Relative Workload Research Articles

Relative workload measurement based on RBRVS theory for village level basic public health service projects

Objective To scientifically measure the workload of basic public health services project on village level. Methods 257 village doctors and 24 public health administrators who work in rural health clinics in Qianjiang city, Hubei province and Qianjiang distrcit, Chongqing city were sampled, with questionnaire survey and key informant in-depth interview methods used to screen basic public health service projects affordable on village level, for workload measurement. Results 35 basic public health service projects were chosen as the measurement projects regarding their relative workload.Hypertension follow-up workload 100 was set as the benchmark, finding the rest relative workload of other projects range from 11 to 936. Conclusions It is reasonable to use the relative value measurement based on RBRVS theory on village level basic public health service projects.Results of this study can support the pricing and further dynamic modification of the basic public health service projects. Key words: Rural health services; Basic public health service project; Resource-based relative value scale; Workload; Measurement

Sex differences in thermoregulation: Implications for physical performance

Following the opening of all roles in the UK Armed Forces to women, there is a requirement for women to operate in more physically demanding roles in more extreme, austere environments, yet our understanding of sex differences in thermoregulation remains limited. Historically, sex differences in thermoregulation have been attributed to anthropometric differences between men and women. However, recent data have highlighted the independent role of sex on thermoregulation. Typically, women will be working at a higher relative intensity than men when performing the same absolute work during military training and operations, and this distinction between relative and absolute workload is important when examining sex differences in the thermoregulatory response to heat and cold.

Testing the efficacy of existing force-endurance models to account for the prevalence of obesity in the workforce

ABSTRACTThis study evaluates whether the existing force-endurance relationship models are predictive of endurance time for overweight and obese individuals, and if not, provide revised models that can be applied for ergonomics practice. Data was collected from 141 participants (49 normal weight, 50 overweight, 42 obese) who each performed isometric endurance tasks of hand grip, shoulder flexion, and trunk extension at four levels of relative workload. Subject-specific fatigue rates and a general model of the force-endurance relationship were determined and compared to two fatigue models from the literature. There was a lack of fit between previous models and the current data for the grip (ICC = 0.8), with a shift toward lower endurance times for the new data. Application of the revised models can facilitate improved workplace design and job evaluation to accommodate the capacities of the current workforce.

Physical activity and 22-year all-cause and coronary heart disease mortality.

This study explores the effects of occupational (OPA) and leisure time physical activity (LTPA) on mortality relative to cardiorespiratory fitness and pre-existing coronary heart disease (CHD). Associations between OPA, measured as energy expenditure (kcal/day) and relative aerobic workload (%VO2 max), LTPA, and 22-year mortality among 1891 Finnish men were assessed by Cox regression models stratified by CHD and adjusted for 19 confounders. In fully adjusted models, each 10% of relative aerobic workload increased all-cause mortality by 13% and CHD mortality 28% (P < 0.01). Compared to healthy subjects, men with CHD experienced lower mortality risks due to OPA and higher risks due to LTPA. While LTPA had no effect among healthy men, in men with CHD each weekly hour of conditioning LTPA increased all-cause mortality risks by 10% and CHD mortality by14%. OPA was positively associated with both all-cause and CHD mortality. LTPA was not protective. Among men with CHD, LTPA increased mortality risks.

The Use of Relative Speed Zones in Australian Football: Are We Really Measuring What We Think We Are?

To examine the difference between absolute and relative workloads, injury likelihood, and the acute:chronic workload ratio (ACWR) in elite Australian football. Single-cohort, observational study. Forty-five elite Australian football players from 1 club participated. Running workloads of players were tracked using Global Positioning System technology and were categorized using either (1)absolute, predefined speed thresholds or (2)relative, individualized speed thresholds. Players were divided into 3 equal groups based on maximum velocity: (1)faster, (2)moderate, or (3)slower. One- and 4-wk workloads were calculated, along with the ACWR. Injuries were recorded if they were noncontact in nature and resulted in "time loss." Faster players demonstrated a significant overestimation of very high-speed running (HSR) when compared with their relative thresholds (P = .01; effect size = -0.73). Similarly, slower players demonstrated an underestimation of high-(P = .06; effect size = 0.55) and very-high-speed (P = .01; effect size = 1.16) running when compared with their relative thresholds. For slower players, (1)greater amounts of relative very HSR had a greater risk of injury than less (relative risk [RR] = 8.30; P = .04) and (2)greater absolute high-speed chronic workloads demonstrated an increase in injury likelihood (RR = 2.28; P = .16), whereas greater relative high-speed chronic workloads offered a decrease in injury likelihood (RR = 0.33; P = .11). Faster players with a very-high-speed ACWR of >2.0 had a greater risk of injury than those between 0.49 and 0.99 for both absolute (RR = 10.31; P = .09) and relative (RR = 4.28; P = .13) workloads. The individualization of velocity thresholds significantly alters the amount of very HSR performed and should be considered in the prescription of training load.

