RESUMEN

OBJECTIVES: This study investigates the impact of different work paces on cardiorespiratory outcomes, perceived effort and carried load (CL) in industrial workers. METHODS: A randomised cross-over trial was conducted at a mid-sized steel company. We included 12 healthy industrial workers (8 females, age: mean 44±SD 9 years, height: 1.70±0.08 m, body mass: 79.5±13.4 kg) with at least 6 months of working experience. All participants performed 5 min of piece work at 100% (P100), 115% (P115) and 130% (P130) of the company's internal target yielded in a randomised order, separated by 5 min familiarisation breaks. The primary outcome was energy expenditure (EE), calculated from a respiratory gas exchange using a metabolic analyser. Secondary outcomes were total ventilation, oxygen uptake, carbon dioxide release, respiratory exchange ratio, heart rate and rating of perceived effort (0-10). Furthermore, the metabolic equivalent and the CL were calculated. Data were analysed with repeated measure analyses of variance. RESULTS: For EE, a large 'pace' effect with a small difference between P100 and P130 (165.9±33.4 vs 178.8±40.1 kcal/hour-1, p=0.008, standard mean difference, SMD=0.35) was revealed. Additionally, a large difference in CL between all paces (p<0.001, SMD≥1.10) was revealed. No adverse events occurred. CONCLUSIONS: Cardiorespiratory outcomes rise with increased work pace, but the practical relevance of these differences still needs to be specified. However, the CL will add up over time and may impact musculoskeletal health in the long term.