The association between physical activity and sleep during pregnancy: a systematic review

The 24-h activity cycle and cardiovascular outcomes: establishing biological plausibility using arterial stiffness as an intermediate outcome

This review proposes a biologically plausible working model for the relationship between the 24-h activity cycle (24-HAC) and cardiovascular disease. The 24-HAC encompasses moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior (SB), and sleep. MVPA confers the greatest relative cardioprotective effect, when considering MVPA represents just 2% of the day if physical activity guidelines (30 min/day) are met. While we have well-established guidelines for MVPA, those for the remaining activity behaviors are vague. The vague guidelines are attributable to our limited mechanistic understanding of the independent and additive effects of these behaviors on the cardiovascular system. Our proposed biological model places arterial stiffness, a measure of vascular aging, as the key intermediate outcome. Starting with prolonged exposure to SB or static standing, we propose that the reported transient increases in arterial stiffness are driven by a cascade of negative hemodynamic effects following venous pooling. The subsequent autonomic, metabolic, and hormonal changes further impair vascular function. Vascular dysfunction can be offset by using mechanistic-informed interruption strategies and by engaging in protective behaviors throughout the day. Physical activity, especially MVPA, can confer protection by chronically improving endothelial function and associated protective mechanisms. Conversely, poor sleep, especially in duration and quality, negatively affects hormonal, metabolic, autonomic, and hemodynamic variables that can confound the physiological responses to next-day activity behaviors. Our hope is that the proposed biologically plausible working model will assist in furthering our understanding of the effects of these complex, interrelated activity behaviors on the cardiovascular system.

Effects of Two Physical Activity Interventions on Sleep and Sedentary Time in Pregnant Women

Pregnancy is often associated with poor sleep and high sedentary time (SED). We investigated the effect of physical activity (PA) interventions on sleep and SED in pregnant women. A secondary analysis of a randomized controlled trial (n = 219) explored the effect of structured supervised exercise training (EXE) or motivational counseling on PA (MOT) compared to standard prenatal care (CON) on sleep and SED during pregnancy. Three times during pregnancy, sleep was determined by the Pittsburgh Sleep Quality Index (PSQI) and SED by the Pregnancy Physical Activity Questionnaire (PPAQ). Also, a wrist-worn consumer activity tracker measured sleep and SED continuously. Data from the activity tracker confirmed that sleep time decreases, and SED increases by approx. 30 and 24 min/day, respectively, from baseline (maximum gestational age (GA) week 15) to delivery. Compared to CON, the global PSQI score was better for EXE in GA week 28 (-0.8 [-1.5; -0.1], p = 0.031) and for both EXE and MOT in GA week 34 (-1 [-2; -0.5], p = 0.002; -1 [-2; -0.1], p = 0.026). In GA week 28, SED (h/day) from PPAQ was lower in EXE compared to both CON and MOT (-0.69 [-1; -0.0], p = 0.049; -0.6 [-1.0; -0.02], p = 0.042). In conclusion, PA interventions during pregnancy improved sleep quality and reduced SED.

Application of the COM-B Framework to Understand Facilitators and Barriers for Practising Physical Activity among Pregnant Women and Midwives Participating in the WELL-DONE! Study

Regular physical activity (PA) is protective and reduces disease burden but remains a challenge for pregnant women (PW). According to the World Health Organization (WHO) guidelines, PW without contraindications should practice 150 min of moderate PA per week. Nonetheless, PA levels are concerningly low among PW. The aim of this study was to investigate PW's and midwives' perceptions regarding PA and recommended guidelines, and use this information to inform future health promotion strategies. We recruited 10 PW and 10 midwives to participate in online focus groups conducted between July 2020 and April 2021. Focus group probes and data analysis were guided by the COM-B (capability, opportunity, motivation-behaviour) framework. The majority of the sample had already practised PA, recognized the importance of PA during pregnancy, and considered the WHO guidelines reasonable. Notwithstanding, PW wanted more specific instruction on PA and desired opportunities to practice. Additional barriers reported by PW included low self-efficacy and lack of motivation. Midwives considered the lack of specific knowledge and confidence in managing PA as the main obstacles. The current findings suggest that PW and midwives need specific training in PA to overcome both psychological and physical barriers. Midwives play a vital role in educating and encouraging PA among PW.