Exercise volume and intensity: a dose–response relationship with health benefits Effectiveness of Three Different Walking Prescription Durations on Total Physical Activity in Normal- and Overweight Women Exercise for people with cancer: a clinical practice guideline. Intrapersonal, social and physical environmental determinants of moderate-to-vigorous physical activity in working-age women: a systematic review protocol Effectiveness of exercise interventions on physical function in community-dwelling frail older people: an umbrella review of systematic reviews How Physically Active Are People with Stroke in Physiotherapy Sessions Aimed at Improving Motor Function? A Systematic Review Physical activity as a treatment of non-alcoholic fatty liver disease: A systematic review. Barriers and facilitators to the implementation of physical activity policies in schools: A systematic review. Dose-response relationship between moderate-intensity exercise duration and coronary heart disease risk factors in postmenopausal women. Developing an Intervention to Address Physical Activity Barriers for African–American Women in the Deep South (USA)
Introduction The health benefits of exercise are well established . However , the relationship between exercise volume and intensity and health benefits remains unclear , particularly the benefits of low-volume and intensity exercise . Purpose The primary purpose of this investigation was , therefore , to examine the dose – response relationship between exercise volume and intensity with derived health benefits including volumes and intensity of activity well below international recommendations . Methods Generally healthy , active participants ( n = 72 ; age = 44 ± 13 years ) were assigned r and omly to control ( n = 10 ) or one of five 13-week exercise programs : ( 1 ) 10-min brisk walking 1 × /week ( n = 10 ) , ( 2 ) 10-min brisk walking 3 × /week ( n = 10 ) , ( 3 ) 30-min brisk walking 3 × /week ( n = 18 ) , ( 4 ) 60-min brisk walking 3 × /week ( n = 10 ) , and ( 5 ) 30-min running 3 × /week ( n = 14 ) , in addition to their regular physical activity . Health measures evaluated pre- and post-training including blood pressure , body composition , fasting lipids and glucose , and maximal aerobic power ( VO2max ) . Results Health improvements were observed among programs at least 30 min in duration , including body composition and VO2max : 30-min walking 28.8–34.5 mL kg−1 min−1 , 60-min walking 25.1–28.9 mL kg−1 min−1 , and 30-min running 32.4–36.4 mL kg−1 min−1 . The greater intensity running program also demonstrated improvements in triglycerides . Conclusion In healthy active individuals , a physical activity program of at least 30 min in duration for three sessions/per week is associated with consistent improvements in health status Objective : While there is a dose-response relationship between physical activity ( PA ) and health benefit , little is known about the effectiveness of different PA prescriptions on total daily PA . Aim : To test , under real-life conditions and using an objective , non-invasive measurement technique ( accelerometry ) , the effect of prescribing additional physical activity ( walking only ) of different duration s ( 30 , 60 and 90 min/day ) on compliance ( to the activity prescribed ) and compensation ( to total daily PA ) . Participants in each group were prescribed 5 sessions of walking per week over 4 weeks . Methods : 55 normal-weight and overweight women ( mean BMI 25 ± 5 kg/m2 , height 165 ± 1 cm , weight 68 ± 2 kg and mean age 27 ± 1 years ) were r and omly assigned to 3 prescription groups : 30 , 60 or 90 min/day PA . Results : Walking duration result ed in an almost linear increase in the number of steps per day during the prescription period from an average of about 10,000 steps per day for the 30-min prescription to about 14,000 for the 90-min prescription . Compliance was excellent for the 30-min prescription but decreased significantly with 60-min and 90-min prescriptions . In parallel , degree of compensation subsequent to exercise increased progressively as length of prescription increased . Conclusion : A 30-min prescription of extra walking 5 times per week was well tolerated . However , in order to increase total PA  further , much more than 60 min of walking may need to be prescribed in the majority of individuals . While total exercise ‘ volume ' increased with prescriptions longer than 30 min , compliance to the prescription decreased and greater compensation was evident BACKGROUND Development of this guideline was undertaken by the Exercise for People with Cancer Guideline Development Group , a group organized by Cancer Care Ontario 's Program in Evidence -Based Care ( pebc ) . The purpose of the guideline was to provide guidance for clinicians with respect to exercise for patients living with cancer , focusing on the benefits of specific types of exercise , recommendations about screening requirements for new referrals , and safety concerns . METHODS Consistent with the pebc 's st and ardized approach , a systematic search was conducted for existing