Sleep patterns amongst Chinese children

Physical Activity Practice, Sleeping Habits and Academic Achievement

“…Sleep is an active, repetitive and reversible state that promotes the development of physical, cognitive, affective and behavioral aspects. Sleep is necessary to maintain all the brain functions affecting the good state of human memory, learning/memory capacity, the brain's optimal function or the neurobehavioral function [78][79][80][81]. Therefore, sleep habits are one of the most important daily routines that must be correctly done [82].…”

“…During the school and college stages, the students cope with sleep problems, such as sleep deprivation or sleep restriction, which produces a poor sleep quality and then academic problems [73]. The specific literature refers to a mean of 9 hours per night of sleep as a good requirement; however, 45% of the students sleep less than 8 hours per night and around 20-50% considers that they have sleepiness during the day [77,78,80]. The reasons of this time sleep reduction can be an interaction of intrinsic (e.g., physical and physiological changes induced by the puberty) or extrinsic (e.g., school schedules, extracurricular activities, family lifestyle, etc.)…”

“…The available studies have showed this negative relationship between sleep and academic performance in primary and secondary schools [78] as well as at the university level [76]. The authors referred that the sleepiness produced by the poor quality of sleep impairs the above-mentioned, learning, cognitive and neurobehavioral function [65,68].…”

“…According to the scientific research [69,70], some aspects may modify the sleep schedules in both the intrinsic and extrinsic factors. On the one hand, the intrinsic factors can be affected by the students' level of stress due to academic pressure [65,72,78] or close schedules [69,75] that induce to a high-pressure level of tension, anxiety and feelings of stress that disrupt or modify the circadian rhythms [65,81]. On the other hand, the extrinsic factors can be associated to the high number of hours after the school doing extracurricular activities [72,73]; the social factors that modify the schedules such as the adolescent life, the campus life or love relationships [74,76]; the use of afternoon naps [75]; the importance of time watching TV, internet or playing videogames [78]; the influence of the sleep debts during the course (e.g., more fatigue during the second semester) [75] or the weekday or weekend day routines (i.e., the weekend may make up the sleep lost accumulated during the week, but dramatic changes can occur in the sleep-wake cycle if the students increase dramatically the number of hours of sleep) [77].…”

“…The mechanism associated to the lack of sleep is the level of hormones regulating the body appetite due to a decrease of leptin secretion and an increase of the ghrelin [92]. This mechanism creates an imbalance of both hormones increasing the feelings of hungry and the need to intake foods and then the incidence of overweight and obesity, coronary heart disease, type 2 diabetes or hypertension [73,78,92]. Additionally, this relationship appears to have another influence on obese/overweight student's physical growth, the reduction in height [73,78,92].…”