How does 6 months of active bike commuting or leisure-time exercise affect insulin sensitivity, cardiorespiratory fitness and intra-abdominal fat? A randomised controlled trial in individuals with overweight and obesity

Is all physical activity equal? Investigating the total and domain-specific relationships between physical activity and cardiometabolic health in U.S. adults (NHANES 2013-2018)

BACKGROUND

Metabolic syndrome (MetS) increases the risk of cardiovascular disease morbidity and mortality. Physical activity (PA) reduces the likelihood of MetS, but it is a complex behavior and is accumulated in multiple domains.

PURPOSE

To cross-sectionally investigate the total and domain-specific relationships between PA and MetS in U.S. adults.

METHODS

Data from 3,408 adults participating in the National Health and Nutrition Examination Survey (2013-2018) were analyzed. Blood pressure (BP), waist circumference (WC), fasting blood glucose (GLU), triglycerides (TRIG), and high-density lipoprotein (HDL) were measured. MetS and its risk factors were the primary and secondary outcomes, respectively. Weekly minutes of total PA and domain-specific PA (i.e., leisure-time (LTPA), transportation (TPA), occupational & household (OHPA)), were self-reported. For each exposure, participants were grouped into weekly PA: (1) 0 min, (2) 1-149 min, (3) 150-299 min, (4) 300-599 min, and (5) 600 + minutes. Logistic regression estimated the odds of having MetS, and its risk factors from PA.

RESULTS

Total PA was associated with lower odds of most MetS risk factors. Compared to no LTPA, and independent of TPA and OHPA, engaging in 150-299 and 300-599 min/week of LTPA was associated with 30% (OR = 0.70 [95%CI: 0.50, 0.98]) and 43% (OR = 0.57 [95%CI: 0.35, 0.92]) lower odds of MetS, respectively. LTPA was also associated with lower odds of having high WC, GLU, TRIG, and low HDL (ORs = 0.52-0.68). Compared to no TPA, and independent of LTPA and OHPA, engaging in 300-599 min/week of TPA was associated with 54% lower odds of MetS (OR = 0.46 [95%CI: 0.25, 0.84]) and 40% lower odds of having a high WC (OR = 0.40 [95%CI: 0.21, 0.76]). Engaging in OHPA was not associated with MetS but was associated with greater odds of having a high WC (OR = 1.44 [95%CI: 1.03, 2.01]), and GLU (ORs = 1.52-1.83), independent of LTPA and TPA.

CONCLUSION

Total PA, seemingly driven by LTPA, was inversely associated with cardiometabolic health. TPA also showcases some protective associations, while OHPA appears to not confer cardiometabolic health benefits. Longitudinal data should confirm these associations using more robust PA measurement tools.

Aerobic Exercise and Weight Loss in Adults: A Systematic Review and Dose-Response Meta-Analysis

Importance

Current guidance on the duration of aerobic exercise recommended in existing guidelines comes primarily from individual trials. Meta-analyses are lacking to examine the dose-response association of aerobic exercise with adiposity measures.

Objective

To clarify the dose-response association of aerobic exercise with adiposity measures.

Data Sources

PubMed, Scopus, the Cochrane Central Register of Controlled Trials, and gray literature sources (ProQuest and ClinicalTrials.gov) from inception to April 30, 2024.

Study Selection

Randomized clinical trials with intervention durations of at least 8 weeks evaluating the effects of supervised aerobic training on adults with overweight or obesity.

Data Extraction and Synthesis

The PRISMA guidelines were followed to report the results of the meta-analysis. Data extraction was conducted by 2 teams of 2 reviewers each, working independently and in duplicate. Random-effects meta-analyses were performed to estimate mean differences and 95% CIs for each 30-minute per week aerobic exercise and to clarify the shape of the curvilinear associations.

Main Outcomes and Measures

Measures of body weight, waist circumference, body fat, adverse events, medication use reduction, and health-related quality of life score. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool, with a range from very low to high certainty.

Results

In total, 116 randomized clinical trials involving 6880 participants (4199 [61%] female; mean [SD] age, 46 [13] years) with overweight or obesity were included. Each 30 minutes per week of aerobic exercise was associated with reduced body weight by 0.52 kg (95% CI, -0.61 to -0.44 kg; n = 109 trials, GRADE = moderate), waist circumference by 0.56 cm (95% CI, -0.67 to -0.45 cm; n = 62 trials, GRADE = high), body fat percentage by 0.37% (95% CI, -0.43% to -0.31%; n = 65 trials, GRADE = moderate), as well as the areas of visceral (mean difference, -1.60 cm2 [95% CI, -2.12 to -1.07 cm2]; n = 26 trials, GRADE = high) and subcutaneous (mean difference, -1.37 cm2 [95% CI, -1.82 to -0.92 cm2]; n = 27 trials, GRADE = moderate) adipose tissues. Aerobic exercise was associated with modestly increased physical (standardized mean difference, 1.69 SD [95% CI, 1.18-2.20 SD]) and mental (standardized mean difference, 0.74 SD [95% CI, 0.29-1.19 SD]) aspects of quality of life (1 trial with 80 participants, GRADE = low). It was associated with modestly increased mild to moderate adverse events, which were mostly musculoskeletal symptoms (risk difference, 2 more events per 100 participants [95% CI, 1 to 2 more]; GRADE = low). Dose-response meta-analyses indicated that body weight, waist circumference, and body fat measures decreased linearly or monotonically in association with increasing duration of aerobic exercise to 300 minutes per week, with aerobic exercise lasting 150 minutes per week at moderate to vigorous intensities resulting in clinically important reductions in waist circumference and body fat.

