Active Voice: How Many Daily Step Counts Do Kids Need?
How Many Daily Step Counts Do Kids Need?
Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.
Rachel C. Colley is a Junior Research Scientist with the Healthy Active Living and Obesity Research Group at the Children’s Hospital of Eastern Ontario Research Institute in Ottawa, Canada. Her research focus includes the objective measurement of physical activity and the promotion of healthy lifestyles in overweight children and youth. See the May 2012 issue of Medicine & Science in Sports & Exercise® (MSSE) for a related methodological insight, titled “Daily Step Target to Measure Adherence to Physical Activity Guidelines in Children.”
It is well recognized that physical inactivity is a global public health problem and this reality has led to increased interest in its surveillance. New physical activity guidelines for children state that they should accumulate at least 60 minutes of moderate-to-vigorous physical activity every day (World Health Organization, U.S. Department of Health & Human Services, and the Canadian Society for Exercise Physiology). Measurement of progress towards this target is needed at the population level to provide researchers, practitioners and policy-makers with the necessary information to assess the success or failure of strategies put in place to tackle the childhood inactivity crisis.
Until quite recently, public health surveillance has relied on self-report tools to obtain information about physical activity – an approach that is limited because of recall and social desirability biases combined with a focus on leisure-time physical activity. National health surveys are now using accelerometers to objectively measure physical activity. These tools are advantageous, as they are not hampered by any bias or recall and they capture total daily movement (e.g., sedentary behavior through to vigorous physical activity) as well as daily step counts.
The cost and complexity of accelerometers make their use by the general population unrealistic. A good alternative, however, is to use a pedometer to track physical activity levels. Pedometers are accessible, both in cost and interpretability, to the general population and not just fitness professionals or researchers. Individuals can use pedometers to get an objective picture of their physical activity level and may assist those wanting to track progress towards meeting the current physical activity guidelines. A common question is: “How many steps do I need?” A goal of 10,000 step counts per day has long been recognized as an appropriate target for adults. An evidence-based target that equates to current physical activity guidelines has historically not been available for children and youth.
A range of daily step count values have been proposed for children and youth; however, none were meant to equate to the guidelines per se. Previous research has shown that “typical” children accumulate between 11,000 and 13,000 steps per day. Step counts that differentiate healthy weight from overweight or obese children tend to hover around 12,000 steps per day for girls and 15,000 steps per day for boys.
In a recent methodological insight published in MSSE, we examined the step count value that equates to 60 minutes of moderate-to-vigorous physical activity in a large sample of Canadian children and youth. We ran the analyses separately by age and gender but in the end, the differences in target values were negligible. Thus, we proposed that a single target could be recommended: 12,000 steps per day.
Despite considerable effort and resources, attenuating the childhood obesity crisis remains an elusive goal in North America. Many experts are starting to shift focus toward prevention efforts and part of this is promoting healthy levels of physical activity at the population level. The new step count target proposed is a step in the right direction in helping both individuals and health professionals to track physical activity.