title: Undue reliance on I2 in assessing heterogeneity may mislead Does aerobic exercise improve or impair cardiorespiratory fitness and health among cleaners? A cluster randomized controlled trial. Evaluating Intervention Fidelity: An Example from a High-Intensity Interval Training Study Cardiovascular Health Effects of Internet-Based Encouragements to Do Daily Workplace Stair-Walks: Randomized Controlled Trial Effect of individualized worksite exercise training on aerobic capacity and muscle strength among construction workers--a randomized controlled intervention study. Kettlebell training for musculoskeletal and cardiovascular health: a randomized controlled trial. Reliability of the PEDro scale for rating quality of randomized controlled trials. Evaluating the effects of a low volume stairclimbing programme on measures of health-related fitness in sedentary office workers. Walks4Work: assessing the role of the natural environment in a workplace physical activity intervention. Randomised controlled trials – the gold standard for effectiveness research The Effects of Lower Extremity Strengthening Delivered in the Workplace on Physical Function and Work-Related Outcomes Among Desk-Based Workers: A Randomized Controlled Trial
abstract: Background The heterogeneity statistic I2 , interpreted as the percentage of variability due to heterogeneity between studies rather than sampling error , depends on precision , that is , the size of the studies included . Methods Based on a real meta- analysis , we simulate artificially ' inflating ' the sample size under the r and om effects model . For a given inflation factor M = 1 , 2 , 3 , ... and for each trial i , we create a M-inflated trial by drawing a treatment effect estimate from the r and om effects model , using si2MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi = xH8viVGI8Gi = hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY = rqGqVepae9pg0db9vqaiVgFr0xfr = xfr = xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGaem4Cam3aa0baaSqaaiabdMgaPbqaaiabikdaYaaaaaa@2FBE@/M as within-trial sampling variance . Results As precision increases , while estimates of the heterogeneity variance τ2 remain unchanged on average , estimates of I2 increase rapidly to nearly 100 % . A similar phenomenon is apparent in a sample of 157 meta-analyses . Conclusion When deciding whether or not to pool treatment estimates in a meta- analysis , the yard-stick should be the clinical relevance of any heterogeneity present . τ2 , rather than I2 , is the appropriate measure for this purpose OBJECTIVE It is unknown if aerobic exercise overloads or improves the cardiovascular system among workers with high occupational physical activity . This was investigated in a worksite r and omized controlled trial ( RCT ) of aerobic exercise among cleaners . METHODS We r and omized 116 cleaners between 18 - 65 years . The aerobic exercise group ( N=57 ) performed worksite aerobic exercise ( 30 minutes twice a week ) and the reference group ( N=59 ) received lectures .  Cardiorespiratory fitness , blood pressure ( BP ) and diurnal heart rate ( HR ) for measuring aerobic workload [ % HR reserve ( % HRR ) ] were collected at baseline and after four months . A repeated measure 2 × 2 multi-adjusted mixed-model design was applied to compare the between-group differences in an intention-to-treat analysis . RESULTS Between-group differences ( P<0.01 ) were found : cardiorespiratory fitness 2.2 [ st and ard error ( SE ) 0.8 ] ml O 2 × min -1 × kg -1 [ 95 % confidence interval ( 95 % CI ) 0.6 - 3.8 ] , aerobic workload - 3.5 ( SE 1.2 ) % HRR ( 95 % CI - 5.9- -1.0 ) , resting HR -3.8 ( SE 1.2 ) bpm ( 95 % CI -6.1- - 1.4 ) , sleeping HR -3.8 ( SE 1.1 ) bpm ( 95 % CI - 5.9- - 1.7 ) , and systolic BP 3.6 ( SE 1.3 ) mmHg ( 95 % CI 1.1 - 6.0 ) . CONCLUSIONS Worksite aerobic exercise seems to improve cardiorespiratory fitness , aerobic workload , and resting and sleeping HR , but increase systolic BP among cleaners . Beneficial physiological cardiovascular effects are seen from aerobic exercise , but also a harmful effect is evident . Therefore , recommendations should take into consideration the potential cardiovascular overload from additional aerobic exercise on workers with high levels of occupational physical activity Aim Intervention fidelity refers to the degree to which an experimental manipulation has been implemented as intended , but simple , robust methods for quantifying fidelity have not been well documented . Therefore , we aim to illustrate a rigorous quantitative evaluation of intervention fidelity , using data collected during a high-intensity interval training intervention . Design Single-group measurement study . Methods Seventeen adolescents ( mean age ± st and ard deviation [ SD ] 14.0 ± 0.3 years ) attended a 10-week high-intensity interval training intervention , comprising two exercise sessions per week . Sessions consisted of 4 - 7 45-s maximal effort repetitions , interspersed with 90-s rest . We collected  heart rate data at 5-s intervals and recorded the peak heart rate for each repetition . The high-intensity exercise criterion was ≥90 % of individual maximal heart rate . For each participant , we calculated the proportion of total exercise repetitions exceeding this threshold . A linear mixed model was applied to properly separate the variability in peak heart rate between- and within-subjects . Results are presented both as intention to treat ( including missed sessions ) and per protocol ( only participants with 100 % attendance ; n=8 ) . Results For intention to treat , the median ( interquartile range ) proportion of repetitions meeting the high-intensity criterion was 58 % ( 42 % to 68 % ) . The mean peak heart rate was 85 % of maximal , with a between-subject SD of 7.8 ( 95 % confidence interval 5.4 to 11.3 ) percentage points and a within-subject SD of 15.1 ( 14.6 to 15.6 ) percentage points . For the per protocol analysis , the median proportion of high-intensity repetitions was 68 % ( 47 % to 86 % ) . The mean peak heart rate was 91 % of maximal , with between- and within-subject SDs of 3.1 ( -1.3 to 4.6 ) and 3.4 ( 3.2 to 3.6 ) percentage points , respectively . Conclusions Synthesis ing information on exercise session attendance and compliance ( exercise intensity ) quantifies the intervention dose and informs evaluations of treatment fidelity Background Although the hazardous health effects of a sedentary lifestyle are well known , many adults struggle with regular physical activity . Simple and efficient encouragements for increased physical activity are needed . Objective To determine the effect on cardiovascular health of email-based encouragements to do daily stair-walks at work together with colleagues among adults in sedentary occupations . Methods A single-blind r and omized controlled trial was performed at a large administrative company in Copenhagen , Denmark . Participants were 160 office workers ( 125 women , 35 men ; mean age 42 years , SD 10 ; sitting 89.5 % of work time ) . At baseline , aerobic fitness was 37 mL/min/kg ( SD 9 ) , mean blood pressure was 118/79 mmHg ( SD 14/9 ) , and mean body mass index ( BMI ) was 23 kg/m2 ( SD 4 ) . Participants were r and omly assigned ( 2:1 ratio ) to an email group receiving weekly email-based encouragements to walk the stairs for 10 minutes a day or to a control group receiving weekly reminders to continue their usual physical activities . The primary outcome was the change from baseline to 10-week follow-up in aerobic fitness determined from a maximal cycle test . The examiner was blinded to group allocation . Results Adherence to the email encouragements  was fairly high with 82.7 % of the participants performing at least 3 sessions of 10-minute stair-walks per week ( mean 3.3 , SD 1.3 ) . Mean heart rate reached 167 beats/min ( SD 10 ) during stair-walks . In the intention-to-treat analysis , aerobic fitness increased 1.45 mL/min/kg ( 95 % CI 0.64 - 2.27 ) at 10-week follow-up in the email group compared with the control group . In participants with low aerobic fitness at baseline ( n=56 ) , aerobic fitness increased 1.89 mL/min/kg ( 95 % CI 0.53 - 3.24 ) , and systolic and diastolic blood pressure decreased 4.81 mmHg ( 95 % CI 0.47 - 9.16 ) and 2.67 mmHg ( 95 % CI 0.01 - 5.32 ) , respectively , in the email group compared with the control group . Body weight decreased in the email group of those with low aerobic fitness compared with the control group , but this was not statistically significant . Conclusions Simple and inexpensive email-based encouragements to do daily stair-walks together with colleagues at work improves cardiovascular health among adults in sedentary occupations . There exists an enormous potential to prevent the hazardous health effects of a sedentary lifestyle through the use of email-based encouragements to do short bouts of physical activity at the workplace . Trial Registration Clinical trials.gov NCT01293253 ; http:// clinical trials.gov/ct2/show/NCT01293253 ( Archived by WebCite at http://www.webcitation.org/6HWG2jw68 ) OBJECTIVES The combination of high physical work dem and s and low physical capacity has been shown to increase the risk for cardiovascular disease and musculoskeletal disorders . The aim of this study was to assess the physical capacity of construction workers and evaluate the effect of individually tailored exercise programs on their physical fitness and muscular capacity . METHOD The study was a r and omized controlled trial of male constructions