Conclusions and Relevance

In this meta-analysis of randomized clinical trials, engaging in 30 minutes of aerobic exercise per week was associated with modest reductions in body weight, waist circumference, and body fat measures among adults with overweight or obesity. However, aerobic training exceeding 150 minutes per week at moderate intensity or greater may be needed to achieve clinically important reductions.

Independent and joint associations of estimated cardiorespiratory fitness and its dynamic changes and obesity with the risk of hypertension: A prospective cohort

Our aim was to examine the independent and joint associations of estimated cardiorespiratory fitness (CRF) and its changes and obesity with risk of hypertension in a rural Chinese population. A prospective cohort including 9848 adults without hypertension at baseline was enrolled. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression models. Restricted cubic splines were used to model the dose-response relationship. During 6 years follow-up, 2,019 individuals developed hypertension. A negative association between estimated CRF and hypertension incidence was observed, with the risk being 0.87 (0.84-0.90) per MET increment. For estimated CRF change, the risks of hypertension were 1.50 (1.27-1.77) and 0.75 (0.59-0.97) for decreasers and increasers, respectively, compared to maintainers. Joint analyses showed individuals in the overweight/obesity-fourth quartile of estimated CRF had a 2.08 times higher risk of hypertension than those in the normal weight-first quartile (Pinteraction < 0.05). Those overweight/obesity-decreasers had the highest risk (OR: 2.19, 95%CI: 1.71-2.81; Pinteraction < 0.05) compared to the normal-maintainers. Similar results for abdominal obesity were also observed. Estimated CRF and its dynamic changes showed a negative association with hypertension incidence in the rural Chinese population.

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.

Dose-response effects of exercise and caloric restriction on visceral adiposity in overweight and obese adults: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To determine and compare the dose-response effects of exercise and caloric restriction on visceral adipose tissue in overweight and obese adults, while controlling for the weekly energy deficit induced by the interventions.

METHODS

PubMed, Embase, CINAHL and Web of Science were searched for randomised controlled trials comparing exercise or caloric restriction against eucaloric controls in overweight or obese adults. The primary outcome was the change in visceral fat measured by CT or MRI. Meta-analyses and meta-regressions were performed to determine the overall effect size (ES) and the dose-dependent relationship of exercise and caloric restriction on visceral fat. Heterogeneity, risk of bias and the certainty of evidence were also assessed.

RESULTS

Forty randomised controlled trials involving 2190 participants were included. Overall, exercise (ES -0.28 (-0.37 to -0.19); p<0.001; I2=25%) and caloric restriction (ES -0.53 (-0.71 to -0.35); p<0.001; I2=33%) reduced visceral fat compared with the controls. Exercise demonstrated a dose-response effect of -0.15 ((-0.23 to -0.07); p<0.001) per 1000 calories deficit per week, whereas the effect of caloric restriction was not dose-dependent (ES 0.03 (-0.12 to 0.18); p=0.64). Most of the studies showed a moderate risk of bias.

CONCLUSIONS

These findings support the dose-dependent effects of exercise to reduce visceral fat in overweight and obese adults. Caloric restriction did not demonstrate a dose-response relationship, although this may be attributed to the smaller number of studies available for analysis, compared with exercise studies.

PROSPERO REGISTRATION NUMBER

CRD42020210096.

Effects of prenatal exercise on gestational weight gain, obstetric and neonatal outcomes: FitMum randomized controlled trial

BACKGROUND

To investigate the effects of two different exercise interventions during pregnancy on gestational weight gain (GWG) and obstetric and neonatal outcomes compared to standard care. Additionally, we aimed to improve standardization of GWG measurements by developing a model to estimate GWG for a standardized pregnancy period of 40 weeks and 0 days accounting for individual differences in gestational age (GA) at delivery.

METHODS

In a randomized controlled trial we compared the effects of structured supervised exercise training (EXE) three times per week throughout pregnancy versus motivational counselling on physical activity (MOT) seven times during pregnancy with standard care (CON) on GWG and obstetric and neonatal outcomes. Uniquely, to estimate GWG for a standardized pregnancy period, we developed a novel model to predict GWG based on longitudinally observed body weights during pregnancy and at admission for delivery. Observed weights were fitted to a mixed effects model that was used to predict maternal body weight and estimate GWG at different gestational ages. Obstetric and neonatal outcomes, among them gestational diabetes mellitus (GDM) and birth weight, were obtained after delivery. GWG and the investigated obstetric and neonatal outcomes are secondary outcomes of the randomized controlled trial, which might be underpowered to detect intervention effects on these outcomes.

RESULTS

From 2018-2020, 219 healthy, inactive pregnant women with median pre-pregnancy BMI of 24.1 (21.8-28.7) kg/m² were included at median GA 12.9 (9.4-13.9) weeks and randomized to EXE (n = 87), MOT (n = 87) or CON (n = 45). In total 178 (81%) completed the study. GWG at GA 40 weeks and 0 days did not differ between groups (CON: 14.9 kg [95% CI, 13.6;16.1]; EXE: 15.7 kg [14.7;16.7]; MOT: 15.0 kg [13.6;16.4], p = 0.538), neither did obstetric nor neonatal outcomes. For example, there were no differences between groups in the proportions of participants developing GDM (CON: 6%, EXE: 7%, MOT: 7%, p = 1.000) or in birth weight (CON: 3630 (3024-3899), EXE: 3768 (3410-4069), MOT: 3665 (3266-3880), p = 0.083).

