Nearly 60% of American children do not have healthy cardiorespiratory fitness (CRF), according to new research published in Circulation.

CRF is the body’s ability to supply oxygen to muscles during physical activity and is a key indicator of overall health. Children with healthy CRF are more likely to live longer and be healthier adults, according to a press release. On the other hand, children with poor CRF are at a higher risk for type 2 diabetes, high blood pressure, and premature death from heart disease and stroke as adults. Children with obesity are more likely to have poor CRF, according to the press release. 

Studies conducted prior to the coronavirus disease 2019 pandemic show that children are spending more time on electronic devices, both recreationally and educationally. According to the press release, this means that physical activities are being replaced with sedentary activities. Prior studies have shown that increased sedentary time correlated with lower levels of CRF in children, but not among teens, according to the authors of the current study. 

Repeated bursts of vigorous physical activity, such as regular sprint running sessions between periods of rest, can improve CRF. Additionally, sports such as basketball, swimming, and tennis should be encouraged; however, social determinants of health, such as socioeconomic status and neighborhood characteristics, can lead to challenges in improving CRF, according to the study.  

A cardiopulmonary exercise test, conducted on a treadmill or cycle ergometer, is the most accurate measure of CRF in children, the researchers said. Several different tests exist and can be adapted and administered in a variety of environments. 

"Our hope is that this statement will also inspire research into finding valid, lower-cost alternative options for traditional cardiopulmonary exercise testing to assess CRF in all children, and improved CRF tests that can be done in an office with limited space and without the need for formally trained exercise physiology personnel…In the meantime, requiring physical activity for every grade level through high school would be a step in the right direction,” Geetha Raghuveer, MD, chair of the writing committee for the new scientific statement, a cardiologist at Children's Mercy Hospital and Professor of Pediatrics at the University of Missouri, said in the press release. 


Field tests are more reliable then patient surveys as they are not self-reported, according to the press release. However, many physician’s offices do not have the time, space, or personnel to administer the test. Researchers said this can be solved with bilateral communication between parents, physicians’ offices, and schools. 

Reference:  
Nearly 60% of American children lack healthy cardiorespiratory fitness (Press Release), Kansas City, MI, July 20, 2020, ScienceDaily, July 21, 2020