Seasonal variations in fitness levels are anticipated to correspond with the phases of the competitive season. Such cycles in fitness characteristics have been described for soccer (Thomas and Reilly, 1979) and Rugby Union (Tong and Mayes, 1995) players. In Gaelic football the major competition, the All-Ireland inter-county championship, takes place in the summer, starting in May and culminating in the All-Ireland final in September. The intercounty League programme is held over the winter and spring months. The aim of the research was to monitor fitness and performance measures in elite Gaelic footballers over a complete season.