Effect of load carriage and natural terrain conditions on cognitive performance in desert environments

BackgroundCorrect decision making is a critical component of cognitive performance of a soldier, which may be influenced by the load carriage and terrain conditions during their deployment in desert environment. PurposeThe present study was aimed to investigate the effects of loads and terrain conditions on the cognitive performance in a group of twelve healthy heat acclimatized infantry soldiers under natural desert environment. MethodsThe soldiers participated in a 10min walking trial during carrying no load and also carrying 10.7, 21.4 and 30kg at two terrain conditions viz., sandy and hard. We studied attention, memory and executive function, which are having immense functional importance in military operations. Standardized cognitive test battery was applied to the participants after carrying each magnitude of load at each terrain. Baseline cognitive performance was recorded on a separate day and was compared with the performances recorded after the load carriage trials. An attempt was made to reveal the relationship between physiological workload (relative workload) and cognitive performance at the point of completion of load carriage trials. ResultsLoad, terrains and load×terrain interaction did not produce any significant effect (p>0.05) on the cognitive performance. Attention and relative workload were found significantly correlated at hard terrain under no load, 21.4kg and 30kg. Significant correlation was found between executive function and relative workload at hard terrain under no load. ConclusionCarrying upto 30kg load for 10min at 3.5–4kmph walking speed resulted in improvement in attention at sandy terrain, decrement in memory at both sandy and hard terrains and improvement in executive function at sandy terrain.

Workload profiles prior to injury in professional soccer players

ABSTRACTThis study examined if a particular profile of internal and external workload existed prior to injury. Forty-five professional soccer players were monitored over two seasons. For each non-contact injury, a profile of workload variables was determined for 4 weeks and expressed as (i) an absolute, (ii) week-to-week change and (iii) relative to the player’s season mean. Variables included exposure, session rating of perceived exertion (s-RPE) workload, total distance, low-, high-, very-high-speed running distance, mean speed, bodyload, monotony and strain. Acute:chronic workload ratio was also calculated and sensitivity of the relative workload was tested. Absolute and relative exposure and s-RPE workload were greater in all 3 weeks compared to the injury week (P < 0.05). However, no significant differences were evident between the 3 weeks prior to injury for all variables (P > 0.05). Acute:chronic workload ratio for s-RPE was significantly greater than acute:chronic workload ratio for very-high-speed running (P = 0.04). A workload threshold of 114% of a player’s season mean reported low sensitivity and specificity for exposure (25.6[20.2–33.5]% and 73.9[22.6–28.2]%,) and s-RPE workload (16.3[12.6–24.9]% and 79.9[20.3–26.1]%, respectively). No specific load profile existed, although high-sustained exposure and s-RPE were evident for the 3 weeks prior to injury. Consequently, load prescription should be aware of sustained high workloads.

Comparing student, instructor, classroom and institutional data to evaluate a seven-year department-wide science education initiative

We compared seven unrelated data-sets to evaluate a major education improvement initiative. Perceptions of students in 54 course sections were surveyed regarding the helpfulness of 39 specific teaching or learning strategies, and relative workloads and enthusiasm were compared to their other courses. Classes were observed using an established protocol, instructors completed a teaching practices inventory, and their experience with evidence-based pedagogies was established. A graduation exit survey provided longitudinal indications of changes prior to the study, and institutional student ratings of instruction were obtained. This study sought to determine whether improvements were consistently revealed by these data, how perceptions depended upon class size, course improvement model and instructor experience, and whether student ratings captured consistent perceptions about effectiveness. Overall, results compared favourably. Student perceptions and observed effectiveness depended mainly upon class size and improvement strategy. Students found experiences more effective in courses taught by experienced instructors and in classes observed to be more active. Relative workloads were not correlated with any measure of effectiveness while relative enthusiasm was higher in courses perceived to be more effective. Student ratings were consistent with other data-sets, although they did not provide information specific enough for informing further improvements.

