Association between health-related physical fitness indicators and working ability: a systematic review.

OBJECTIVES: Work ability (WA) reflects a balance between work demands and an individual's ability to meet them. It is influenced by several occupational and health-related factors including the individual's physical fitness (PF). Therefore, the aim of the present study was to provide an overview of the possible relationship between PF measures and the individual's WA. METHODS: A systematic review of studies published up to December 1, 2022 and available in PubMed, Scopus, and ISI Web of Science databases, was performed. Results have been summarized according to the specific PF parameter explored. RESULTS: The 14 reviewed studies, enrolling 47 to 1005 workers, all showed a satisfactory methodological quality. Some positive evidence emerged for a possible association between changes in aerobic capacity, walking speed, balance, flexibility, muscle strength, and WA perception. However, the limited number of studies, their cross-sectional design, the different PF performance indicators, populations, and job tasks explored prevented definite conclusions. CONCLUSIONS: Future longitudinal studies should be planned to confirm such positive results and identify PF indicators better predictive for changes in the WA of employees engaged in specific job tasks, particularly in physically demanding activities. This may be helpful to include PF performance tests in occupational health practice as an integrated part of risk assessment and management strategies as well as in health and well-being promotion plans.

The challenges of defining hormesis in epidemiological studies: The case of radiation hormesis.

In the current radiation protection system, preventive measures and occupational exposure limits for controlling occupational exposure to ionizing radiation are based on the linear no-threshold extrapolation model. However, currently an increasing body of evidence indicates that this paradigm predicts very poorly biological responses in the low-dose exposure region. In addition, several in vitro and in vivo studies demonstrated the presence of hormetic dose response curves correlated to ionizing radiation low exposure. In this regard, it is noteworthy that also the findings of different epidemiological studies, conducted in different categories of occupationally exposed workers (e.g., healthcare, nuclear industrial and aircrew workers), observed lower rates of mortality and/or morbidity from cancer and/or other diseases in exposed workers than in unexposed ones or in the general population, then suggesting the possible occurrence of hormesis. Nevertheless, these results should be considered with caution since the identification of hormetic response in epidemiological studies is rather challenging because of a number of major limitations. In this regard, some of the most remarkable shortcomings found in epidemiological studies performed in workers exposed to ionizing radiation are represented by lack or inadequate definition of exposure doses, use of surrogates of exposure, narrow dose ranges, lack of proper control groups and poor evaluation of confounding factors. Therefore, considering the valuable role and contribution that epidemiological studies might provide to the complex risk assessment and management process, there is a clear and urgent need to overcome the aforementioned limits in order to achieve an adequate, useful and more real-life risk assessment that should also include the key concept of hormesis. Thus, in the present conceptual article we also discuss and provide possible approaches to improve the capacity of epidemiological studies to identify/define the hormetic response and consequently improve the complex process of risk assessment of ionizing radiation at low exposure doses.