometry using this antibody. SIRT1 was detected in all leukocyte subsets including lymphocytes, granulocytes and monocytes. The expression level was markedly different among individual dogs. These results indicated that the method applied in this study is useful for evaluating canine SIRT1 levels in PBMCs from dogs.

Similar mitochondrial signaling responses to a single bout of continuous or small-sided-games-based exercise in sedentary men

This study assessed the mitochondrial related signaling responses to a single bout of noncontact, modified football (touch rugby), played as small-sided games (SSG), or cycling (CYC) exercise in sedentary, obese, middle-aged men. In a randomized, crossover design, nine middle-aged, sedentary, obese men completed two, 40-min exercise conditions (CYC and SSG) separated by a 21-day recovery period. Heart rate (HR) and ratings of perceived exertion (RPE) were collected during each bout. Needle biopsies from the vastus lateralis muscle were collected at rest and 30 and 240 min postexercise for analysis of protein content and phosphorylation (PGC-1α, SIRT1, p53, p53Ser15, AMPK, AMPKThr172, CAMKII, CAMKIIThr286, p38MAPK, and p38MAPKThr180/Tyr182) and mRNA expression (PGC-1α, p53, NRF1, NRF2, Tfam, and cytochrome c). A main effect of time effect for both conditions was evident for HR, RPE, and blood lactate ( P < 0.05), with no condition by time interaction ( P > 0.05). Both conditions increased PGC1-α protein and mRNA expression at 240 min ( P < 0.05). AMPKThr172 increased 30 min post CYC ( P < 0.05), with no change in SSG ( P > 0.05). CYC increased p53 protein content at 240 min to a greater extent than SSG ( P < 0.05). mRNA expression of NRF2 decreased in both conditions ( P < 0.05). No condition by time interactions were evident for mRNA expression of Tfam, NRF1, cytochrome c, and p53. The similar PGC-1α response between intensity-matched conditions suggests both conditions are of similar benefit for stimulating mitochondrial biogenesis. Differences between conditions regarding fluctuation in exercise intensity and type of muscle contraction may explain the increase of p53 and AMPK within CYC and not SSG (noncontact, modified football).

Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk: A Cohort Study of Danish Men and Women

BACKGROUND

Cycling is a recreational activity and mode of commuting with substantial potential to improve public health in many countries around the world. The aim of this study was to examine prospective associations between recreational and commuter cycling, changes in cycling habits, and risk of type 2 diabetes (T2D) in Danish adults from the Diet, Cancer and Health cohort study.

METHODS AND FINDINGS

At baseline from 1993 to 1997, 24,623 men and 27,890 women from Denmark, 50-65 y of age and free of T2D and other chronic diseases, underwent a number of assessments, including completing a lifestyle questionnaire also addressing cycling habits. Approximately 5 y later, at a second examination, participants completed a new, updated lifestyle questionnaire. Cox regression was used to estimate hazard ratios (HRs) of incident T2D registered in the Danish National Diabetes Registry, according to recreational and commuter cycling and changes in cycling habits, with adjustment for a priori known T2D risk factors. During 743,245.4 person-years of follow-up (mean follow-up 14.2 y), 6,779 incident cases of T2D were documented. Multivariable adjusted HRs (95% confidence interval [CI]) were 1, 0.87 (0.82, 0.93), 0.83 (0.77, 0.89), 0.80 (0.74, 0.86) and 0.80 (0.74, 0.87) (p for trend = <0.001) for 0, 1-60, 61-150, 151-300, and >300 min/wk of total cycling (recreational and commuter cycling), respectively. In analysis of seasonal cycling, multivariable adjusted HRs (95% CI) were 1, 0.88 (0.83, 0.94), and 0.80 (0.76, 0.85) for non-cyclists, seasonal cyclists (those cycling only in summer or winter), and those cycling during both summer and winter, respectively. How changes in total cycling from baseline to the second examination affected risk was also investigated, and multivariable adjusted HRs (95% CI) were 1, 0.88 (0.78, 1.01), 0.80 (0.69, 0.91), and 0.71 (0.65, 0.77) for non-cyclists and for those who ceased, initiated, or continued cycling between baseline and the second examination, respectively. Lastly, in the analysis of commuter cycling, multivariable HRs (95% CI) were 1, 0.72 (0.60, 0.87), 0.83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend = <0.001) for cycling 0, 1-60, 61-150, and >150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity.

CONCLUSIONS

Commuter and recreational cycling was consistently associated with lower risk of T2D in Danish adults. Our results also provide evidence that late-in-life initiation of or continued engagement in cycling lowers risk of T2D.