CONCLUSIONS

Neither structured supervised exercise training nor motivational counselling on physical activity during pregnancy affected GWG or obstetric and neonatal outcomes compared to standard care.

TRIAL REGISTRATION

ClinicalTrials.gov; NCT03679130; 20/09/2018.

Effects of acute exercise and exercise training on plasma GDF15 concentrations and associations with appetite and cardiometabolic health in individuals with overweight or obesity - A secondary analysis of a randomized controlled trial

Growth Differentiation Factor 15 (GDF15) is seemingly involved in appetite control. Acute exercise increases GDF15 concentrations in lean humans, but acute and long-term effects of exercise on GDF15 in individuals with overweight/obesity are unknown. We investigated the effects of acute exercise and exercise training on GDF15 concentrations in individuals with overweight/obesity and associations with appetite and cardiometabolic markers. 90 physically inactive adults (20-45 years) with overweight/obesity were randomized to 6-months habitual lifestyle (CON, n=16), or isocaloric exercise of moderate (MOD, n=37) or vigorous intensity (VIG, n=37), 5 days/week. Testing was performed at baseline, 3, and 6 months. Plasma GDF15 concentrations, other metabolic markers, and subjective appetite were assessed fasted and in response to acute exercise before an ad libitum meal. Cardiorespiratory fitness, body composition, insulin sensitivity, and intraabdominal adipose tissue were measured. At baseline, GDF15 increased 18% (95%CI: 4; 34) immediately after acute exercise and 32% (16; 50) 60 min post-exercise. Fasting GDF15 increased 21% (0; 46) in VIG after 3 months (p=0.045), but this attenuated at 6 months (13% (-11; 43), p=0.316) and was unchanged in MOD (11% (-6; 32), p=0.224, across 3 and 6 months). Post-exercise GDF15 did not change in MOD or VIG. GDF15 was not associated with appetite or energy intake. Higher GDF15 was associated with lower cardiorespiratory fitness, central obesity, dyslipidemia, and poorer glycemic control. In conclusion, GDF15 increased in response to acute exercise but was unaffected by exercise training. Higher GDF15 concentrations were associated with a less favorable cardiometabolic profile but not with markers of appetite. This suggests that GDF15 increases in response to acute exercise independent of training state. Whether this has an impact on free-living energy intake and body weight management needs investigation.

Proof of Concept of a 6-Month Person-Oriented Exercise Intervention 'MultiPill-Exercise' among Patients at Risk of or with Multiple Chronic Diseases: Results of a One-Group Pilot Trial

Physical exercise has been shown to be effective in the treatment of non-communicable chronic diseases. However, patients with multiple chronic diseases (multimorbidity) have received little attention in health policy. This pilot trial served as a proof of concept of a 6-months person-oriented exercise intervention for people at risk of or with diagnosed cardiovascular diseases, diabetes mellitus type 2, overweight and/or hip/knee osteoarthritis, regarding effects on health outcomes as well as adherence and safety. The intervention (‘MultiPill-Exercise’) was designed to promote physical exercise participation, considering an individual perspective by addressing personal and environmental factors. Outcomes were assessed at baseline (t0) and after three- (t3) and six-months (t6). The primary outcome was self-reported physical exercise participation in minutes/week comparing t3 and t6 vs. t0. Secondary outcomes included cardio-respiratory fitness (maximum oxygen uptake VO2peak during incremental cycling ergometry), isometric peak torque of knee extensors and flexors, health-related quality of life (Veterans Rand 12 with its subscales of perceived general health (GH), mental health (MCS), and physical health (PCS)) and blood levels. Adherence to exercise (% of attended sessions during the first 12-weeks of the intervention) and adverse events were monitored as well. Data were analyzed using a non-parametric procedure for longitudinal data, estimating rank means (MRank) and relative treatment effects (RTE) as well as linear-mixed effect models for parametric data. The primary endpoint of physical exercise participation was significantly higher at t3 and t6 compared to baseline (t3 vs. t0: MRank = 77.1, p < 0.001, RTE: 0.66; t6 vs. t0: MRank = 70.6, p < 0.001, RTE = 0.60). Improvements at both follow-up time points compared to t0 were also found for relative VO2peak (t3 vs. t0 = 2.6 mL/kg/min, p < 0.001; t6 vs. t0 = 2.0 mL/kg/min, p = 0.001), strength of knee extensors (t3 vs. t0 = 11.7 Nm, p = 0.007; t6 vs. t0= 18.1 Nm, p < 0.001) and GH (t3 vs. t0 = 16.2, p = 0.003; t6 vs. t0 = 13.4, p = 0.008). No changes were found for MCS, PCS and for blood levels. Overall exercise adherence was 77%. No serious adverse events were recorded. Results of this pilot trial represent a first proof of concept for the intervention ‘MultiPill-Exercise’ that will now be implemented and evaluated in a real-world health care setting.

