Details

Autor(en) / Beteiligte

• Le Roux, Elisa
• De Jong, Nathan P.
• Blanc, Stéphane
• Simon, Chantal
• Bessesen, Daniel H.
• Bergouignan, Audrey

Titel

Physiology of physical inactivity, sedentary behaviours and non‐exercise activity: insights from the space bedrest model

Ist Teil von

• The Journal of physiology, 2022-03, Vol.600 (5), p.1037-1051

Ort / Verlag

England: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Quelle

Wiley HSS Collection

Beschreibungen/Notizen

• Physical inactivity, i.e. not reaching the recommended level of physical activity (PA), and sedentary behaviours (SB), i.e. sitting time, have been associated with increased risk for common metabolic diseases. Recent epidemiological data suggest that high volumes of SB are detrimental to metabolic health, even in the presence of regular exercise, i.e. moderate/vigorous PA. This suggests that the health effects of SB are independent from those of exercise. However, experimentally testing this hypothesis is complicated because of the difficulty in disassociating SB from PA. Bedrest studies, a traditional space science model, can offer new insights. In some bedrest studies, an exercise training protocol has been used to counteract the harmful effects of inactivity. While bedrest induces an inactive and sedentary state, exercise with bedrest represents a unique model of sedentary yet physically active people. Here, we review bedrest studies with and without exercise training. Although exercise training prevents the loss of muscle mass and function, even large volumes of exercise are not sufficient to fully counteract the negative metabolic adaptations triggered by inactivity. This observation supports the existence of independent adverse health effects of SB, but also the potential benefits of non‐exercise activity, i.e. daily living light PA. We gathered available data to examine the complex relationships between exercise, non‐exercise activity, SB and health outcomes. Given the large amount of SB in modern societies, the sole promotion of exercise, i.e. moderate/vigorous PA may be insufficient, and promotion of light PA may be a complimentary approach to improve health. figure legend Although the exact physiological mechanisms remain unclear, sedentariness has been shown to negatively affect metabolic health and the main organs involved in its regulation. The 2020 World Health Organization (Bull et al. 2020) guidelines on physical activity recommend practicing a weekly volume of 150–300 min of moderate intensity or 75–150 min of vigorous intensity or an equivalent combination of moderate/vigorous physical activity (MVPA) to limit the appearance of certain maladaptations. Recently, some large‐scale studies have revealed the importance of light physical activity (LPA) to prevent the effects of sedentary lifestyles. Since then, limiting periods of sedentary time have become part of the recommendations for the first time, raising the question of how to reduce periods of sedentary living. This review aims to highlight the potential role of LPA in effectively reducing sitting time and preventing its associated harmful health effects. Intervention studies specifically targeting LPA and sedentary behaviour, in addition to MVPA, are necessary to develop specific recommendations and limit the risk of developing metabolic diseases.