Light exercise heart rate on-kinetics: a comparison of data fitted with sigmoidal and exponential functions and the impact of fitness and exercise intensity

This study examined the suitability of sigmoidal (SIG) and exponential (EXP) functions for modeling HR kinetics at the onset of a 5‐min low‐intensity cycling ergometer exercise test (5MT). The effects of training status, absolute and relative workloads, and high versus low workloads on the accuracy and reliability of these functions were also examined. Untrained participants (UT abs; n = 13) performed 5MTs at 100W. One group of trained participants (n = 10) also performed 5MTs at 100W (ET abs). Another group of trained participants (n = 9) performed 5MTs at 45% and 60% V˙O2 max (ET 45 and ET 60, respectively). SIG and EXP functions were fitted to HR data from 5MTs. A 30‐s lead‐in time was included when fitting SIG functions. Functions were compared using the standard error of the regression (SER), and test‐retest reliability of curve parameters. SER for EXP functions was significantly lower than for SIG functions across all groups. When residuals from the 30‐s lead‐in time were omitted, EXP functions only outperformed SIG functions in ET 60 (EXP, 2.7 ± 1.2 beats·min−1; SIG, 3.1 ± 1.1 beats·min−1: P < 0.05). Goodness of fit and test–retest reliability of curve parameters were best in ET 60 and comparatively poor in UT abs. Overall, goodness of fit and test–retest reliability of curve parameters favored functions fitted to 5MTs performed by trained participants at a high and relative workload, while functions fitted to data from untrained participants exercising at a low and absolute workload were less accurate and reliable.

Cardiorespiratory Responses of Adults and Children during Normoxic and Hypoxic Exercise.

We aimed to elucidate potential differential effects of hypoxia on cardiorespiratory responses during submaximal cycling and simulated skiing exercise between adults and pre-pubertal children. Healthy, low-altitude residents (adults, N=13, Age=40±4yrs.; children, N=13, age=8±2yrs.) were tested in normoxia (Nor: PiO2=134±0.4 mmHg; 940 m) and normobaric hypoxia (Hyp: PiO2=105±0.6 mmHg; ~3 000 m) following an overnight hypoxic acclimation (≥12-hrs). On both days, the participants underwent a graded cycling test and a simulated skiing protocol. Minute ventilation (VE), oxygen uptake (VO2), heart rate (HR) and capillary-oxygen saturation (SpO2) were measured throughout both tests. The cycling data were interpolated for 2 relative workload levels (1 W·kg-1 & 2 W·kg-1). Higher resting HR in hypoxia, compared to normoxia was only noted in children (Nor:78±17; Hyp:89±17 beats·min-1; p<0.05), while SpO2 was significantly lower in hypoxia (Nor:97±1%; Hyp:91±2%; p<0.01) with no between-group differences. The VE, VO2 and HR responses were higher during hypoxic compared to normoxic cycling test in both groups (p<0.05). Except for greater HR during hypoxic compared to normoxic skiing in children (Nor:155±19; Hyp:167±13 (beats·min-1); p<0.05), no other significant between-group differences were noted during the cycling and skiing protocols. In summary, these data suggest similar cardiorespiratory responses to submaximal hypoxic cycling and simulated skiing in adults and children.

Optimizing Preseason Training Loads in Australian Football.

To investigate whether preseason training plans for Australian football can be computer generated using current training-load guidelines to optimize injury-risk reduction and performance improvement. A constrained optimization problem was defined for daily total and sprint distance, using the preseason schedule of an elite Australian football team as a template. Maximizing total training volume and maximizing Banister-model-projected performance were bothconsidered optimization objectives. Cumulative workload and acute:chronic workload-ratio constraints were placed on training programs to reflect current guidelines on relative and absolute training loads for injury-risk reduction. Optimization software was then used to generate preseason training plans. The optimization framework was able to generate training plans that satisfied relative and absolute workload constraints. Increasing the off-season chronic training loads enabled the optimization algorithm to prescribe higher amounts of "safe" training and attain higher projected performance levels. Simulations showed that using a Banister-model objective led to plans that included a taper in training load prior to competition to minimize fatigue and maximize projected performance. In contrast, when the objective was to maximize total training volume, more frequent training was prescribed to accumulate as much load as possible. Feasible training plans that maximize projected performance and satisfy injury-risk constraints can be automatically generated by an optimization problem for Australian football. The optimization methods allow for individualized training-plan design and the ability to adapt to changing training objectives and different training-load metrics.