The association of cardiorespiratory fitness and the risk of hypertension: a systematic review and dose-response meta-analysis

Established evidence has indicated a negative correlation between cardiorespiratory fitness (CRF) and hypertension risk. In this study, we performed a meta-analysis to investigate the categorical and dose-response relationship between CRF and hypertension risk and the effects of CRF changes on hypertension risk reduction. The PubMed, Web of Science, and Embase databases were searched for relevant studies. The summarized relative risk (RR) and 95% confidence interval (95% CI) were estimated using the DerSimonian and Laird random effect model, and the dose-response relationship between CRF and hypertension risk was characterized using generalized least-squares regression and restricted cubic splines. Nine cohorts describing 110,638 incident hypertension events among 1,618,067 participants were included in this study. Compared with the lowest category of CRF, the RR of hypertension was 0.63 (95% CI: 0.56-0.70) for the highest CRF category and 0.85 (95% CI: 0.80-0.91) for the moderate category of CRF. For a 1-metabolic equivalent increment in CRF, the pooled RR of hypertension was 0.92 (95% CI: 0.90-0.94) in the total population. The RR of hypertension was 0.71 (95% CI: 0.64-0.79) for participants with CRF increased compared with those whose CRF was decreased over time. In conclusion, our meta-analysis supports the widely held notion of a negative dose-dependent relationship between CRF and hypertension risk.

Maintenance of cardiorespiratory fitness, body composition, and a physically active lifestyle after structured exercise interventions in individuals with overweight and obesity: A mixed-method follow-up study

Objectives

The aim of this mixed-method study was to explore maintenance of physical activity and health effects one year after completion of exercise interventions in transport and leisure-time domains of everyday life. We hypothesised that routinisation of active commuting would lead to better maintenance of physical activity and health effects compared with leisure-time exercise.

Study design

Mixed-methods follow-up study.

Methods

Individuals with overweight/obesity, who completed a 6-month exercise intervention (active commuting by bike (BIKE), moderate (MOD) or vigorous intensity leisure-time exercise (VIG)), were after one year invited to participate in a follow-up visit which included measurements of cardiorespiratory fitness during an incremental bicycle test and body composition using dual-energy X-ray absorptiometry. Variability in maintenance practices was assessed in a sub-sample of participants who experienced the greatest improvements ('VO₂peak improvers') and reductions ('VO₂peak reducers'), respectively, in cardiorespiratory fitness. Semi-structured interviews were conducted (15-30 min) and analysed using systematic text condensation to identify barriers and facilitators associated with maintenance of physical activity.

Results

Out of the 74 participants completing an exercise intervention, 46 (62%) completed follow-up (BIKE: n = 14; MOD: n = 14; VIG: n = 18). Improvements in VO₂peak and reductions in fat mass were maintained in BIKE and VIG. Body weight decreased in BIKE and fat free mass increased in VIG. Changes in VO₂peak and anthropometry at follow-up did not differ between BIKE and MOD + VIG. Fat mass decreased and recreational physical activity increased in 'VO₂peak improvers'. Findings from the interviews suggested that self-monitoring, collective exercising, and new personal exercise challenges facilitate maintenance of a physically active lifestyle.

Conclusion

Completion of a structured exercise intervention consisting of 6 months of active commuting or vigorous intensity leisure-time exercise was associated with long-term maintenance of improvements in VO₂peak and body composition, whereas moderate intensity leisure-time exercise was not. In contrast to our hypothesis, active commuting was not associated with better maintenance of physical activity and health effects after the intervention compared with leisure-time exercise.

Cycling for health: Improving health and mitigating the climate crisis

OBJECTIVE

To review the literature about cycling and health, and to provide an overview and discussion of the available evidence.

SOURCES OF INFORMATION

The MeSH terms bicycle and transportation were searched in PubMed. Clinical trials, practice reviews, and systematic reviews were included. All reference lists were reviewed for additional articles.

MAIN MESSAGE

Climate change is a threat to health. In Canada alone, transportation is the second largest source of greenhouse gas emissions. Active transportation, which is any form of human-powered transportation, can mitigate the health effects of the climate crisis while simultaneously improving the health of people. Physical activity improves overall well-being, as well as physical and mental health. Active transportation, particularly cycling, is a convenient way to meet physical activity targets, reduce risk of disease and all-cause mortality, and derive mental health and social benefits. Family physician advocacy for active transportation has been shown to increase cycling levels in patients compared with no physician advocacy.

CONCLUSION

Family physicians can help to increase the level of active transportation at the individual patient level through patient education and behaviour change counseling; at the community level through community education and political advocacy; and at the policy level through partnerships with larger organizations.

Association of Cycling With All-Cause and Cardiovascular Disease Mortality Among Persons With Diabetes: The European Prospective Investigation Into Cancer and Nutrition (EPIC) Study

Importance

Premature death from all causes and cardiovascular disease (CVD) causes is higher among persons with diabetes.

Objective

To investigate the association between time spent cycling and all-cause and CVD mortality among persons with diabetes, as well as to evaluate the association between change in time spent cycling and risk of all-cause and CVD mortality.

Design, Setting, and Participants

This prospective cohort study included 7459 adults with diabetes from the European Prospective Investigation into Cancer and Nutrition study. Questionnaires regarding medical history, sociodemographic, and lifestyle information were administered in 10 Western European countries from 1992 through 2000 (baseline examination) and at a second examination 5 years after baseline. A total of 5423 participants with diabetes completed both examinations. The final updated primary analysis was conducted on November 13, 2020.