workers allocated to either an exercise or control group . The intervention lasted 12 weeks , and the exercise group trained 3 x 20 minutes a week . The participants completed health checks before and after the intervention period . Data from the first health check were used to tailor the exercise in the interventions . RESULTS At baseline , participants had maximal oxygen consumption ( VO(2max ) ) of 2.9 [ st and ard deviation ( SD ) 0.7 ] l/min and body mass index ( BMI ) of 28.3 ( SD 4.7 ) . Compared to representative data on employees in Denmark ( N=78 ) , this study population ( N=67 ) had significantly lower relative aerobic capacity [ difference in z-score -1.13 , st and ard error ( SE ) 0.1 , P<0.001 ] and higher BMI [ difference in z-score 1.10 , SE 0.2 , P<0.001 ] at baseline . With respect to the intervention , group x time analyses showed a significant difference in estimated change in VO(2max)of 0.4 l/min for the exercise group and 0.0 l/min for the control group ( P<0.001 ) . Body mass and other general health measures remained unchanged . CONCLUSION Training for 20 minutes , 3 times a week significantly increased VO(2max)with a clinical ly relevant magnitude regarding risk of cardiometabolic disorders . This study demonstrates a good effectiveness for integrating short exercise bouts into organizational routines among constructions workers OBJECTIVE The aim of this trial was to investigate the effectiveness of a worksite intervention using kettlebell training to improve musculoskeletal and cardiovascular health . METHODS This single-blind r and omized controlled trial involved 40 adults from occupations with a high prevalence of reported musculoskeletal pain symptoms ( mean age 44 years , body mass index 23 kg/m² , 85 % women , with pain intensity of the neck/shoulders 3.5 and of the low back 2.8 on a scale of 0 - 10 ) . A blinded assessor took measures at baseline and follow-up . Participants were r and omly assigned to training -- consisting of ballistic full-body kettlebell exercise 3 times per week for 8 weeks -- or a control group . The main outcome measures were pain intensity of the neck/shoulders and low back , isometric muscle strength , and aerobic fitness . RESULTS Compared with the control group , pain intensity of the neck/shoulders decreased 2.1 points [ 95 % confidence interval ( 95 % CI ) -3.7- -0.4 ] and pain intensity of the low back decreased 1.4 points ( 95 % CI -2.7- -0.02 ) in the training group . Compared with the control group , the training group increased muscle strength of the trunk extensors ( P<0.001 ) , but not of the trunk flexors and shoulders . Aerobic fitness remained unchanged . CONCLUSIONS Worksite intervention using kettlebell training  reduces pain in the neck/shoulders and low back and improves muscle strength of the low back among adults from occupations with a high prevalence of reported musculoskeletal pain symptoms . This type of training does not appear to improve aerobic fitness BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . Despite its obvious advantages , few studies have examined health outcomes of regular stariclimbing . In this study , we investigated the training effects of eight weeks of stairclimbing on recognised measures of health-related fitness in an occupational setting . Forty-five public sector employees ( 22 male , 23 female ) aged 42.3 ± 9.0 years were r and omly assigned to control ( n = 16 ) or stairclimbing  ( n = 29 ) groups . Stairclimbing training began with 1 bout 5d·wk(-1 ) in week 1 , increasing by one climb per day every two weeks until week 5 , where a maintenance level of 3 climbs per day was reached . Participants climbed on staircases located within an 8 storey office block , consisting of 145 steps . The prescribed exercise intensity involved climbing the 8 flights of stairs at a rate of 75 steps·min(-1 ) . All participants agreed not to change their diet or lifestyle over the experimental period . Relative to controls , the stairclimbing group showed a significant increase of 9.4 % in predicted VO2max ( p < 0 . 