guidelines , and systematic literature search es were performed in medline and embase for both systematic review s and primary literature . Content and methodology experts performed an internal review , which was followed by an external review by targeted experts and intended users . RESULTS The search identified three guidelines , eighteen systematic review s , and twenty-nine r and omized controlled trials with relevance to the topic . The present guideline provides recommendations for the duration , frequency , and intensity of exercise appropriate for people living with cancer . It also provides recommendations for pre-exercise assessment , safety concerns , and delivery models . CONCLUSIONS There is sufficient evidence to show that exercise provides benefits in quality of life and muscular and aerobic fitness for people with cancer both during and after treatment , and that it does not cause harm . The present guideline is intended to support the Canadian Society for Exercise Physiology 's Canadian physical activity guidelines . The recommendations are intended for clinicians and institutions treating cancer patients in Ontario , and for policymakers and program planners involved in the delivery of exercise programs for cancer patients Background The majority of North American adult females do not meet current physical activity recommendations ( 150 min of moderate-to-vigorous intensity physical activity ( MVPA ) per week accrued in ≥10 min bouts ) ultimately placing themselves at increased risk of morbidity and mortality . Working-age females face particular challenges in meeting physical activity recommendations as they have multiple dem and s , including occupational , family and social dem and s. To develop effective interventions to increase MVPA among working-age females , it is necessary to identify and underst and the strongest modifiable determinants influencing these behaviours . Therefore , the objective of this systematic review is to examine the available evidence to identify intrapersonal , social and environmental determinants of MVPA among working-age females . Methods / Design Six electronic data bases will be search ed to identify all prospect i ve cohort studies that report on intrapersonal , social and /or environmental determinants of  MVPA  in working-age females . Grey literature sources including theses , published conference abstract s and websites from relevant organizations will also be included . Articles that report on intrapersonal ( e.g. health status , self-efficacy , socio-economic status ( SES ) , stress , depression ) , social environmental ( e.g. crime , safety , area SES , social support , climate and capital , policies ) , and environmental ( e.g. weather , workplace , home , neighbourhood , recreation environment , active transportation ) determinants of MVPA  in a working-age ( mean age 18–65 years ) female population will be included . Risk of bias will be assessed within and across all included studies using the Tool to Assess Risk of Bias in Cohort Studies and the Grade s of Recommendation , Assessment , Development and Evaluation approach . Harvest plots will be used to synthesize results across all determinants , and meta-analyses will be conducted where possible among studies with sufficient homogeneity . Discussion This review will provide a comprehensive examination of evidence in this field and will serve to highlight gaps for future research on the determinants of MVPA in working-age females and ultimately inform intervention design . Systematic review registration PROSPERO : CRD42014009750 Objectives : This umbrella review aim ed to determine the effectiveness of exercise interventions , alone or in combination with other interventions , in improving physical function in community-dwelling older people identified as pre-frail or frail . Introduction : Exercise is said to have a positive impact on muscle mass and strength which improves physical function and hence is beneficial for the treatment of frailty . Several systematic review s discuss the effects of exercise interventions on physical function parameters , such as strength , mobility , gait , balance and physical performance , and indicate that multi-component exercise , including resistance , aerobic , balance and flexibility training , appears to be the best way in which to improve physical function parameters in frail older people . However , there is still uncertainty as to which exercise characteristics ( type , frequency , intensity , duration and combinations ) are the most effective and sustainable over the long-term . Inclusion criteria : Participants were adults , 60 years or over , living in the community and identified as pre-frail or frail . Quantitative systematic review s , with or without meta- analysis that examined the effectiveness of exercise interventions of any form , duration , frequency and intensity , alone or in combination with other interventions design ed to alter physical function parameters in frail older people , were considered . The quantitative outcome measures were physical function , including muscular strength , gait , balance , mobility and physical performance . Methods : An iterative search strategy for ten bibliometric data bases and gray literature was developed . Critical appraisal of seven systematic review s was conducted independently by two review ers using a st and ard Joanna Briggs Institute tool . Data was extracted independently by two review ers using a st and ard Joanna Briggs Institute data extraction tool and summarized using a narrative synthesis approach . Results : Seven systematic review s were included in this umbrella review , with a total of 58 relevant r and omized controlled trials and 6927 participants . Five systematic review s examined the effects of exercise only , while two systematic review s reported on exercise in combination with a nutritional approach , including protein supplementations , as well as fruit and dairy products . The average  exercise frequency was 2–3 times per week ( mean 3.0 ± 1.5 times per week ; range 1–7 weekly ) for 10–90 minutes per session ( mean of 52.0 ± 16.5 mins ) and a total duration of 5–72 weeks with the majority lasting a minimum of 2.5 months ( mean 22.7 ± 17.7 weeks ) . Multi-component exercise interventions can currently be recommended for pre-frail and frail older adults to improve muscular strength , gait speed , balance and physical performance , including resistance , aerobic , balance and flexibility tasks . Resistance training alone also appeared to be beneficial , in particular for improving muscular strength , gait speed and physical performance . Other types of exercise were not sufficiently studied and their effectiveness is yet to be established . Conclusions : Interventions for pre-frail and frail older adults should include multi-component exercises , including in particular resistance training , as well as aerobic , balance and flexibility tasks . Future research should adopt a consistent definition of frailty and investigate the effects of other types of exercise alone or in combination with nutritional interventions so that more specific recommendations can be made Background . Targeted physical activity drives functional recovery after stroke . This review aim ed to determine the amount of time stroke survivors spend physically active during physiotherapy sessions . Summary of Review . A systematic search was conducted to identify published studies that investigated the use of time by people with stroke during physiotherapy sessions . Seven studies were included ; six observational and one r and omised controlled trial . People with stroke were found to be physically active for an average of 60 percent of their physiotherapy session duration . The most common activities practice d in a physiotherapy session were walking , sitting , and st and ing with a mean ( SD ) practice time of 8.7 ( 4.3 ) , 4.5 ( 4.0 ) , and 8.3 ( 2.6 ) minutes , respectively . Conclusion . People with stroke were found to spend less than two-thirds of their physiotherapy sessions duration engaged in physical activity . In light of dosage studies , practice time may be insufficient to drive optimal motor recovery AIM To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease ( NAFLD ) and potential benefits in treating insulin resistance and atherosclerosis . METHODS Medline ( EBSCOhost ) and PubMed were search ed for English- language r and omized controlled trials and prospect i ve cohort studies in human adults aged ≥ 18 which investigated the various effects of exercise alone , a combination of exercise and diet , or exercise and diet coupled with behavioral modification on NAFLD from 2010 to Feburary 2015 . RESULTS Eighteen of 2298 available studies were chosen for critical review , which included 6925 patients . Nine ( 50 % ) studies were r and omized controlled trials . Five ( 27.8 % ) studies utilized biopsy to examine the effects of physical activity on hepatic histology . The most commonly employed imaging modality to determine change in hepatic steatosis was hydrogen-magnetic resonance spectroscopy . Only two studies examined the effects of low impact physical activity for patients with significant mobility limitations and one compared the efficacy of aerobic and resistance exercise . No studies examined the exact duration of exercise required for hepatic and metabolic improvement in NAFLD . CONCLUSION  While exercise improved hepatic steatosis and underlying metabolic abnormalities in NAFLD , more studies are needed to define the most beneficial form and duration of exercise treatment Research consistently indicates that schools fail to implement m and atory physical activity policies . This review aim ed to describe factors ( barriers and facilitators ) that may influence the implementation of school physical activity policies which specify the time or intensity that physical activity should be implemented and to map these factors to a theoretical framework . A systematic search was undertaken in six data bases for quantitative or qualitative studies published between 1995-March 2016 that examined teachers ' , principals ' or school administrators ' reported barriers and /or facilitators to implementing m and ated school physical activity policies .  