Football match-play and training sessions, both technical and physical, apply particular stresses to the physiological systems. These stresses can vary depending on the intensity of work, environmental conditions, level of ability and physical maturity of the players. Physiological responses to the game and the accompanying training sessions have been well documented in comprehensive studies of adult elite and sub-elite players (Bangsbo, 1993; Reilly, 1994). Methods of analysis have used metabolic responses such as blood lactate and hormonal changes, and movement studies by means of video recordings and motional analysis. Analyses of the concentrations of blood borne or intramuscular metabolites are invasive in nature and can be difficult to administer whereas assessment using video equipment can be expensive and time consuming.