05 ) . No significant changes in blood pressure , blood lipid concentrations or body composition were noted . These findings provide evidence that stairclimbing can enhance an important component of health-related fitness , namely cardiovascular fitness . Given that such improvement result ed from less than 30 minutes per week of moderate exercise , stairclimbing in the workplace should be promoted as a health-enhancing physical activity . Key pointsLow volumes of stairclimbing significantly increased a key component of cardiorespiratory fitness , namely VO2max . Stairclimbing can therefore be promoted within the typical urban workplace as a health enhancing activity . Indices of morphological or metabolic fitness may require larger volumes of stairclimbing than as prescribed in the current study OBJECTIVES The primary aim of this study was to examine the impact of  physical activity ( PA ) in the natural environment ( eg , " green exercise " ) on resting autonomic function in the Walks4Work intervention . A secondary aim was to assess the feasibility of Walks4Work in terms of adherence , change in PA levels , and cardiovascular health parameters . METHODS In an 8-week r and omized control trial , 94 office workers in an international company were allocated to one of three groups : control , nature ( NW ) , or built ( BW ) lunchtime walking route . Both walking groups were required to undertake two lunchtime walks each week . The NW route centered around trees , maintained grass , and public footpaths . In contrast , the BW consisted of pavement routes through housing estates and industrial areas . Data were collected at baseline and following the intervention . To investigate the impact of the intervention , mixed- design analysis of variance ( ANOVA ) were performed . RESULTS A total of 73 participants completed the intervention ( drop-out rate of 22 % ) . No difference was observed in resting autonomic function between the groups . Self-reported mental health improved for the NW group only . PA levels increased at the intervention mid-point for all groups combined but adherence to the intervention was low with rates of 42 % and 43 % within the BW and NW groups , respectively . CONCLUSION Accompanying a guideline of two active lunchtimes per week with low facilitator input appears inadequate for increasing the number of active lunchtimes and modifying cardiovascular health parameters in an office population . However , this population fell within normal ranges for cardiovascular measures and future research should consider investigating at-risk population s , particularly hypertensive individuals Learning points R and omised controlled trials ( RCTs ) are the reference st and ard for study ing causal relationships between interventions and outcomes as r and omisation eliminates much of the bias inherent with other study design s. To provide a true , reliable assessment of effectiveness , RCTs need to be conducted robustly , i.e. with concealment of allocation , blinding , intention-to-treat analysis and sufficiently large sample size Objective : The aim of this study was to assess the effectiveness of a workplace leg-strengthening program on self-reported function , physical capacity , and work-related outcomes among desk-based workers . Methods : Forty-three desk-based workers were r and omized to a 12-week exercise program or no exercise control . The primary outcome was change in self-reported physical function on the Lower Extremity Functional Scale ( LEFS ) from baseline to follow-up . Secondary outcomes were physical capacity ( mobility , strength ) , self-reported outcomes ( pain , depressive symptoms ) , and work-related outcomes ( resilience , work ability ) . Results : The exercise group showed greater improvements in LEFS and mobility . No significant between-group differences existed in knee strength or remaining self-reported and work-related outcomes . Conclusion : Workplace implemented leg-strengthening exercises are effective at improving self-reported and physical health outcomes of desk-based workers . Moving forward , occupational exercise interventions may be essential to enhance worker longevity among the aging , sedentary workforce
target: Conclusions Workplace-based physical activity interventions consisting of at least moderate-intensity activity improve cardiorespiratory fitness .
  At the present time , we surmise that no single group of employees ( e.g. older employees or less fit individuals ) can be definitively identified as st and ing to benefit more from workplace physical activity interventions than others .
  This demonstrates the potential utility of workplace physical activity interventions for improving cardiorespiratory fitness in a broad range of healthy employees .
background: Background Cardiorespiratory fitness is a strong predictor of all-cause mortality .
  Physical activity of at least moderate intensity can improve cardiorespiratory fitness .
  Workplaces may provide a relatively controlled setting in which to improve cardiorespiratory fitness through physical activity .
  Limited work has been conducted to quantify the impact of delivering physical activity in the workplace on cardiorespiratory fitness .
  Objective The objective of this systematic review was to quantify the effects of workplace physical activity interventions on peak oxygen consumption ( VO2peak ) and explore study and participant characteristics as putative moderators .