[Effects of light therapy on sleep efficiency in older adults in long-term care facilities: a systematic review and meta-analysis].

Physical activity (PA) refers to any bodily movement produced by skeletal muscle contraction that results in energy expenditure and is essential for health maintenance (). Regular PA during pregnancy benefits both the mother and the fetus (). It can significantly reduce the risk of gestational hypertension, gestational diabetes mellitus, excessive weight gain, perinatal depression, low back pain, emergency cesarean section, and neonatal complications (; ; ), and also improves muscle strength, labor pain, postpartum weight recovery, and fetal oxygen supply (). PA is a modifiable factor for maternal and fetal health (). The recognition of PA as a vital sign has reshaped prenatal care (). The World Health Organization (WHO) recommends at least 150 min of moderate-intensity PA per week for pregnant women without contraindications or complications (). A survey conducted in Shanghai showed that 47.5% of pregnant women experienced physical inactivity, and only 2.8% met the recommended duration (). This low adherence may be partly because walking, a light-intensity activity, was the predominant form of PA, and some pregnant women and healthcare workers remain anxious about the risks of moderate-to-vigorous PA. Another study found that the prevalence of physical inactivity was highest (66.2%) in the first trimester (). The percentages of pregnant women in Jordan, Alabama and Rhode Island (USA), and Zimbabwe who met the WHO recommendations were 28.9, 8.8, and 11%, respectively (; ; ). Barriers to PA are defined as obstacles that hinder individuals from initiating, maintaining, or increasing PA (). Barriers to PA include intrapersonal barriers (e.g., fatigue, nausea, lack of motivation, and pain), interpersonal barriers (e.g., advice from others and unclear guidance), and environmental factors (e.g., weather conditions; ; ; ; ). BPAPS, developed by , assesses these domains. Mean BPAPS scores were 88.55 in Iran and 85.35 in Ibadan (; ). Pre-pregnancy body mass index, antenatal admission, education, parity, exercise attitudes, ethnicity, income, and pre-pregnancy exercise habits were associated with PA barriers (; ; ; ).