Exposures

The primary exposure was self-reported time spent cycling per week at the baseline examination. The secondary exposure was change in cycling status from baseline to the second examination.

Main Outcomes and Measures

The primary and secondary outcomes were all-cause and CVD mortality, respectively, adjusted for other physical activity modalities, diabetes duration, and sociodemographic and lifestyle factors.

Results

Of the 7459 adults with diabetes included in the analysis, the mean (SD) age was 55.9 (7.7) years, and 3924 (52.6%) were female. During 110 944 person-years of follow-up, 1673 deaths from all causes were registered. Compared with the reference group of people who reported no cycling at baseline (0 min/wk), the multivariable-adjusted hazard ratios for all-cause mortality were 0.78 (95% CI, 0.61-0.99), 0.76 (95% CI, 0.65-0.88), 0.68 (95% CI, 0.57-0.82), and 0.76 (95% CI, 0.63-0.91) for cycling 1 to 59, 60 to 149, 150 to 299, and 300 or more min/wk, respectively. In an analysis of change in time spent cycling with 57 802 person-years of follow-up, a total of 975 deaths from all causes were recorded. Compared with people who reported no cycling at both examinations, the multivariable-adjusted hazard ratios for all-cause mortality were 0.90 (95% CI, 0.71-1.14) in those who cycled and then stopped, 0.65 (95% CI, 0.46-0.92) in initial noncyclists who started cycling, and 0.65 (95% CI, 0.53-0.80) for people who reported cycling at both examinations. Similar results were observed for CVD mortality.

Conclusion and Relevance

In this cohort study, cycling was associated with lower all-cause and CVD mortality risk among people with diabetes independent of practicing other types of physical activity. Participants who took up cycling between the baseline and second examination had a considerably lower risk of both all-cause and CVD mortality compared with consistent noncyclists.

Effect of different types of regular exercise on physical fitness in adults with overweight or obesity: Systematic review and meta-analyses

This systematic review examined the effect of exercise training interventions on physical fitness in adults with overweight or obesity and compared the effectiveness of different types of exercise training. Four electronic databases were searched. Articles were included if they described randomized controlled trials of exercise training interventions and their effect on maximal oxygen consumption or muscle strength in adults with overweight or obesity. Changes in outcome parameters were analyzed using random effects meta-analyses for different training types (aerobic, resistance, combined aerobic plus resistance, and high-intensity interval training). Eighty-eight articles satisfied the inclusion criteria of which 66 (3964 participants) could be included in the meta-analyses. All training types increased VO_2max (mean difference 3.82 ml/min/kg (95% CI 3.17, 4.48), P < 0.00001; I² = 48%). In direct comparisons, resistance training was less effective in improving VO_2max than aerobic training, HIIT was slightly more effective than aerobic training, and no difference between aerobic and combined aerobic plus resistance training was found. For muscle strength benefits, incorporation of resistance exercise in the training program is indicated. Exercise training increases VO_2max and muscle strength in adults with overweight or obesity. Differences between training types should be weighed with other needs and preferences when health professionals advise on exercise training to improve physical fitness.

Insulin-mediated muscle microvascular perfusion and its phenotypic predictors in humans

Insulin increases muscle microvascular perfusion and enhances tissue insulin and nutrient delivery. Our aim was to determine phenotypic traits that foretell human muscle microvascular insulin responses. Hyperinsulinemic euglycemic clamps were performed in 97 adult humans who were lean and healthy, had class 1 obesity without comorbidities, or controlled type 1 diabetes without complications. Insulin-mediated whole-body glucose disposal rates (M-value) and insulin-induced changes in muscle microvascular blood volume (ΔMBV) were determined. Univariate and multivariate analyses were conducted to examine bivariate and multivariate relationships between outcomes, ΔMBV and M-value, and predictor variables, body mass index (BMI), total body weight (WT), percent body fat (BF), lean body mass, blood pressure, maximum consumption of oxygen (VO2max), plasma LDL (LDL-C) and HDL cholesterol, triglycerides (TG), and fasting insulin (INS) levels. Among all factors, only M-value (r = 0.23, p = 0.02) and VO2max (r = 0.20, p = 0.047) correlated with ΔMBV. Conversely, INS (r = - 0.48, p ≤ 0.0001), BF (r = - 0.54, p ≤ 0.001), VO2max (r = 0.5, p ≤ 0.001), BMI (r = - 0.40, p < 0.001), WT (r = - 0.33, p = 0.001), LDL-C (r = - 0.26, p = 0.009), TG (r = - 0.25, p = 0.012) correlated with M-value. While both ΔMBV (p = 0.045) and TG (p = 0.03) provided significant predictive information about M-value in the multivariate regression model, only M-value was uniquely predictive of ΔMBV (p = 0.045). Thus, both M-value and VO2max correlated with ΔMBV but only M-value provided unique predictive information about ΔMBV. This suggests that metabolic and microvascular insulin responses are important predictors of one another, but most metabolic insulin resistance predictors do not predict microvascular insulin responses.