Efficacy of Normobaric Intermittent Hypoxic Training to Improve VO2peak During Acute Hypobaric Hypoxia Exposure

Environmental conditions pose additional threats to the health of soldiers during military operations. Missions conducted at high altitude increase the relative workload for military personnel and unacclimatized warfighters may endure performance decrements. PURPOSE: To examine the effects of normobaric intermittent hypoxic training (NIHT), when compared to normobaric normoxia (NN) training, on peak aerobic capacity (VO2peak) in hypobaric hypoxia (HH). METHODS: Eleven male Reserve Officers’ Training Corps (ROTC) cadets (age 19.55±1.44 y, mass 75.80±8.82 kg, stature 177.45±6.67 cm) completed the 6 week training intervention in either the NIHT (EXP, n=6) or NN (CON, n=5) conditions. Pre- and post-assessment of VO2peak was conducted in an HH setting equivalent to 3033 m. The EXP group also completed a follow-up VO2peak assessment after a 1 week detraining period. Mixed ANOVA was performed to analyze differences between the within-subjects factor (time) and between-subjects factor (group). Repeated measures ANOVA were also performed to analyze differences between the pre-, post-, and follow-up results of the EXP group. RESULTS: There was no significant interaction of time x group, F(1,9)=1.17, P=0.31, partial ή2=0.12, nor significant main effect of group, F(1,9)=0.03, P = 0.86, nor was there a significant main effect of time F(1,9)=3.35, P=0.10, on time-to-exhaustion (TE) measured in HH. Neither was there a significant interaction of time x group for relative VO2peak (RVO2peak), F(1,9)=164, P=0.23, partial ή2=0.15. Further, there was no significant main effect of group for RVO2peak, F(1,9) = 0.61, P=0.45. However, there was a significant main effect of time for RVO2peak, F(1,9)=6.88, P=0.03. Finally, there was no significant difference of RVO2peak in the EXP group between pre-, post-, and follow-up assessments in the HH chamber, F(2,3)=6.53, P=0.06. CONCLUSION: NIHT, compared to NN, failed to elicit significantly greater aerobic endurance enhancements in acute HH. However, while statistical significance for TE, VO2peak, and RVO2peak may not have been attained, moderate effect sizes for the aforementioned variables reveal a potential practical significance was achieved via increases of 7.37%, 15.99%, and 14.71% for the EXP group, respectively. Supported by NSCA Foundation Doctoral Research Grant

Electromyographic and Cardiorespiratory Responses of Load Carriage at Different High Altitudes with Varying Gradients

: Manual load carriage is performed by Indian Army soldiers at different high altitudes (HA) in day to day operation. Such task puts extra stress on cardiorespiratory and skeletomuscular systems. A study was designed to find out the effect of electromyographic and cardiorespiratory responses of load carriage at different high altitudes with varying gradients. Eight healthy Indian infantrymen (mean (± SD) age of 27.2 (± 3.9) years, height of 171.1 (± 2.5) cm, and weight of 66.8 (± 6.7) kg) participated in the study. They were acclimatized at two heights (3550 and 4300 m). On completion of their acclimatization each participant was checked for healthy cardiorespiratory signs and subsequently they walked on a motorized treadmill at a speed of 3.5 km.hr-1 and 0% and 10% gradients under three different experimental load carrying conditions (0, 10.7 and 21.4 kg). Continuous electromyography of three pairs of leg muscles i.e. vastus medialis, gastrocnemius, and tebialis anterior and breath-by-breath recording of oxygen consumption (VO2) and heart rate (HR) were recorded during the experiments. Relative work load (RWL) was calculated from maximum aerobic capacity at respective high altitudes. High altitude had significant effects on the responses of gastrocnemius and vastus medialis muscles as well as on VO2 and RWL. Increased responses of VO2 and leg muscle could be attributed to withstanding the stress of HA and strain of load carriage at steep slopes.

Soldiers\u2019 load carriage performance in high mountains: a physiological study

