Cardiorespiratory fitness, cardiovascular workload and risk factors among cleaners; a cluster randomized worksite intervention

The association between number of steps and the ambulatory blood pressure during leisure vs. work hours among cleaners

PURPOSE

The physical activity paradox states occupational physical activity (OPA) to be hazardous and leisure time physical activity (LTPA) to be beneficial for health. Yet, the acute effects of OPA and LTPA on cardiovascular risk factors are sparsely investigated. The aim of this study was to investigate the acute effects on ambulatory blood pressure (ABP) from steps/hour during work and leisure time among cleaners.

METHODS

Data were obtained from a cluster randomized worksite intervention among 91 cleaners in Denmark and included a questionnaire, objective physical measurements, ABP (measured across 24 h), and steps/hour (measured during work and leisure time). A preliminary linear regression analysis was conducted as a mixed model including random intercept and slope, allowing for both within- and between-participant variability. We adjusted for sex, age, job seniority, medication use, smoking, self-reported fitness and BMI. Changes in ABP (mmHg) were estimated per 100 steps/hour.

RESULTS

The number of steps taken was not associated with ABP during either work or leisure. Moreover, the ABP did not seem to differ between exposure to steps taken during work (systolic - 0.42 mmHg, 95% Confidence Interval (CI): - 1.10-0.25, diastolic - 0.03 mmHg, 95% CI, - 0.45-0.39) and leisure time (systolic -0.47 mmHg, 95% CI, - 1.66-0.72, diastolic 0.25 mmHg, 95% CI, - 0.46-0.97).

CONCLUSION

Our findings show no significant association between steps/hour and ABP and no contrasting effects between work and leisure time. These mechanisms fostering the divergent results need to be further investigated to improve the understanding of the physical activity paradox.

An integrated approach to health, wellbeing, and productivity at work: a design of a stepped wedge worksite intervention study

BACKGROUND

Despite an intensive focus on workers' health during recent decades, the prevalence of work-related diseases remains unchanged in Denmark and internationally. Therefore, USA and Australian researchers have initiated new paradigms for integration of health promotion, prevention of work-related disease, and organization of work. Inspired by the Australian WorkHealth Improvement Network program (WIN), this paper describes the background, design, intervention methodologies, and evaluation methods of an Integrated Approach to Health, Wellbeing, and Productivity at Work (ITASPA) intervention aiming to prevent work-related injuries and diseases and promote the health, safety, and wellbeing of the worker.

METHODS

Using a stepped wedge design, worksites will be enrolled at baseline and offered the intervention starting at different times. Data will be collected at baseline, before the off-set of the intervention, and after each implementation period. The effect evaluation will be based on a mixed-methods approach. The qualitative data are based on semi-structured interviews and focus groups. The quantitative data consists of questionnaires, anthropometrics, and resting blood pressure and will be analyzed based on the intention-to-treat principle in linear mixed models with random slope and intercept.

DISCUSSION

Integrated interventions are shown to increase overall health and safety at worksites more effectively and rapidly than more narrowly focused programs. Still, previous integrated interventions are lacking successful implementation. In ITASPA, the effects of the intervention is tested in a strong scientific mixed-methods design. Thus, the ITASPA project contributes to the knowledge about what characterizes a best practice for the implementation of integrated worksite interventions.

TRIAL REGISTRATION

ITASPA is retrospectively registered in Clinicaltrials.gov on May 19, 2023 (NCT05866978).

Comparison of physical workload and physical work capacity among municipality cleaners in Shiraz to determine number of workers needed to counterbalance physical workload

Background

Assessing physical workload is the most important step in deciding whether a workload is high and adopting appropriate control strategies to reduce physical workload. This study aimed to compare physical workload and Physical Work Capacity (PWC) among municipality cleaners in Shiraz to determine the number of workers needed to counterbalance physical workload.

Methods

The present cross-sectional study was performed on 97 municipality cleaners in Shiraz. In the first step, the participants' maximum aerobic capacity (VO₂-max) was estimated in the laboratory using an ergometer bicycle and the Young Men’s Christian Association (YMCA) protocol, based on which the PWC was estimated. Secondly, energy expenditure and heart rate during work were measured using a POLAR400 device in an eight-hour shift. At the end of the work shift, the workers’ perceived physical exertion was assessed using a Rating of Perceived Exertion 6–20 (RPE 6–20) Borg scale. In the final stage, the physical workload was assessed based on the results of the two steps.

