• fitness testing
• children
• physical activity
• health

Tomkinson et al 1 report temporal trends in aerobic fitness of 1 142 026 children aged 7–19 years old using estimates from the 20 m shuttle run. The data show continued declines in fitness described as ‘indicative of declines in population health’. The authors propose that surveillance of children’s fitness should be undertaken within ‘harmonised national health surveys’. The authors’ convictions in the potential value of extending paediatric health surveillance to include fitness measures will be shared by readers who recognise the utility of fitness testing performed routinely for diagnostic screening and athlete monitoring.2

Aerobic fitness is a stronger predictor of mortality than established cardiovascular disease risk factors.3 Medicine acknowledges the diagnostic utility of exercise tests, but their tendency to ‘focus on the ischemic ST-segment’3 may explain why aerobic fitness is so rarely reported as an outcome in the medical literature (figure 1). The American Heart Association’s call for a US national fitness registry4 echoed recently the authors’5 proposal for a repository of children’s shuttle-run data to ‘enable temporal tracking and improve health surveillance’.