BackgroundThe present study was designed to evaluate load carriage performance at extremely high altitudes with different loads and walking speeds in terms of physiological evaluation. The degree of maximum oxygen consumption changes at high altitudes was also examined.MethodsTwelve Indian Army soldiers were acclimatized at altitudes of 3,505 m and 4,300 m. They walked for 10 minutes on a motorized treadmill at 2.5 km/h and 3.5 km/h speeds during carrying no loads and three magnitudes of load (10.7 kg, 21.4kg, 30 kg) at both altitudes. Physiological parameters such as oxygen consumption, energy expenditure, heart rate, and ventilation were recorded for each breath using a gas analyzer. The rating of perceived exertion was also noted after each load carriage session. Maximal oxygen consumption (VO2max) was measured at sea level and the two high altitudes, and respective relative workloads (% of VO2max) were calculated from oxygen consumption. Repeated measure ANOVA was applied to reveal the significant effects of the independent variables.ResultsThe participants had significant reductions in VO2max with rising altitude. Marked increases in almost all physiological parameters were observed with increasing load, altitude, and speed. The soldiers expressed heavy perceived exertion levels with higher loads at 3.5 km/h at the two high altitudes.ConclusionsConsidering the physiological responses, expressions of perceived exertion and changes in relative work load at both of the high altitudes Indian soldiers are advised to walk slowly with adequate rest in between their schedules and to carry not more than 32% of their body weight.

Relative individual workload changes may be a risk factor for rerupture of ulnar collateral ligament reconstruction

With an increasing number of Major League Baseball (MLB) players undergoing ulnar collateral ligament (UCL) reconstruction, there remains limited literature on appropriate post-reconstruction workload management to limit the risk of reinjury. A total of 28 MLB pitchers who underwent primary UCL reconstruction surgery and subsequently required revision reconstruction were identified and compared with 137 MLB pitchers who underwent primary reconstruction but did not later require revision surgery. Games pitched, pitch counts, and innings pitched were evaluated and compared 3 years before and after primary reconstruction. Results were then compared between groups. Pitchers who later required revision increased their games pitched by 14.1% after reconstruction whereas the no-revision group pitched 13.6% fewer games than before reconstruction (P < .01). Inning workload was reduced by 9.8% after surgery (89.8 innings after vs 99.6 innings before) for the revision group compared with the no-revision group, which threw 26% fewer innings after surgery (86.3 innings after vs 116.7 innings before) (P = .05). In addition, the revision group pitched 6.6% more pitches after reconstruction, 1138.9 pitches, compared with before reconstruction, 1068.6 pitches. Pitchers who did not require revision, in contrast, pitched 19.6% fewer pitches after reconstruction than before reconstruction (P = .08). This study's findings suggest that MLB pitchers who require revision UCL reconstruction after returning to play following primary UCL reconstruction pitch at or above their pre-primary UCL reconstruction workload whereas control pitchers who do not require revision pitch significantly less, below their pre-primary UCL reconstruction workload.

Physiological Load and Psychological Stress During a 24-hour Work Shift Among Finnish Firefighters.

The aim of this study was to describe physiological load and psychological stress of Finnish firefighters during a 24-hour work shift. R-R intervals were recorded during 24-hour work shifts. Short-time Fourier transform was used to analyze heart rate variability during shifts. HRmean, HRpeak, and square root of the mean of the sum of the squares of the differences between adjacent R-to-R peak intervals of the 24-hour shift was 73 ± 7 bpm (38 ± 4% of HRmax), 156 ± 16 bpm (82 ± 8% of HRmax), and 42 ± 14 ms. Mean VO2 was 11 ± 2 (% of VO2max) and VO2peak 72 ± 11 (% of VO2max). Physiological load and psychological stress were temporarily high, even in young, fit firefighters. As the relative work load may increase and recovery processes slow down among aging employees, fatigue may occur unless work arrangements are well-designed.

Aerobic efficiency is associated with the improvement in maximal power output during acute hyperoxia.

This study investigated the relationship between aerobic efficiency during cycling exercise and the increase in physical performance with acute hyperoxic exposure (FiO2 ~31%) (HOX) and also tested the hypothesis that fat oxidation could be increased by acute hyperoxia. Fourteen males and four females were recruited for two sessions, where they exercised for 2 × 10 min at 100 W to determine efficiency. HOX and normoxia (NOX) were administered randomly on both occasions to account for differences in nitrogen exchange. Thereafter, a progressive ramp test was performed to determine VO2max and maximal power output (W max). After 30 min rest, workload was set to 80% of maximal power output (W max) for a time to exhaustion test (TTE). At 100W gross efficiency was reduced from 19.4% during NOX to 18.9% during HOX (P ≤ 0.0001). HOX increased fat oxidation at 100 W by 52% from 3.41 kcal min‐1 to 5.17 kcal min‐1 (P ≤ 0.0001) with a corresponding reduction in carbohydrate oxidation. W max increased by 2.4% from 388.8 (±82.1) during NOX to 397.8 (±83.5) during HOX (P ≤ 0.0001). SaO2 was higher in HOX both at the end of the maximal exercise test and TTE. Subjects with a high level of efficiency in NOX had a larger improvement in Wmax with HOX, in agreement with the hypothesis that an optimum level of efficiency exists that maximizes power production. No association between mitochondrial excess capacity and endurance performance was found; increases in oxygen supply seemed to increase maximal aerobic power production and maintain/increase endurance capacity at the same relative workload.

