Self-regulation plays a critical role in sport performance. An objective, psychophysiological marker of self-regulation is cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. The aim of this paper is to provide an overview of factors influencing cardiac vagal activity, which can be useful for athletes. Specifically, we organize this overview in two main domains: personal factors and environmental factors. Among the personal factors, we find the behavioural strategies that can be used by athletes: nutrition, non-ingestive oral habits, water immersion, body temperature reduction, sleeping habits, relaxation methods, cognitive techniques, praying, music, and exercise. Among environmental factors, we find those linked to the social (i.e., contact with humans and animals) and physical (i.e., aromas, lights, sounds, temperature, outdoor, altitude) environment. Future research directions are given, as well as practical implications for athletes and coaches.

Background Research suggests that physical activity (PA) enhances cognitive performance and prevents stress-related impairments of higher order cognitive functions like working memory (WM) performance. The aim of the current study was to investigate the effect of PA on WM performance after acute stress exposure in preadolescent children. Methods Regular PA was assessed for seven consecutive days during a typical school week using accelerometers in a sample of 44 preadolescent children (14 girls, M age = 11.29 years, SD age = 0.67). Following this period, participants performed an automated operational span (OSPAN) task immediately after being exposed to the Trier Social Stress Test for Children (TSST-C). Results Children exhibited prototypical response slopes in salivary cortisol and salivary α-amylase as markers of the endocrine and autonomic stress response immediately after psychosocial stress induction. A subsequent two-way ANOVA comparing high- and low-stress responders revealed a significant interaction between group affiliation and PA level on WM performance for both stress markers. Interestingly, best WM performance was demonstrated in children showing both high PA levels and high cortisol (or low α-amylase, respectively) stress responses. Conclusions Though patterns differed for salivary cortisol and salivary α-amylase, overall findings suggest that PA buffers the negative effects of stress on cognitive performance in children.