Cardiovascular Responses to Exercise in Children

Abstract

The cardiovascular system of children responds to exercise differently than does that of an adult, although the mechanisms behind the differences are unclear. During dynamic exercise, it has been reported that heart rate (HR) response to the initiation of exercise is both faster and slower in children than adults. Furthermore, HR recovery has been reported to be faster in children. During submaximal steady state exercise, HR and total peripheral resistance are higher, while stroke volume [SV (ml)] and cardiac output [Q (L/min)] are lower in children at a given rate of work. At maximal exercise intensities HR is higher while SV and Q are lower in children than adults. Differences in cardiovascular responses to dynamic exercise between young boys and girls have also been reported. The majority of studies report that HR is lower and SV is higher in boys than girls at a given rate of work, although data to the contrary have been reported. These differences seem to be related to larger hearts in the boys. Further, the majority of the studies report that Q is similar in young boys and girls at a given rate of work. Few studies have reported differences between boys and girls at maximal intensities of exercise, and the results of those studies are inconsistent. Less is known about cardiovascular responses of children to static exercise compared with adults. A number of studies have reported that HR response to handgrip exercise is greater in children than adults, while others have reported no difference in this response. Even fewer studies have compared boys and girls in their cardiovascular response to static exercise and the results of these studies are also inconsistent. During prolonged exercise both children and adults exhibit cardiovascular drift (gradual increase in HR and decrease in SV). The direction and degree to which these changes differ between children and adults is unclear, with both greater and lesser responses being reported in children. Few studies have investigated differences in cardiovascular response to prolonged exercise between boys and girls. Those that have, report no difference between young boys and girls.

The effects of six weeks of training on physical fitness and performance in teenage and mature top-level soccer players

“…However, the magnitude of change is superior in mature players (18.3 vs. 7.8%) as compared to their younger counterparts. Several authors confirmed diminished level of physiological aerobic trainability in young athletes [2,22]. With a period of endurance training, increases in VO 2max in young athletes are generally no more than one third of those expected in adults [12].…”

The future of activity-promoting video games in clinical practice: Is it the ultimate exercise test in prepubertal children?

“…During submaximal steady state exercise, heart rate and total peripheral resistance are higher, while stroke volume and cardiac output are lower in children at a given rate of work. At maximal exercise intensities heart rate is higher while stroke volume and cardiac output are lower in children than in adults (12)(13)(14).…”

Respostas cardiopulmonares durante o esforço em crianças e adolescentes nascidas prematuras

“…A frequência cardíaca (FC) é um importante fator para a manutenção do DC e sabe-se que na criança em repouso, quando comparada ao adulto, a FC é maior, decrescendo com o aumento da idade (34) . Essa maior atividade cronotrópica deve-se a um mecanismo compensatório relacionado ao menor volume do coração, menor volume sanguíneo e, consequentemente, menor volume de ejeção (4) .…”

“…Em crianças nascidas a termo de diferentes faixas etárias, a FC máxima atingida durante o exercício é sempre acima dos 180 batimentos por minuto, sendo comuns valores de 200 batimentos por minuto no pico máximo (34,35) . Fisiologicamente, o aumento da intensidade do esforço e da demanda metabólica aumentam progressivamente e proporcionalmente à FC, tanto em adultos quanto em crianças.…”