Results

The mean VO₂-max of the cleaners and PWC were estimated to be 2.6 ± 0.66 l min⁻¹ and 4.3 ± 1.088 kcal min⁻¹, respectively. The average energy consumed during work was 4.122 ± 1.016 kcal min⁻¹. The overall results of this study showed that physical workload was greater than PWC in 46% of the municipality cleaners. In addition, it was found that 12.45% workforce was required to be added to the street cleaners of Shiraz municipality to reduce the physiological workload on the employed workforce.

Conclusions

With respect to the high level of physical activity in a significant proportion of the cleaners, measures such as increasing the workforce are suggested.

Heart rate during work and heart rate variability during the following night: a day-by-day investigation on the physical activity paradox among blue-collar workers

Objectives:

Contrary to leisure-time physical activity, occupational physical activity (OPA) may have harmful health effects, called the physical activity paradox. A proposed mechanism is that OPA can elevate the heart rate (HR) for several hours per day. We aimed to investigate the association between the mean intensity of OPA and HR variability (HRV) indices the following night.

Methods:

Three cohorts (NOMAD, DPhacto, and Physical Workload and Fitness) involving blue-collar workers from different sectors were merged in this study. HR monitors (Actiheart) recorded 24-hour inter-beat intervals (IBI) for up to four consecutive days. The relative intensity of the mean HR during work was estimated by HR reserve (%HRR), and time-domain indices of HRV were analyzed during the following night. Data were analyzed using a multilevel growth model to test the association between mean %HRR during work and HRV indices at night in a day-by-day analysis adjusted for age, BMI, alcohol consumption, smoking, and occupation.

Results:

The dataset included a sample of 878 Danish blue-collar workers, with a mean %HRR during work of 31%, and 42% worked at an intensity ≥30%HRR. The multilevel model showed negative within- and between-subject associations between %HRR during work and HRV indices at night.

Conclusions:

Our results indicate a higher %HRR during work to associate with lower HRV indices the following night and a higher HR, reflecting an imbalanced autonomic cardiac modulation. This finding supports a high mean HR during work to be a potential underlying mechanism for the harmful health effect of OPA.

Fit to Teach?-Cardiorespiratory Capacity, Vitamin D3, and Ferritin in Physical Education Teachers With Specialization in Dance

ABSTRACT

Schmidt, M, Ohlendorf, D, Groneberg, DA, and Wanke, EM. Fit to teach?-Cardiorespiratory capacity, vitamin D3, and ferritin in physical education teachers with specialization in dance. J Strength Cond Res 35(4): 1156-1164, 2021-Numerous studies have shown that good cardiorespiratory capacity is of great importance for a healthy and long-term professional career as a dancer. Although the cardiorespiratory demands during teaching can reach into the submaximal intensity range, current data on the objective physical fitness of this occupational group are still missing. The aim of this pilot project was to determine selected cardiorespiratory parameters. In addition, measurements of the vitamin D3 (25(OH)D3) and iron balance as well as a subjective assessment of dance teachers' (DTs) fitness were performed. Twenty-one DTs (f: n = 18, m: n = 3) aged 48.2 ± 9.3 years were examined for cardiorespiratory performance within the framework of maximum bicycle spiroergometry. In addition, the self-perception of DTs' fitness was examined as well as the serum vit D3 levels and ferritin concentration in the blood. The cardiorespiratory fitness of DTs can be assessed as average (maximal oxygen consumption, V̇o2max = 29.5 ± 7.1 ml·k-1·min-1; physical working capacity, PWCmax = 165.0 ± 44.4). The DTs seemed to underestimate or overestimate their own capacity. Laboratory diagnostics showed that the 25(OH)D3 levels (21.8 ± 8.5 ng·ml-1) and serum ferritin values (102.4 ± 35.0 g·dl-1) were not optimal for almost the entire sample. In view of the physical occupational requirements, an increase in aerobic cardiorespiratory fitness by endurance-oriented basic training for DTs seems advisable. In addition, the substitution of vit D3 is worth being discussed.

