The effect of chronotype upon physical performance during Australian Rules football matches scheduled in the morning, afternoon and evening

Individual differences in circadian rhythm or diurnal variations are referred to as chronotypes. A chronotype is a behavioural phenotype that has the ability to reflect ones innate circadian rhythm. Chronotypes are often measured on a continuous scale of "morningness-eveningness". The current gold standard for evaluation of chronotype for general populations is the Horne-Östberg Morningness-Eveningness Questionnaire which categorises individuals as "evening types", "morning types" or "intermediate types". Each end of this scale is viewed as dichotomous in nature with evening types often being referred to as owls and morning types as larks. These categories reflect the time of day in which individuals are most mentally and physically proficient. Individuals with a high score on morningness perform both mentally and physically better within the morning hours whilst their evening orientated counterparts have difficulties in getting up in the morning and perform best in the late afternoon or evening hours.