Regular exercise during pregnancy is beneficial, but athletes often exceed the recommended 150 min of moderate-intensity activity, incorporate high-intensity exercises. The upper limit for exercise intensity and duration on fetal and maternal safety remains uncertain. A concern is a maternal core body temperature of >39.0 °C, potentially increase the risk of heat-related fetal malformations and complications during pregnancy. Blood flow redirection for thermoregulation could compromise fetal cardiovascular function, increasing the risk of miscarriage and preterm labor. This study evaluated whether pregnant women (gestational weeks 25–35) were at risk of exceeding a core body temperature of 39.0 °C during high-intensity running. We also investigated effects on skin temperature, fluid loss, and thermal sensation, comparing pregnant athletes to non-pregnant controls.
In this comparative cross-sectional study, 30 elite and recreational athletes (pregnant n = 15) completed up to five high-intensity treadmill-intervals. Core and skin temperature were continuously measured. Body weight was utilized to calculate the amount of fluid loss.
Highest core body temperature were 38.76 °C and 39.56 °C in one pregnant and non-pregnant participant, respectively. Pregnant participants had lower core body temperatures (mean difference −0.47 °C, p ≤ 0.001) initially and a smaller increase (0.10 °C, p ≤ 0.003) during later intervals compared with the non-pregnant controls. Pregnant participants also showed a greater increase in skin temperature (4.08 ± 0.72 °C vs. 3.25 ± 0.86 °C, p = 0.008) and fluid loss (0.81 ± 0.19 L vs. 0.50 ± 0.12 L, p˂0.001).
Physiological changes in pregnancy may enhance thermoregulation, indicating that high-intensity interval runs are unlikely to pose a risk of exceeding a core body temperature of 39 °C for pregnant athletes.
Physical activity (PA) self-efficacy plays a crucial role in maintaining and enhancing PA behaviors in children. However, the effectiveness of eHealth interventions in boosting PA self-efficacy among children remains uncertain. Furthermore, which behavior change techniques (BCTs) used in eHealth interventions can positively influence children's PA self-efficacy needs further exploration for designing tailored eHealth interventions. Therefore, this systematic review and meta-analysis aimed to identify the effectiveness of eHealth interventions and BCTs in promoting children's PA self-efficacy.
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted across six databases (PubMed, Web of Science, EBSCOhost, Ovid, SPORTDiscus, PsycINFO) up to January 8, 2024. Inclusion criteria included randomized controlled trials (RCT), quasi-experimental, and two-group experiments that examined the effect of eHealth interventions on PA self-efficacy among healthy children aged 0–18 years. The Physiotherapy Evidence Database (PEDro) scale was utilized to assess the risk of bias. Random effects meta-analysis was performed to determine the effectiveness of eHealth interventions and BCTs in selected studies.
Sixteen studies were screened, including 6020 participants with an average age of 11.58 years (SD = 2.87). The result showed small but significant intervention effects with high heterogeneity (I2 = 92.34 %) for postintervention PA self-efficacy (Hedges’ g = 0.315; 95 % CI = 0.069, 0.562, p = .012). Two BCTs were significantly associated with enhanced PA self-efficacy: instruction on performing the behavior (p = .003) and behavior demonstration (p = .036). Additionally, studies that adopted social support (unspecified) a nd prompt/cues were significantly less effective than studies that did not use these BCTs (p = .001).
The findings showed that eHealth interventions positively affect children's PA self-efficacy. This review is the pioneer in focusing on BCTs in eHealth interventions for children. The insights gained provide valuable knowledge about tailored BCTs incorporated into eHealth interventions that promote children's PA self-efficacy.
International Prospective Register of Systematic Review (PROSPERO): CRD42024512058.