g. [10, 11]]. During this protocol, measures of power (W) and force (N) were measured using a force plate (AccuPower, Athletic Republic, Fargo, ND, USA). Blood variables Blood samples were collected via an indwelling catheter placed in the antecubital forearm vein at the beginning of each day of exercise testing. Samples were obtained before exercise testing began, immediately following vertical jump, following squat testing, immediately post all exercise testing, and fifteen minutes following cessation of exercise, for a total of five blood
timepoints. After whole blood analyses, blood plasma was obtained via centrifugation (Hettich Centrifuge, Beverly, MA) at 3200 RPM, 4°C, 20 minutes, and stored at -80°C until further analysis. Betaine was analyzed in EDTA preserved plasma samples. 17-AAG High performance liquid chromatography was utilized with a silica column in a mixed partition and ion exchange mode following
a method previously described [12]. Hematocrit (International Equipment Co., Needham Heights, MA, microcapillary reader) and hemoglobin concentration (Hemocue 201+ Analyzer, Lake Forest, CA) were obtained from whole blood, plasma osmolality was measured with an osmometer (Advanced Instruments, Inc., Norwood, MA, Model 3250) prior to sample storage. Glucose and lactate concentrations were analyzed using a glucose/lactate analyzer (2300 YSI Stat Plus, Yellow Springs, OH). All ACP-196 datasheet blood
variables were measured in respective SI units. Other variables Subjects submitted self-administered 3-day diet records and six week activity records to verify consistency in diet and activity during study participation. Urine specific gravity (USG) (ATAGO clinical refractometer, Cole-Parmer, Vernon Hills, IL), osmolality, and 5 FU body mass were measured prior to each exercise testing session to verify hydration status. Statistical MS-275 molecular weight analysis All variables were analyzed using Repeated Measures ANOVA with supplement treatment (placebo or betaine, two levels) and the appropriate number of time points as within subject factors. The sphericity assumption was met and significance was set at p < 0.05. Post hoc comparisons were t tests with Bonferroni corrections applied. The main effects of supplement were evaluated in the statistical model, and time effect and supplement × time interaction effects were also evaluated. Data are presented as means ± standard deviation for all variables. Results Subjects reported that they could not distinguish which treatment (P or B) they received in either of the two phases of supplementation. All subjects reported similar physical activity and diet prior to each exercise test and throughout study participation.