A minimum of 12 participants were recruited for the present study, in order to detect potential between-treatment differences of 1.2-1.6 SD units with a β > 0.80. This sample size was estimated using calculations from Lipsey [29], and utilized effect-sizes reported in previous studies comparing the effects of CHO+Pro and CHO beverages on the dependent measures utilized
in this study (i.e. [7, 9, 10]). For example, using mean values reported by Valentine et al. [10], CHO+Pro ingestion produced an effect on post-exercise plasma CK values of approximately 1.6 SD units, assuming a correlation of 0.80 between repeated measurements [29]. 7-Cl-O-Nec1 molecular weight Training Protocols All testing was conducted during the athletes’ off-season training period. On two occasions, subjects performed one week of normal ‘baseline’ training, followed immediately by four days of increased training duration (ITD). Baseline training levels represented typical training types/amounts conducted by the team during off-season
training. The ITD period was Depsipeptide in vivo intended to increase total training duration by >25% during four consecutive days of training. The number of days of ITD (and daily training times) were selected to produce a practically-relevant increase in training demands, without Selleck Afatinib violating NCAA regulations limiting Division I athletes outside of the playing season to a maximum of 8 hr of athletically-related activities per week (NCAA Playing and Practice Limitations, Bylaw 17.1.5.2). Daily training sessions (Mon-Fri) consisted of alternating days of a) soccer-specific training drills and aerobic development activities, and b) strength and sprint training (Table 1). On Mon/Wed/Fri, the prescribed
training sessions consisted of a) warm-up (~10 min), b) agility drills (~10 min), c) main training session, and d) cool down (~10 min). The length of the main training segment on these days varied from 60-90 min (depending on whether it Oxalosuccinic acid occurred during baseline or ITD), and included soccer-specific training drills and game-play, with a heavy aerobic conditioning component. On Tu/Th the prescribed training consisted of a) warm-up (~10 min), b) main training session, and c) cool down (~10 min). The main training session on these days included sprint/plyometric training drills (such as ‘ladder footwork’, standardized agility runs and coordination drills), followed by resistance training exercises. The length of the main training segment varied from 55-70 min on these days (baseline or ITD). Sprint/plyometric exercises and resistance training comprised an equal portion of the main training session on these days. No organized training sessions were conducted for two days prior to the ITD periods (Sat/Sun). Athletes were permitted to exercise on their own, but were instructed to limit exercise to a maximum of 30-45 minutes of low-intensity aerobic exercise (jogging).