Short bursts of activity have big impact on child health, study shows
Frequent, short bursts of activity are as good for children's health as longer exercise sessions, new UK research suggests. The findings, published in the International Journal of Pediatric Obesity, imply that children should be encouraged to engage in frequent, short periods of activity. The good news is that this is how children tend to behave naturally. Most physical activity guidelines recommend that children engage in at least 60 minutes of moderate to vigorous activity per day. However, while some say that this activity should be accumulated in sessions of 5 to 10 minutes, others say that it is OK if it is built up in brief spells of activity lasting under 5 minutes. In fact, studies suggest that children aged between 6 and 10 rarely remain active for more than 5 to 10 minutes, and that the average duration of activity bouts is actually around 20 seconds. The aim of this latest study was to examine the impact on children's health of the frequency, intensity and duration of activity bouts. To do this, the scientists attached electronic devices called accelerometers to 47 boys aged 8 to 10. Most of the boys were in good health and within a healthy weight range. The youngsters wore the device for seven days; during that time, it provided the researchers with second-by-second information on the activity levels of the wearers. The scientists also measured the boys' waist circumference, aerobic fitness and microvascular function (an early indicator of cardiovascular risk). The study revealed that the relationship between the frequency of short bursts (i.e. lasting less than four seconds) of activity and health was as strong as the relationship between longer bouts (i.e. over five minutes) and health. 'Our study suggests that physical activity is associated with health, irrespective of whether it is accumulated in short bursts or long bouts,' explained lead researcher Michelle Stone of the University of Exeter. 'Previous research has shown that children are more naturally inclined to engage in short bursts of running, jumping and playing with a ball, and do not tend to sustain bouts of exercise lasting five or more minutes. This is especially true for activities that are more vigorous in nature. 'If future research backs up our findings, we would do better to encourage young children to do what they do naturally, rather than trying to enforce long exercise sessions on them,' she continued. 'This could be a useful way of improving enjoyment and sustainability of healthy physical activity levels in childhood.' 'Whilst it is not possible to attribute cause and effect relationships from this study, this is the first time that such short bursts of naturally occurring habitual activity behaviour in young children have been associated with microvascular function,' added Roger Eston, also of the University of Exeter. 'The findings from this study enrich our understanding of the potential links between naturally occurring sporadic physical activity and health in our children.' The researchers call for further research into the impacts of sporadic exercise on health in the longer term; this should help to determine whether differences in the activity patterns of children are a cause or a consequence of good health. They also suggest a comparison between boys and girls. The results of such studies could be used to influence guidelines on childhood activity levels, and so ensure that children are encouraged to be active in a way that has the greatest impact on their health.
Countries
United Kingdom