Effect of exercise training on skeletal muscle protein expression in relation to insulin sensitivity: Per-protocol analysis of a randomized controlled trial (GO-ACTIWE)

Exercise training improves peripheral insulin sensitivity and leads to molecular adaptations in the skeletal muscle. We investigated changes in the expression of key muscle proteins in the glucose metabolic pathway following active commuting by bike or leisure-time exercise at two different intensities. In addition, potential associations between insulin sensitivity and muscle protein expression were examined. This per-protocol analysis included 72 out of 130 physically inactive, healthy women and men (20-45 years) with overweight/obesity (BMI: 25-35 kg/m2 ) who completed 6 months of no intervention (CON, n = 12), active commuting by bike (BIKE, n = 14), or leisure-time exercise of moderate (MOD, n = 28) or vigorous (VIG, n = 18) intensity. Exercise was prescribed 5 days/week with a weekly exercise energy expenditure of 1,600 kcal for women and 2,100 kcal for men. Insulin sensitivity was determined by a hyperinsulinemic euglycemic clamp and skeletal muscle biopsies were obtained from m. vastus lateralis and analyzed for protein expression at baseline and after 3 and 6 months of intervention. We found an increased expression of pyruvate dehydrogenase (PDH) in the exercise groups compared with the control group following 6 months of training. No differential effects were observed on the protein expression following moderate versus vigorous intensity exercise. In addition, we found a positive association between insulin sensitivity and the expression of glucose transporter type 4 as well as PDH. The positive association and the increase in expression of PDH after exercise training points toward a role for PDH in the training-induced enhancement of insulin sensitivity.

Health effects of active commuting to work: The available evidence before GISMO

Sedentary lifestyle is a major modifiable risk factor for many chronic diseases. Global guidelines recommend for maintaining health in adults, at least 150 minutes of moderate intensity of physical activity throughout the week, but compliance is insufficient and health problems arise. One obvious way to overcome this is to integrate physical activity into the daily routine for example by active commuting to work. Scientific evidence, however, is scarce and therefore we set out to perform this systematic review of the available literature to improve understanding of the efficiency of active commuting initiatives on health. Literature searches were performed in PubMed and Cochrane database. Altogether, 37 studies were screened. Thereof, eight publications were reviewed, which included 555 participants. The mean study duration of the reviewed research was 36 ± 26 (8-72) weeks. Overall, active commuting in previously untrained subjects of both sexes significantly improved exercise capacity, maximal power, blood pressure, lipid parameters including cholesterol, high-density lipoprotein, and waist circumference. Improvement was independent of the type of active commuting. Despite relatively few studies that were previously performed, this review revealed that active commuting has health beneficial effects comparable to those of moderate exercise training.

Associations of early-life exposure to famine with abdominal fat accumulation are independent of family history of diabetes and physical activity

The present study aimed to investigate the association of early-life exposure to famine with abdominal fat accumulation and function and further evaluate the influence of first-degree family history of diabetes and physical activity on this association. The present work analysed parts of the REACTION study. A total of 3033 women were enrolled. Central obesity was defined as waist circumferences (W) ≥ 85 cm. Chinese visceral adiposity index (CVAI) was used to evaluate visceral adipose distribution and function. Partial correlation analysis showed BMI, W, glycated Hb and CVAI were associated with early-life exposure to famine (both P < 0·05). Logistic regression showed that the risks of overall overweight/obesity and central obesity in fetal, early-childhood, mid-childhood and late-childhood exposed subgroups were increased significantly (all P < 0·05). Compared with the non-exposed group, the BMI, W and CVAI of fetal, early- to late-childhood exposed subgroups were significantly increased both in those with or without first-degree family history of diabetes and in those classified as physically active or inactive, respectively (all P < 0·05). The associations of BMI, W and CVAI with early-life exposure to famine were independent of their associations with first-degree family history of diabetes (all P < 0·01) or physical activity status (all P < 0·001). Early-life exposure to famine contributed to abdominal fat accumulation and dysfunction, which was independent of the influence of genetic background and exercise habits. Physical activity could serve as a supplementary intervention for women with high risk of central obesity.

Effectiveness of a 3-Month Mobile Phone-Based Behavior Change Program on Active Transportation and Physical Activity in Adults: Randomized Controlled Trial

BACKGROUND

Active transportation (AT; ie, walking and cycling as a mode for transportation) has been associated with decreased morbidity and mortality; however, low-cost and scalable intervention programs are lacking.

OBJECTIVE

The goal of the research was to determine the effectiveness of a 3-month behavior change program delivered via a mobile phone app to promote AT (TravelVu Plus) on time spent in moderate-to-vigorous physical activity (MVPA).

METHODS

For this 2-arm parallel randomized controlled trial, we recruited a population-based sample of 254 adults from Stockholm County who were aged 20 to 65 years and had access to a smartphone. On completion of 1-week baseline measures, the 254 participants were randomized to either the control or intervention group (1:1 ratio). Both groups had access to the standard TravelVu app (Trivector AB) for monitoring their AT for 6 months. The intervention group also received a 3-month behavior change program to promote AT (TravelVu Plus app). Assessors of outcomes were blinded to group allocation. Outcomes were objectively measured MVPA at 3 (primary) and 6 months. Secondary outcomes were AT, attitudes toward AT, and health-related quality of life at 3 and 6 months.

RESULTS

No effect on MVPA was observed after 3 months (P=.29); however, at 6 months the intervention group had a greater improvement in MVPA than the controls (6.05 minutes per day [95% CI 0.36 to 11.74; P=.04]). A Bayesian analyses showed that there was a 98% probability that the intervention had any effect at 6 months, and a 63% probability that this effect was >5 minute MVPA per day.