Analysis of Electroencephalography Alteration During Sustained Cycling Exercise Using Power Spectrum and Fuzzy Entropy

An electroencephalogram (EEG) is commonly used to study changes in brain activity during exercise. In this study, we used recorded electrocardiography to define the average-to-maximal heart rate ratio (AMHRR) as a gauge of relative exercise workload, and explored how an increase in the AMHRR affected brain activity. EEG signals were recorded from 44 healthy subjects at four scalp sites (i.e., C1, C2, P1, and P2) during 9-min nonstop cycling exercise. The relationships among the AMHRR, EEG spectral power, and EEG fuzzy entropy (FuzzyEn) were established. The EEG spectral power and FuzzyEn results displayed similarly increasing patterns with the AMHRR at all electrodes. However, FuzzyEn exhibited superior specificity in selecting effective frequency bands (i.e., theta, alpha, and beta). The FuzzyEn method can be applied in a wearable device for a human machine interface, which can monitor the EEG during exercise.

Interindividual Variation in the Relationship of Different Intensity Markers—A Challenge for Targeted Training Prescriptions

PurposeTraining intensities are frequently prescribed as relative workloads based on a single reference value (e.g. maximum oxygen uptake). However, exercise-induced physical strain is multifaceted and large interindividual variability in intensity markers has been reported for constant load exercise with standardized relative intensity. This questions the accuracy of (univariate) relative intensities in targeting specific training stimuli. The present trial aims to investigate interindividual variability in the relationship of strain indicators using interpolated performance curves derived from constant load tests at different workloads. This approach enables the prediction of other indicators based on a chosen reference and subsequent comparison of predictive accuracy between group-based and individualized regression models.Methods15 competitive cyclists completed a stepwise incremental cycling test followed by 5 constant load tests with the same absolute workloads as in the stepwise incremental test. The highest of theses workloads which yielded a lactate (BLa) steady state was repeated enabling estimation of intraindividual variability. From constant load tests, the courses of BLa relative to the respective reference value (e.g. %VO2peak) were interpolated by polynomial regression. Variability between individual regression curves was analyzed by mixed modeling. Predictive accuracy was estimated as the sum of squared differences between predicted and observed values.ResultsThe proportion of total variation in the course of BLa relative to the respective reference parameter accounted for by subject identity ranged between 36 and 51%. A significant increase in predictive accuracy was observed for VO2peak and HRmax, respectively, as predicting parameters.ConclusionThese results are in support of a multivariable, individualized approach to intensity prescriptions when aiming at accurately targeted perturbations of homeostasis.

Long Term Effects on Risk Factors for Cardiovascular Disease after 12-Months of Aerobic Exercise Intervention - A Worksite RCT among Cleaners.

ObjectivesOccupational groups exposed to high occupational physical activity have an increased risk for cardiovascular disease (CVD). This may be explained by the high relative aerobic workload. Enhanced cardiorespiratory fitness reduces the relative aerobic workload. Thus, the aim was to evaluate the 12-months effects of worksite aerobic exercise on risk factors for CVD among cleaners.MethodsOne hundred and sixteen cleaners aged 18–65 years were randomized to a group performing aerobic exercise and a reference group receiving lectures. Outcomes were collected at baseline and after 12-months. A repeated measures 2×2 multi-adjusted mixed-model design was applied to compare the between-group differences using intention-to-treat analysis.ResultsBetween-group differences (p<0.05) were found favouring the aerobic exercise group: cardiorespiratory fitness 2.15 (SE 1.03) mlO2/min/kg, aerobic workload -2.15 (SE 1.06) %HRR, resting HR -5.31 (SE 1.61) beats/min, high sensitive C-reactive protein -0.65 (SE 0.24) μg/ml. The blood pressure was unaltered. Stratified analyses on relative aerobic workload at baseline revealed that those with relative aerobic workloads ≥30% of HRR seems to impose a notable adverse effect on resting and ambulatory blood pressure.ConclusionThis long-term worksite aerobic exercise intervention among cleaners led to several beneficial effects, but also potential adverse effects among those with high relative aerobic workloads.Trial RegistrationControlled-Trials.com ISRCTN86682076