Field Methods to Quantify Emergency Responder Fatigue: Lessons Learned from sUAS Deployment at the 2018 Kilauea Volcano Eruption

OCCUPATIONAL APPLICATIONS There has been increasing use of small unmanned aerial systems in disaster and incident response. We evaluated sUAS pilot states during the tactical response to the 2018 Kilauea Volcano Lower East Rift Zone event, using a 3-minute psychomotor vigilance test (PVT) and wrist worn heart rate sensor. The field data, collected over four days, indicated that the sUAS pilots did not recover to baseline vigilance and physiological levels. Some pilots stopped participating over time, owing to logistical constraints of performing the 3-minute PVT test. Additionally, all pilots refrained from rating their perceived workload levels. We summarize the utility of and challenges associated with collecting performance, physiological, and subjective measures of pilot fatigue during real disaster response.

Factors associated with musculoskeletal symptoms and heart rate variability among cleaners - cross-sectional study

BACKGROUND

The professionals who perform cleaning activity constitute a major economic sector in Brazil. Cleaners may develop health problems related to the musculoskeletal and cardiovascular systems. It is necessary to understand the working and health conditions of cleaners in Brazil. Thus, the aim of this study was to identify factors associated with musculoskeletal symptoms and heart rate variability (HRV) among cleaners.

METHODS

A cross-sectional study conducted at a public higher education institution with 45 outsourced cleaners following approval from the institutional ethics committee. The participants answered a questionnaire addressing sociodemographic, occupational and health data, the Nordic Musculoskeletal Questionnaire, the Physical Activity Questionnaire (work and leisure) and the short version of the Copenhagen Psychosocial Questionnaire. Clinical data (height, body mass, waist-to-hip ratio and blood pressure) and heart rate variability (HRV) were also collected. Logistic and linear regression models were created to identify factors associated with symptoms and HRV.

RESULTS

The sample consisted of women (100%) predominantly older than 50 years of age (44%), without a conjugal life (64%), with three or more children (59%), low educational level (58%) and who worked less than 12 months at the company (87%). Systemic arterial hypertension (23%) was the most reported health problem. The highest frequency of musculoskeletal symptoms was identified in the lower limbs (ankles/feet: 31% in the previous 12 months and 24% in the previous 7 days; knees: 31% in the previous 12 months and 20% in the previous 7 days). Moreover, the workers reported not practicing physical activity during leisure time (84%). Psychosocial aspects indicated health risks for the dimensions "influence at work" (74%), "burnout" (59%) and "stress" (52%). Associations were found between ankle/foot symptoms and body mass index, shoulder symptoms and predictability, and knee symptoms and self-rated health and burnout. HRV indices were associated with age.

CONCLUSIONS

This study outlined the profile of female cleaners and identified risk factors. The workers exhibited musculoskeletal symptoms, which were associated with the body mass index and some psychosocial factors. HRV indices were associated with age. Thus, health promotion and prevention measures should be taken to benefit this population of workers.

Strategies to improve the implementation of workplace-based policies or practices targeting tobacco, alcohol, diet, physical activity and obesity

BACKGROUND

Given the substantial period of time adults spend in their workplaces each day, these provide an opportune setting for interventions addressing modifiable behavioural risk factors for chronic disease. Previous reviews of trials of workplace-based interventions suggest they can be effective in modifying a range of risk factors including diet, physical activity, obesity, risky alcohol use and tobacco use. However, such interventions are often poorly implemented in workplaces, limiting their impact on employee health. Identifying strategies that are effective in improving the implementation of workplace-based interventions has the potential to improve their effects on health outcomes.

OBJECTIVES

To assess the effects of strategies for improving the implementation of workplace-based policies or practices targeting diet, physical activity, obesity, tobacco use and alcohol use.Secondary objectives were to assess the impact of such strategies on employee health behaviours, including dietary intake, physical activity, weight status, and alcohol and tobacco use; evaluate their cost-effectiveness; and identify any unintended adverse effects of implementation strategies on workplaces or workplace staff.

SEARCH METHODS

We searched the following electronic databases on 31 August 2017: CENTRAL; MEDLINE; MEDLINE In Process; the Campbell Library; PsycINFO; Education Resource Information Center (ERIC); Cumulative Index to Nursing and Allied Health Literature (CINAHL); and Scopus. We also handsearched all publications between August 2012 and September 2017 in two speciality journals: Implementation Science and Journal of Translational Behavioral Medicine. We conducted searches up to September 2017 in Dissertations and Theses, the WHO International Clinical Trials Registry Platform, and the US National Institutes of Health Registry. We screened the reference lists of included trials and contacted authors to identify other potentially relevant trials. We also consulted experts in the field to identify other relevant research.