CONCLUSIONS

No effect on MVPA immediately after the intervention period (at 3 months) was observed; however, there was a delayed effect on MVPA (6 minutes per day) at 6 months, which corresponds to approximately 30% of the weekly MVPA recommendation. Our findings suggest that a behavior change program promoting AT delivered via an app may have a relevant effect on PA.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03086837; https://clinicaltrials.gov/ct2/show/NCT03086837.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s12889-018-5658-4.

Association between Different Modes of Travelling and Adiposity in Chilean Population: Findings from the Chilean National Health Survey 2016-2017

BACKGROUND

Active travel has been suggested as a feasible way of increasing physical activity levels. Although international studies have demonstrated its effect over different health outcomes and adiposity, there is still limited evidence on this topic in developing countries, such as Chile.

AIM

To investigate the associations between different types of travelling and markers of obesity in the Chilean adult population.

METHODS

5411 participants from the Chilean National Health Survey 2016-2017 (CNHS) were included in this study. Active travel was assessed using a questionnaire. Car commuters, public transport (PT), walking and cycling were the four forms of travelling assessed. Bodyweight, body mass index and waist circumference were used as markers of adiposity.

RESULTS

Compared to car travellers, body weight, WC and BMI levels were lower for PT walking and cycling travellers. The odds for obesity (Odds ratio (OR): 0.41 (95% CI: 0.28; 0.61 p ≤ 0.001) were lower for walking and the odds (OR: 0.56 (95%CI: 0.35; 0.89 p = 0.014) for central obesity were significantly lower for cyclist in comparison to car travellers. Additionally, participation in any form of active travel (walking or cycling) was low, with only 20.9% of the population reporting being active travellers.

CONCLUSION

Active travel, such as walking and cycling, was associated with lower adiposity levels in the Chilean adult population. Promoting active travel could be a feasible strategy to tackle the high prevalence of obesity and physical inactivity in the Chilean population.

Effects of active commuting on cardiovascular risk factors: GISMO-a randomized controlled feasibility study

A sedentary lifestyle is a major modifiable risk factor for many chronic diseases. Lifestyle modification in order to increase exercise capacity is key in the prevention and rehabilitation of chronic diseases. This could be achieved by active commute. The aim of this study was to assess the effects of daily active commuting on physical activity (PA) and exercise capacity. Seventy‐three healthy hospital employees (age: 46 ± 9 years, 38% male), with a predominantly passive way of commuting, were randomly assigned to two parallel groups, a control group (CG, N = 22) or an intervention group (IG, N = 51), which was further split into public transportation/active commuting (IG‐PT, N = 25) and cycling (IG‐C, N = 26). Both intervention groups were asked to reach 150 min/wk of moderate‐ to vigorous‐intensity exercise during their commute for 1 year. CG maintained a passive commuting mode. All participants underwent assessment of anthropometry, risk factor stratification, and exercise capacity by a medical doctor at the Institute of Sports Medicine, Prevention and Rehabilitation. Weekly physical activity, using the International Physical Activity Questionnaire and commuting behavior, using an online diary, were used to assess physical activity. At the end of the study, the change in exercise capacity did significantly differ between IG and CG (P = .003, ES = 0.82). Actively covered distances through commuting significantly differed between groups (walking P = .026; cycling P < .001). Therefore, active commuting improves exercise capacity and can be recommended to the working population to increase exercise capacity.

Effects of active commuting to work for 12 months on cardiovascular risk factors and body composition

Active commuting has the potential to decrease cardiovascular risk by increasing physical activity. We aimed to investigate the effects of active commuting to work for 12 months on body composition and cardiovascular risk factors. Therefore, 73 hospital employees (age: 46 ± 9 years, 36% males), with a predominantly passive way of commuting, were randomly assigned to an intervention group (IG) and a control group (CG) in a 2:1 fashion. The IG was further divided into a public transportation plus active commuting group (IG‐PT) and a cycling group (IG‐C). Both IGs were prompted to reach 150 min/wk of moderate intensity exercise. Daily self‐reported commuting details were verified by GPS tracking. All subjects underwent assessment of body composition, resting blood pressure, glycemic control, and lipid profile at the beginning and end of the study. Data for final analyses were available in 62 subjects. Commuting details indicated that the subjects randomized to IG changed their commuting habits. HbA1c decreased by 0.2% [95%CI: −0.3, −0.2] in IG‐PT but was not statistically different between groups (P = .06). LDL cholesterol decreased in IG‐C by 0.8 mmol/L [−1.1, −0.4] and by 0.6 mmol/L [−1.2, 0.1] in IG‐PT which can be considered biologically relevant but did not yield statistical significance. Body composition and blood pressure did not differ between groups. Active commuting to work for 12 months did not change body composition but yielded relevant changes in lipid profile and glycemic control. Health benefits of active commuting should be addressed by healthcare professionals when counseling individuals that seek to improve their cardiovascular risk profile.

