Substitution patterns in women’s Division I college soccer: Game strategy or fatigue prevention

This chapter examines the relationship between a commonly used measure of training intensity, using GPS, and the response of the biomarker sCort in players during the first half of an EPL season. Salivary cortisol (sCort) is a catabolic hormone that has relevance to sports scientists attempting to characterise responses to training load and matches in football and other team sports. It has been demonstrated that the physical demands of English Premier League (EPL) soccer have become more intense over the last seven seasons. Although some work has examined the impact of training intensity upon acute immune and physiological response in soccer training and match play, there is no published work assessing the chronic impact of training load upon biomarker response in EPL soccer. Samples on other days of the training week were excluded from this particular analysis. The High Metabolic Load (HML) data included in this chapter is calculated based upon that work rather than directly measured by the devices.