“…increasing training loads; (Gustafsson, Kenttä, & Hassmén, 2011;Mellalieu, Neil, Hanton, & Fletcher, 2009). Furthermore, becoming a successful elite athlete is virtually impossible without performing close to one's performance limit during training and competition over extended periods of time (Kellmann, Kölling, & Pelka, 2017;Lemyre, Roberts, & Stray-Gundersen, 2007;Meeusen et al, 2013). While many young athletes are willing to do so (Lemyre, et al, 2007), prolonged exposure to high training loads and other sources of stress may have negative consequences (Meeusen, et al, 2013), and ultimately lead to overtraining syndrome (Kenttä & Hassmen, 2002), overuse injuries (Oyen, Klungland Torstveit, & Sundgot-Borgen, 2009), and/or burnout symptoms (Cresswell & Eklund, 2006).…”