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accepted (> 1.8 g nutritional supplementation often go by the `more is better' philosophy, causing many athletes to make uneducated decisions regarding their supplementation habits intakes of collegiate strength/power athletes were stratified into three separate categories of daily protein consumption; below recommended levels (1.0 1.4 g composition and endocrine changes during a 12-week resistance training program. METHODS Subjects: Following an explanation of all procedures, risks and benefits each subject gave his informed consent to participate in this study. The Institutional Review Board of the College approved the research protocol. Subjects were not permitted to use any anabolic agents known to increase performance such as creatine, testosterone precursors, growth hormone or anabolic steroids for the six months prior to the onset of the study. Protein supplementation was considered to be acceptable for inclusion in this study to enable an increase in protein consumption. supplementation was accomplished via a health questionnaire filled out during subject recruitment. All subjects were experienced resistance trained athletes from the college's football team or sprinters or throwers from the college's track and field team with at least 2 years of resistance training experience. All subjects performed the same resistance training program for 12 weeks. The training program was a 4-day per week, split routine (see Table 1) that was supervised by research personnel. All subjects completed a daily training log and turned it in at the end of each week. In addition, all subjects completed a 3-day dietary recall every week. Based upon the average weekly protein intakes determined for the 12-week study the subjects were categorized into three groups; below recommended daily protein intake (BL; 1.0 1.4 g recommended daily protein intake (AL; > 2.0 g Dietary Recall. Dietary intake was continuously monitored throughout the study using 3-day dietary records every week. Subjects were instructed to record as accurately as possible everything they consumed during the day including between meal and late evening snacks. Testing Protocol. Subjects reported to the Human Performance Laboratory on two separate occasions. The first testing session occurred prior to the onset of the training program (PRE) and the second testing session occurred at the conclusion of the 12-week training program (POST). All testing sessions occurred at the same time of day. Blood Measurements. Subjects were required to arrive at the laboratory in the early morning following an overnight fast for blood draws. All blood draws occurred at the same time of day for each testing session. Each blood sample was obtained from an antecubital arm vein using a 20- gauge disposable needle equipped with a Vacutainer position. Blood samples were collected into a Vacutainer temperature and subsequently centrifuged at 1500 x g for 15 minutes. The resulting serum was placed into separate 1.8-ml microcentrifuge tubes and frozen at - 80 Biochemical and Hormonal Analyses. Serum total testosterone, growth hormone, IGF-I, and cortisol concentrations were determined using enzyme immunoassays (EIA) and enzyme-linked immunosorbent assays (ELISA) (Diagnostic Systems Laboratories, Webster, TX). Determinations of serum immunoreactivity values were made using a SpectraMax340 Spectrophotometer (Molecular Devices, Sunnyvale, CA). To eliminate inter-assay variance, all samples for a particular assay were thawed once and analyzed in the same assay run. All samples were run in duplicate with a mean intra- assay variance of < 10%. The molar ratio of total testosterone to cortisol (T/C ratio) was determined for each testing session. |
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Study 