Reducing sedentary behaviour and physical inactivity in the workplace: protocol for a review of systematic reviews

Impact of Breaking up of Sitting Time on Anti-inflammatory Response Induced by Extracellular Vesicles

Physical inactivity and sedentary behaviors (SB) have promoted a dramatic increase in the incidence of a host of chronic disorders over the last century. The breaking up of sitting time (i.e., sitting to standing up transition) has been proposed as a promising solution in several epidemiological and clinical studies. In parallel to the large interest it initially created, there is a growing body of evidence indicating that breaking up prolonged sedentary time (i.e., > 7 h in sitting time) could reduce overall mortality risks by normalizing the inflammatory profile and cardiometabolic functions. Recent advances suggest that the latter health benefits, may be mediated through the immunomodulatory properties of extracellular vesicles. Primarily composed of miRNA, lipids, mRNA and proteins, these vesicles would influence metabolism and immune system functions by promoting M1 to M2 macrophage polarization (i.e., from a pro-inflammatory to anti-inflammatory phenotype) and improving endothelial function. The outcomes of interrupting prolonged sitting time may be attributed to molecular mechanisms induced by circulating angiogenic cells. Functionally, circulating angiogenic cells contribute to repair and remodel the vasculature. This effect is proposed to be mediated through the secretion of paracrine factors. The present review article intends to clarify the beneficial contributions of breaking up sitting time on extracellular vesicles formation and macrophage polarization (M1 and M2 phenotypes). Hence, it will highlight key mechanistic information regarding how breaking up sitting time protocols improves endothelial health by promoting antioxidant and anti-inflammatory responses in human organs and tissues.

Effects of combined training on metabolic profile, lung function, stress and quality of life in sedentary adults: A study protocol for a randomized controlled trial

Background

Both physical inactivity and sedentary behavior are considered modifiable risk factors for chronic diseases and all-cause mortality. Adult office-workers spend most of their working day in sedentary behaviors, so they are particularly at high risk of developed chronic diseases (e.g., cardiovascular diseases, metabolic disorders like diabetes mellitus, …). It seems important to promote behavioral changes that could prevent or delay metabolic disease development. Evidence supports the use of exercise programs, however, to date there are several knowledge gaps and inconsistencies in the literature regarding the effects of Combined Training (i.e., aerobic plus resistance training) in sedentary healthy adults. This paper outlines an RCT designed to evaluate the effects of a 16-week combined training program on biochemical and immune markers of metabolic disease, lung function, salivary stress hormones and subjective quality of life (primary outcomes), as well as on body composition and physical fitness (secondary outcomes) in sedentary middle-aged office-workers. Furthermore, we aimed to assess the associations between the changes promoted by the exercise program and the different variables studied.

Methods and design

This is a single-blinded two-arm RCT with parallel groups. A minimum of healthy 40 office-workers aged 40–64 years will be recruited to engage in a 16-week intervention study. After baseline assessments, participants will be randomized to one of the two groups: (1) combined training group or (2) control group. Baseline assessments will be repeated after 8 weeks of intervention (mid-testing) and upon completion of the intervention (post-testing).

Discussion

This RCT involves a multi-disciplinary approach and seems to be a relevant contribution to understanding the potential role of combined training in improving the metabolic profile, lung function, stress, and quality of life in adults. The results can provide important insights for clinical recommendations and for the optimization of strategies to prevent metabolic disorders in adults with sedentary jobs.

Trial registration

This trial is registered with ClinicalTrials.gov (registration number: NCT04868240; date of registration April 30, 2021).