SELECTION CRITERIA

Implementation strategies were defined as strategies specifically employed to improve the implementation of health interventions into routine practice within specific settings. We included any trial with a parallel control group (randomised or non-randomised) and conducted at any scale that compared strategies to support implementation of workplace policies or practices targeting diet, physical activity, obesity, risky alcohol use or tobacco use versus no intervention (i.e. wait-list, usual practice or minimal support control) or another implementation strategy. Implementation strategies could include those identified by the Effective Practice and Organisation of Care (EPOC) taxonomy such as quality improvement initiatives and education and training, as well as other strategies. Implementation interventions could target policies or practices directly instituted in the workplace environment, as well as workplace-instituted efforts encouraging the use of external health promotion services (e.g. gym membership subsidies).

DATA COLLECTION AND ANALYSIS

Review authors working in pairs independently performed citation screening, data extraction and 'Risk of bias' assessment, resolving disagreements via consensus or a third reviewer. We narratively synthesised findings for all included trials by first describing trial characteristics, participants, interventions and outcomes. We then described the effect size of the outcome measure for policy or practice implementation. We performed meta-analysis of implementation outcomes for trials of comparable design and outcome.

MAIN RESULTS

We included six trials, four of which took place in the USA. Four trials employed randomised controlled trial (RCT) designs. Trials were conducted in workplaces from the manufacturing, industrial and services-based sectors. The sample sizes of workplaces ranged from 12 to 114. Workplace policies and practices targeted included: healthy catering policies; point-of-purchase nutrition labelling; environmental supports for healthy eating and physical activity; tobacco control policies; weight management programmes; and adherence to guidelines for staff health promotion. All implementation interventions utilised multiple implementation strategies, the most common of which were educational meetings, tailored interventions and local consensus processes. Four trials compared an implementation strategy intervention with a no intervention control, one trial compared different implementation interventions, and one three-arm trial compared two implementation strategies with each other and a control. Four trials reported a single implementation outcome, whilst the other two reported multiple outcomes. Investigators assessed outcomes using surveys, audits and environmental observations. We judged most trials to be at high risk of performance and detection bias and at unclear risk of reporting and attrition bias.Of the five trials comparing implementation strategies with a no intervention control, pooled analysis was possible for three RCTs reporting continuous score-based measures of implementation outcomes. The meta-analysis found no difference in standardised effects (standardised mean difference (SMD) -0.01, 95% CI -0.32 to 0.30; 164 participants; 3 studies; low certainty evidence), suggesting no benefit of implementation support in improving policy or practice implementation, relative to control. Findings for other continuous or dichotomous implementation outcomes reported across these five trials were mixed. For the two non-randomised trials examining comparative effectiveness, both reported improvements in implementation, favouring the more intensive implementation group (very low certainty evidence). Three trials examined the impact of implementation strategies on employee health behaviours, reporting mixed effects for diet and weight status (very low certainty evidence) and no effect for physical activity (very low certainty evidence) or tobacco use (low certainty evidence). One trial reported an increase in absolute workplace costs for health promotion in the implementation group (low certainty evidence). None of the included trials assessed adverse consequences. Limitations of the review included the small number of trials identified and the lack of consistent terminology applied in the implementation science field, which may have resulted in us overlooking potentially relevant trials in the search.

AUTHORS' CONCLUSIONS

Available evidence regarding the effectiveness of implementation strategies for improving implementation of health-promoting policies and practices in the workplace setting is sparse and inconsistent. Low certainty evidence suggests that such strategies may make little or no difference on measures of implementation fidelity or different employee health behaviour outcomes. It is also unclear if such strategies are cost-effective or have potential unintended adverse consequences. The limited number of trials identified suggests implementation research in the workplace setting is in its infancy, warranting further research to guide evidence translation in this setting.

Effects of 12 months aerobic exercise intervention on work ability, need for recovery, productivity and rating of exertion among cleaners: a worksite RCT

Purpose

This study assessed the effects of a worksite aerobic exercise intervention among cleaners on: work ability, need for recovery, productivity, and rating of exertion.