Two independent review ers screened texts , extracted and coded data from identified articles using the Theoretical Domains Framework ( TDF ) . Of the 10,346 articles identified , 17 studies met the inclusion criteria ( 8 quantitative , 9 qualitative ) . Barriers and facilitators identified in qualitative studies covered 9 and 10 TDF domains respectively . Barriers and facilitators reported in quantitative studies covered 8 TDF domains each . The most common domains identified were : ' environmental context and re sources ' ( e.g. , availability of equipment , time or staff ) , ' goals ' ( e.g. , the perceived priority of the policy in the school ) , ' social influences ' ( e.g. , support from school boards ) , and ' skills ' ( e.g. , teachers ' ability to implement the policy ) . Implementation support strategies that target these factors may represent promising means to improve implementation of  physical activity policies and increase physical activity among school-aged children . Future studies assessing factors that influence school implementation of physical activity policies would benefit from using a comprehensive framework to help identify if any domains have been overlooked in the current literature . REGISTRATION This review was prospect ively registered with PROSPERO ( CRD42016051649 ) on the 8th December 2016 PURPOSE This study was design ed to investigate whether , in a dose-response manner , there would be greater health benefits in a group of postmenopausal women completing 45 minute- vs. 30 minutes of moderate intensity ( 50 % maximal oxygen uptake reserve , VO2R ) exercise 5 days . wk(-1 ) . METHODS Apparently healthy but sedentary postmenopausal women ( n = 33 ) were r and omized to a nonexercise control group , a 30-minute exercise duration group , or a 45-minute exercise duration group . Exercise training was performed 5 days . wk(-1 ) for 12 weeks at 50 % VO2R . Participants were instructed to not change their usual diet throughout the study . RESULTS Twenty-six women completed the study . After 12 weeks , VO2max increased significantly ( p < 0.05 ) in both 30-minute ( 0.20 + /- 0.21 L . min(-1 ) ) and 45-minute ( 0.41 + /- 0.10 L . min(-1 ) ) groups . Repeated measures ANOVA identified a significant interaction between exercise duration and VO2max values ( F = 4.72 , p < 0.05 ) , indicating that VO2max responded differently to 30-minute and 45-minute exercise duration s. Trend analysis showed that body mass , body composition , waist circumference , and high-density lipoprotein cholesterol ( HDL-C ) changed favorably ( p < 0.05 ) across control , 30-minute , and 45-minute groups . CONCLUSIONS Although most health organizations agree that 150 min . wk(-1 ) of physical activity will reduce the risk of all-cause and cardiovascular mortality , few r and omized , controlled studies have examined whether completing more physical activity than the recommended amount will yield additional benefits . Findings from the present study suggest that there is a dose-response relationship between exercise duration and numerous health outcomes in postmenopausal women , including cardiorespiratory fitness , body mass , body composition , waist circumference , and Aim : To address high rates of inactivity and related chronic diseases among African – American women . Material s & methods : Eleven focus groups on physical activity barriers for African – American women in the deep south ( USA ) were conducted ( n = 56 ) . Feedback guided an intervention development process . The result ing Home-Based Individually Tailored Physical Activity Print intervention was vetted with the target population in a 1-month , single arm , pre – post test demonstration trial ( n = 10 ) . Results : Retention was high ( 90 % ) . Intent-to-treat analyses indicated increases in motivational readiness for physical activity ( 70 % of sample ) and physical activity ( 7-day Physical Activity Recall ) from baseline ( mean : 89.5 min/week , st and ard deviation : 61.17 ) to 1 month ( mean : 155 min/week , st and ard deviation : 100.86 ) . Small improvements in fitness ( 6-Min Walk Test ) , weight and psychosocial process measures were also found . Conclusion : Preliminary findings show promise and call for future r and omized controlled trials with larger sample s to determine efficacy . Such low-cost , high-reach approaches to promoting physical activity have great potential for addressing health disparities and benefiting public health
Conclusions The current evidence , from cross-sectional and prospect i ve cohort studies , supports that physical activity of any bout duration is associated with improved health outcomes , which includes all-cause mortality .
Purpose This study aim ed to conduct a systematic literature review to determine whether physical activity episodes of < 10 min in duration have health-related benefits or , alternatively , if the benefits are only realized when the duration of physical activity episodes is ≥10 min .