TY - BOOK
T1 - Physical Work Demands and Fitness
T2 - Effects on Risk Factors for Cardiovascular Disease from a Randomized Controlled Trial among Cleaners
AU - Larsen, Mette Korshøj
N1 - CURIS 2015 NEXS 376
Den trykte afhandling er på 85 s. + 4 papers (167 s.)
PY - 2015
Y1 - 2015
N2 - Cardiovascular disease is the most frequent cause of death, accounting for more than 30 % of all
annual deaths. Elevated incidence of cardiovascular disease is seen among occupational groups
exposed to high occupational physical activity, like cleaners. Conversely, moderate to high leisure time physical activity reduces risk factors for cardiovascular disease. However, it is not known whether this also holds for workers exposed to high occupational physical activity, or whether it will lead to a cardiovascular overload. The study therefore investigated whether an aerobic exercise worksite intervention among cleaners would improve or impair risk factors for
cardiovascular disease.
This study was a 4-month cluster-randomized aerobic exercise worksite intervention. The
intervention was developed in close collaboration with the participants, and accounted for the
context of the specific worksites. The effects were evaluated with objective physiological or
diurnal data in an intention-to-treat analysis using multi-adjusted mixed models. The results
indicated that the intervention led to several improvements in risk factors for cardiovascular
disease, e.g. enhanced cardiorespiratory fitness, reduced resting and sleeping heart rate, relative
aerobic workload and level of high sensitive C-reactive protein. However, the intervention also
elevated resting and 24-hour ambulatory blood pressure.
Secondary analysis, stratified on high vs low (≥/< 30 % VO2max) relative aerobic workloads,
showed that cleaners exposed to high relative aerobic workloads obtained more pronounced
increases of resting and 24-hour ambulatory blood pressure, an unaltered cardiorespiratory fitness and a reduced sleeping heart rate. The enhanced resting and 24-hour ambulatory blood pressure may be explained as a potential cardiovascular overload. However, the inflammatory biomarker of high sensitive C-reactive protein decreased in the aerobic exercise group compared to the reference group, not supporting the idea of a potential cardiovascular overload.
Further studies are needed to understand the mechanisms behind the cardiovascular effects seen from high occupational physical activity, and to make evidence-based recommendations for the prevention of cardiovascular disease among workers exposed to high occupational physical activity and high relative aerobic workloads. Moreover, these results points to the relevance of targeting reductions in the relative aerobic workload, because of the improvement in cardiovascular health, especially among those participants exposed to low relative aerobic
workloads, in this aerobic exercise worksite intervention. Thus, multifaceted interventions might
be more successful in reducing the risk of cardiovascular disease among workers with high
occupational physical activity, e.g. by a combination of aerobic exercise and ergonomic
interventions or organizational changes.
AB - Cardiovascular disease is the most frequent cause of death, accounting for more than 30 % of all
annual deaths. Elevated incidence of cardiovascular disease is seen among occupational groups
exposed to high occupational physical activity, like cleaners. Conversely, moderate to high leisure time physical activity reduces risk factors for cardiovascular disease. However, it is not known whether this also holds for workers exposed to high occupational physical activity, or whether it will lead to a cardiovascular overload. The study therefore investigated whether an aerobic exercise worksite intervention among cleaners would improve or impair risk factors for
cardiovascular disease.
This study was a 4-month cluster-randomized aerobic exercise worksite intervention. The
intervention was developed in close collaboration with the participants, and accounted for the
context of the specific worksites. The effects were evaluated with objective physiological or
diurnal data in an intention-to-treat analysis using multi-adjusted mixed models. The results
indicated that the intervention led to several improvements in risk factors for cardiovascular
disease, e.g. enhanced cardiorespiratory fitness, reduced resting and sleeping heart rate, relative
aerobic workload and level of high sensitive C-reactive protein. However, the intervention also
elevated resting and 24-hour ambulatory blood pressure.
Secondary analysis, stratified on high vs low (≥/< 30 % VO2max) relative aerobic workloads,
showed that cleaners exposed to high relative aerobic workloads obtained more pronounced
increases of resting and 24-hour ambulatory blood pressure, an unaltered cardiorespiratory fitness and a reduced sleeping heart rate. The enhanced resting and 24-hour ambulatory blood pressure may be explained as a potential cardiovascular overload. However, the inflammatory biomarker of high sensitive C-reactive protein decreased in the aerobic exercise group compared to the reference group, not supporting the idea of a potential cardiovascular overload.
Further studies are needed to understand the mechanisms behind the cardiovascular effects seen from high occupational physical activity, and to make evidence-based recommendations for the prevention of cardiovascular disease among workers exposed to high occupational physical activity and high relative aerobic workloads. Moreover, these results points to the relevance of targeting reductions in the relative aerobic workload, because of the improvement in cardiovascular health, especially among those participants exposed to low relative aerobic
workloads, in this aerobic exercise worksite intervention. Thus, multifaceted interventions might
be more successful in reducing the risk of cardiovascular disease among workers with high
occupational physical activity, e.g. by a combination of aerobic exercise and ergonomic
interventions or organizational changes.
UR - https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01009154661&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK
M3 - Ph.D. thesis
BT - Physical Work Demands and Fitness
PB - Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen
CY - Copenhagen
ER -