Methods

In a monocentric randomised controlled trial in Denmark, 116, of 250 invited, cleaners were cluster-randomised (work location; sex; age; length of service) to aerobic exercise [N = 57, 44.9 years, 75.4% female, body mass index (BMI) 26.2], receiving 2 weekly aerobic exercise sessions during 12 months, or a reference group (N = 59, 45.7 years, 76.3% female, BMI 27.1), receiving health-promoting lectures. Self-reported data on outcomes and sociodemographic information were collected at baseline, and at 4 and 12 month follow-up. All outcomes were analysed in a linear repeated-measures 2 × 2 mixed-model by an intention-to-treat analysis approach.

Results

Drop-out was 26 and 33% at 4 and 12 months, respectively. Aerobic exercise adherence was 51% during the first 4 months. At 4 month follow-up no effects were found. At 12 month follow-up, work ability significantly increased by 0.59 on a 0–10 scale (95% CI 0.05–1.13) and need for recovery significantly decreased by − 11.0 on a 0–100 scale (95% CI − 19.8 to − 2.2) in the aerobic exercise group compared to the reference group. Productivity and rating of exertion were unaltered. Analysis stratified on age showed significant effects only among the participants aged ≤ 45 years.

Conclusions

After 12 months work ability improved and need for recovery decreased. A period of 4 months was insufficient to affect these outcomes emphasising that longer interventions may be needed to induce effects on work ability and need for recovery.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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%.

CONCLUSION

OPA was positively associated with both all-cause and CHD mortality. LTPA was not protective. Among men with CHD, LTPA increased mortality risks.

Decrease in musculoskeletal pain after 4 and 12 months of an aerobic exercise intervention: a worksite RCT among cleaners

Background: Prevalence of musculoskeletal pain is high in jobs with high physical work demands. An aerobic exercise intervention targeting cardiovascular health was evaluated for its long term side effects on musculoskeletal pain. Objective: The objective was to investigate if aerobic exercise affects level of musculoskeletal pain from baseline to 4- and 12-months follow-up. Methods: One-hundred-and-sixteen cleaners aged 18–65 years were cluster-randomized. The aerobic exercise group ( n = 57) received worksite aerobic exercise (30 min twice a week) and the reference group ( n = 59) lectures in health promotion. Strata were formed according to closest manager (total 11 strata); clusters were set within strata (total 40 clusters, 20 in each group). Musculoskeletal pain data from eight body regions was collected at baseline and after 4- and 12-months follow-up. The participants stated highest pain in the last month on a scale from 0, stating no pain, up to 10, stating worst possible pain. A repeated-measure 2 × 2 multi-adjusted mixed-models design was applied to compare the between-groups differences in an intention to treat analysis. Participants were entered as a random effect nested in clusters to account for the cluster-based randomization. Results: Clinically significant reductions (>30%, f 2 > 0.25) in the aerobic exercise group, compared to the reference group, in pain intensity in neck, shoulders, arms/wrists were found at 12-months follow-up, and a tendency ( p = 0.07, f 2 = 0.18) to an increase for the knees. At 4-months follow-up the only significant between-group change was an increase in hip pain. Conclusions: This study indicates that aerobic exercise reduces musculoskeletal pain in the upper extremities, but as an unintended side effect may increase pain in the lower extremities. Aerobic exercise interventions among workers standing or walking in the majority of the working hours should tailor exercise to only maintain the positive effect on musculoskeletal pain.

Does Aerobic Exercise Increase 24-Hour Ambulatory Blood Pressure Among Workers With High Occupational Physical Activity?-A RCT

OBJECTIVE

High occupational physical activity (OPA) increases cardiovascular risk and aerobic exercise has been recommended for reducing this risk. This paper investigates the effects of an aerobic exercise intervention on 24-hour ambulatory blood pressure (ABP) among cleaners with high OPA.

METHODS

Hundred and sixteen cleaners between 18 and 65 years were randomized. During the 4-month intervention period, the aerobic exercise group (AE) (n = 57) performed worksite aerobic exercise (2 × 30 minutes/week), while the reference group (REF) (n = 59) attended lectures. Between-group differences in 4-month ABP changes were evaluated by intention-to-treat analysis using a repeated-measure 2 × 2 multiadjusted mixed-models design.

