Heavy Physical Work: Cardiovascular Load in Male Construction Workers.

Lars-Kristian Lunde,Morten Wærsted,Stein Knardahl,Kaj Veiersted,Gunn-Helen Moen,Markus Koch

doi:10.3390/ijerph13040356

Abstract

This study aimed to elucidate cardiovascular loads (CVL) in construction workers during work and leisure by relative heart rate (RHR) over several days. Furthermore, we sought to evaluate the level of CVL in relation to individual factors, work ability, musculoskeletal pain and subjective general health. From a group of 255 construction workers responding to the baseline questionnaire, the CVL during work and leisure time was determined by recording RHR in 42 workers over 3–4 days. Almost 60% of the workday was spent below 20% RHR. The mean RHR during work for all participants was 16% RHR, with large differences between professions. On average, the 42 workers spent 14% of the workday at a RHR above 33%, and four subjects (10%) had a mean RHR above 33% during work. Eight (19%) of the participants had a mean length of their workday exceeding calculated maximal acceptable work time. Seven persons (17%) experienced on average one or more episode(s) of 5 min or more continuously above 33% RHR. The cardiovascular load at work was significantly associated with age and O2max, but not with work ability, musculoskeletal pain or subjective general health.

Highlights

Physical demands at work are considered an important risk factor of several musculoskeletal disorders (MSD; see [1] for a systematic review)
We further evaluated the level of cardiovascular load in relation to individual factors, work ability, MSDs and general health
For the group as a whole an average workday was characterized by most time spent in ranges below 20% relative heart rate (RHR) and less time in higher ranges

Summary

Introduction

Physical demands at work are considered an important risk factor of several musculoskeletal disorders (MSD; see [1] for a systematic review). Heavy physical work may be associated with level of work ability [2]. Heavy physical work is a general term, encompassing both working at high levels of aerobic load relative to maximum oxygen uptake, handling of heavy objects, and performing tasks demanding sustained exertion at high levels of force. The term heavy physical work does not specify pathogenic factors to target for workplace interventions to prevent health problems. Individual performance and production output depend on being able to sustain workload over a period of time, which depends on both individual capacity and type of tasks performed. Åstrand and coworkers have pointed out that the physical workload should be determined with indirect calorimetry and that the oxygen uptake must be evaluated with regard to the capacity of the working muscles [5]. Others have described workload limits for physically demanding jobs through

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