Effort perception
As the Borg rating of perceived exertion scale was not appropriate for children, investigators set about developing child-specific scales which employed numbers, words and/or images that were more familiar and understandable. Numerous studies have examined the validity and reliability of such scales as the CERT, PCERT and OMNI amongst children aged 5 to 16 years, across different modes of exercise (cycling, running, stepping, resistance exercise), protocols (intermittent vs. continuous, incremental vs. non-incremental) and paradigms (estimation vs. production). Such laboratory-based research has enabled the general conclusion that children can, especially with practise, use effort perception scales to differentiate between exercise intensity levels, and to self-regulate their exercise output to match various levels indicated by them. However, inconsistencies in the methodological approaches adopted diminish the certainty of some of the interpretations made by researchers. The scope for research in the application of effort perception in physical education and activity/health promotion is considerable.