RESULTS

Relative to REF, 24-hour ABP significantly increased in AE: systolic 3.6 mm Hg (95% confidence interval (CI) 1.6–5.7) and diastolic 2.3 mm Hg (95% CI 0.9–3.8). Cleaners with high aerobic workload exhibited particularly high 24-hour ABP increases: systolic 6.0 mm Hg (95% CI 2.4–9.6), and diastolic 3.8 mm Hg (95% CI 1.3–6.4).

CONCLUSION

Aerobic exercise increased 24-hour ABP among cleaners. This adverse effect raises questions about the safety and intended benefits of aerobic exercise, especially among workers with high OPA and a demanding aerobic workload.

http://www.controlled-trials.com/ISRCTN86682076. Unique identifier ISRCTN86682076.

CLINICAL TRIAL REGISTRATION

Trial Number ISRCTN86682076.

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

Objectives

Occupational 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.

Methods

One 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.

Results

Between-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.

Conclusion

This 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 Registration

Controlled-Trials.com ISRCTN86682076

Is aerobic workload positively related to ambulatory blood pressure? A cross-sectional field study among cleaners

PURPOSE

Cardiovascular disease is prevalent among workers with high levels of occupational physical activity. The increased risk may be due to a high relative aerobic workload, possibly leading to increased blood pressure. However, studies investigating the relation between relative aerobic workload and ambulatory blood pressure (ABP) are lacking. The aim was to explore the relationship between objectively measured relative aerobic workload and ABP.

METHODS

A total of 116 cleaners aged 18-65 years were included after informed consent was obtained. A portable device (Spacelabs 90217) was mounted for 24-h measurements of ABP, and an Actiheart was mounted for 24-h heart rate measurements to calculate relative aerobic workload as percentage of relative heart rate reserve. A repeated-measure multi-adjusted mixed model was applied for analysis.

RESULTS

A fully adjusted mixed model of measurements throughout the day showed significant positive relations (p < 0.001): a 1% increase in mean relative aerobic workload was associated with an increase of 0.42 ± 0.05 mmHg (95% CI 0.32-0.52 mmHg) in systolic ABP and 0.30 ± 0.04 mmHg (95% CI 0.22-0.38 mmHg) in diastolic ABP. Correlations between relative aerobic workload and ABP were significant.

CONCLUSIONS

Because workers may have an elevated relative aerobic workload for several hours each working day, this relationship may elucidate a mechanism behind the increased risk for cardiovascular disease among workers exposed to high levels of occupational physical activity.

Aerobic exercise reduces biomarkers related to cardiovascular risk among cleaners: effects of a worksite intervention RCT

Purpose

Blue-collar workers have an increased risk of cardiovascular disease. Accordingly, elevated levels of biomarkers related to risk of cardiovascular disease, such as high-sensitive C-reactive protein, have been observed among blue-collar workers. The objective was to examine whether an aerobic exercise worksite intervention changes the level of inflammation biomarkers among cleaners.

Methods

The design was a cluster-randomized controlled trial with 4-month worksite intervention. Before the 116 cleaners aged 18–65 years were randomized, they signed an informed consent form. The reference group (n = 59) received lectures, and the aerobic exercise group (n = 57) performed worksite aerobic exercise (30 min twice a week). Levels of biomarkers (high-sensitive C-reactive protein, fibrinogen, cholesterol, low- and high-density lipoprotein cholesterol and triglyceride) were collected at baseline and after 4 months. A repeated-measure, multi-adjusted, mixed-model intention-to-treat analysis was applied to compare between-group differences. The study was registered as ISRCTN86682076.

Results

Significant (p < 0.05) between-group reductions from baseline to follow-up were found for high-sensitive C-reactive protein (−0.54 ± 0.20 µg/ml; 95 % CI −0.94, −0.14), low-density lipoprotein cholesterol (−0.32 ± 0.11 mmol/L; 95 % CI −0.54, −0.10) and the ratios of LDL/HDL (−0.30 ± 0.08; 95 % CI −0.46, −0.14), and LDL/TC cholesterol (−0.04 ± 0.02; 95 % CI −0.07, −0.01).

Conclusion

This study indicates that an aerobic exercise intervention among cleaners leads to reduced levels of high-sensitive C-reactive protein and low-density lipoprotein cholesterol, and an unaltered level of fibrinogen. The aerobic exercise seems to improve inflammatory levels and lipoprotein profile among cleaners, with no signs of cardiovascular overload.