Active Commuting and Physical Fitness: A Systematic Review

Physical fitness (PF) is considered an excellent biomarker of health. One possible strategy to improve PF levels is active commuting. This review, performed accordingly to the Preferred Reporting Items for Systematic Reviews guidelines includes scientific articles published in peer-reviewed journals up to December 2019 that aim at examining the relationship between active travel/commuting and PF. The search was performed in three databases (PubMed, Scopus, and Web of Science). Sixteen studies were included in this review. Findings from the 16 studies were unclear. From the eleven studies on children and adolescents screened, eight were cross-sectional, one prospective cohort, one quasi-experimental, and one experimental. From the five studies on adults, four were experimental and one cross-sectional. Body mass, waist circumference, skinfolds, fat mass, cardiorespiratory fitness, upper and lower strength tests were performed in children, adolescents, and adults. Agility and speed tests were performed only in the young age groups. Majority of the investigations on young ages and adults have shown positive effects or relationships between active commuting and several attributes of PF. However, to avoid misconceptions, there is a need for future robust investigation to identify potential mediators or confounders in this relationship. More robust investigations are essential to understand how and whether decision-makers and public health authorities can use active travel/commuting as a strategy to improve PF in all ages.

Association of injury related hospital admissions with commuting by bicycle in the UK: prospective population based study

OBJECTIVE

To determine whether bicycle commuting is associated with risk of injury.

DESIGN

Prospective population based study.

SETTING

UK Biobank.

PARTICIPANTS

230 390 commuters (52.1% women; mean age 52.4 years) recruited from 22 sites across the UK compared by mode of transport used (walking, cycling, mixed mode versus non-active (car or public transport)) to commute to and from work on a typical day.

MAIN OUTCOME MEASURE

First incident admission to hospital for injury.

RESULTS

5704 (2.5%) participants reported cycling as their main form of commuter transport. Median follow-up was 8.9 years (interquartile range 8.2-9.5 years), and overall 10 241 (4.4%) participants experienced an injury. Injuries occurred in 397 (7.0%) of the commuters who cycled and 7698 (4.3%) of the commuters who used a non-active mode of transport. After adjustment for major confounding sociodemographic, health, and lifestyle factors, cycling to work was associated with a higher risk of injury compared with commuting by a non-active mode (hazard ratio 1.45, 95% confidence interval 1.30 to 1.61). Similar trends were observed for commuters who used mixed mode cycling. Walking to work was not associated with a higher risk of injury. Longer cycling distances during commuting were associated with a higher risk of injury, but commute distance was not associated with injury in non-active commuters. Cycle commuting was also associated with a higher number of injuries when the external cause was a transport related incident (incident rate ratio 3.42, 95% confidence interval 3.00 to 3.90). Commuters who cycled to work had a lower risk of cardiovascular disease, cancer, and death than those who did not. If the associations are causal, an estimated 1000 participants changing their mode of commuting to include cycling for 10 years would result in 26 additional admissions to hospital for a first injury (of which three would require a hospital stay of a week or longer), 15 fewer first cancer diagnoses, four fewer cardiovascular disease events, and three fewer deaths.

CONCLUSION

Compared with non-active commuting to work, commuting by cycling was associated with a higher risk of hospital admission for a first injury and higher risk of transport related incidents specifically. These risks should be viewed in context of the health benefits of active commuting and underscore the need for a safer infrastructure for cycling in the UK.

Exercise-Induced Adaptations to Adipose Tissue Thermogenesis

Exercise training results in beneficial adaptations to numerous tissues and offers protection against metabolic disorders including obesity and type 2 diabetes. Multiple studies have indicated that both white (WAT) and brown (BAT) adipose tissue may play an important role to mediate the beneficial effects of exercise. Studies from both rodents and humans have identified exercise-induced changes in WAT including increased mitochondrial activity and glucose uptake, an altered endocrine profile, and in rodents, a beiging of the WAT. Studies investigating the effects of exercise on BAT have resulted in conflicting data in terms of mitochondrial activity, glucose uptake, and thermogenic activity in rodents and humans, and remain an important area of investigation. This review discusses the exercise-induced adaptations to white and brown adipose tissue, distinguishing important differences between rodents and humans and highlighting the latest studies in the field and their implications.

Are Moderate and Vigorous Leisure-Time Physical Activity Associated With Musculoskeletal Pain? A Cross-Sectional Study Among 981 Physical Therapists

PURPOSE

Musculoskeletal pain (MP) is common among workers, especially for health-care professionals. Paradoxically, many of those rehabilitating patients for pain-that is, physical therapists (PTs)-also have pain. Adequate levels of physical activity are recommended for cardiovascular and musculoskeletal health. However, the association between physical activity and MP among PTs remains unknown. This study aims to determine the association between moderate and vigorous leisure-time physical activity levels and MP in PTs.

DESIGN

Cross-sectional study.

SETTING

Workplace.

PARTICIPANTS

Nine hundred eighty-one PTs.

MEASURES

Data on MP and leisure-time physical activity were collected using an online survey.

ANALYSIS

The odds for having lower level of MP as a function of physical activity were estimated using binary logistic regression controlled for various confounders.

RESULTS

Performing ≥75 min/week of vigorous leisure-time physical activity increased the odds of experiencing lower levels of neck-shoulder pain (odds ratio = 1.43, 95% confidence interval, 1.05-1.94). No association was found neither between vigorous nor between moderate leisure-time physical activity and MP in the arm-hand or back.

CONCLUSION

Performing ≥75 min/week of vigorous leisure-time physical activity is associated with lower levels of MP in neck and shoulders among PTs. No associations were found between vigorous or moderate leisure-time physical activity and MP in arm-hand and back.