251 research outputs found

    Effects of Exercise Training on Cardiovascular Risk and Anti-Risk Factors in Adolescent Boys

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    Adolescence is a critical period in the formation of cardiovascular risk factors. Long-term exercise training has been found to be reversely related to risk factors levels in adolescents. PURPOSE: To determine the effects of training (swimming and soccer) over a twelve week timeframe on some cardiovascular risk and anti-risk factors in adolescent boys. METHODS: Forty two boys, including swimmers (SW n=14), soccer players (SO n=13), and a control group (C n=15) (Age=11.8±1.38yrs; Ht=149±.8.38cm; Wt=40±7.8kg) volunteered for this study. Fasting blood samples were obtained prior to initiation of training, at weeks 4, 8, and 12. A 3×4 repeated measures ANOVA with LSD post hoc analysis was conducted to determine the difference between three groups in ApoA1, ApoB, Apo A1/ApoB, Apo B/Apo A1, and VLDL. RESULTS: Participants in training groups had greater changes in ApoA1 (p=0.01), ApoB (p=0.000), ApoA1/ApoB ratio (p=0.000), and ApoB/ApoA1 ratio (p=0.000). Significant changes were not observed in VLDL levels (p=0.65) across all three groups. CONCLUSION: Exercise training had a significant effect to change ApoA1, ApoB, ApoA1/ApoB, and ApoB/ApoA1 levels in adolescent athletes. Participation in regular training is recommended for adolescents to improve cardiovascular risk and anti-risk factor profiles. Significant effects of training on VLDL levels were inconclusive for 12-week training period

    Effects of eight weeks of an alleged aromatase inhibiting nutritional supplement 6-OXO (androst-4-ene-3,6,17-trione) on serum hormone profiles and clinical safety markers in resistance-trained, eugonadal males

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    The purpose of this study was to determine the effects of 6-OXO, a purported nutritional aromatase inhibitor, in a dose dependent manner on body composition, serum hormone levels, and clinical safety markers in resistance trained males. Sixteen males were supplemented with either 300 mg or 600 mg of 6-OXO in a double-blind manner for eight weeks. Blood and urine samples were obtained at weeks 0, 1, 3, 8, and 11 (after a 3-week washout period). Blood samples were analyzed for total testosterone (TT), free testosterone (FT), dihydrotestosterone (DHT), estradiol, estriol, estrone, SHBG, leutinizing hormone (LH), follicle stimulating hormone (FSH), growth hormone (GH), cortisol, FT/estradiol (T/E). Blood and urine were also analyzed for clinical chemistry markers. Data were analyzed with two-way MANOVA. For all of the serum hormones, there were no significant differences between groups (p > 0.05). Compared to baseline, free testosterone underwent overall increases of 90% for 300 mg 6-OXO and 84% for 600 mg, respectively (p < 0.05). DHT underwent significant overall increases (p < 0.05) of 192% and 265% with 300 mg and 600 mg, respectively. T/E increased 53% and 67% for 300 mg and 600 mg 6-OXO, respectively. For estrone, 300 mg produced an overall increase of 22%, whereas 600 mg caused a 52% increase (p < 0.05). Body composition did not change with supplementation (p > 0.05) and clinical safety markers were not adversely affected with ingestion of either supplement dose (p > 0.05). While neither of the 6-OXO dosages appears to have any negative effects on clinical chemistry markers, supplementation at a daily dosage of 300 mg and 600 mg for eight weeks did not completely inhibit aromatase activity, yet significantly increased FT, DHT, and T/E

    Peri-exercise co-ingestion of branched-chain amino acids and carbohydrate in men does not preferentially augment resistance exercise-induced increases in PI3K/Akt-mTOR pathway markers indicative of muscle protein synthesis

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    The effects of a single bout of resistance exercise (RE) in conjunction with peri-exercise branched chain amino acid (BCAA) and carbohydrate (CHO) ingestion on skeletal muscle signaling markers indicative of muscle protein synthesis (MPS) were determined. It was hypothesized that CHO + BCAA would elicit a more profound effect on these signaling markers compared to CHO. Twenty-seven males were randomly assigned to CHO, CHO + BCAA, or placebo (PLC) groups. Four sets of leg presses and leg extensions were performed at 80% 1RM. Supplements were ingested 30 min and immediately prior to and after RE. Venous blood and muscle biopsy samples were obtained immediately prior to supplement ingestion and 0.5 hr, 2 hr, and 6 hr after RE. Serum insulin and glucose and phosphorylated levels of muscle insulin receptor substrate 1 (IRS1), protein kinase B (Akt), mammalian target of rapamycin (mTOR), p70S6 kinase (p70S6K), and 4E binding protein 1 (4E-BP1) were assessed. Data were analyzed by two-way repeated measures ANOVA. Significant group x time interactions were observed for glucose and insulin (p \u3c 0.05) showing that CHO and CHO + BCAA were significantly greater than PLC. Significant time main effects were observed for IRS1 (p = 0.001), Akt (p = 0.031), mTOR (p = 0.003), and p70S6K (p = 0.001). CHO and CHO + BCAA supplementation significantly increased IRS-1 compared to PLC (p = 0.002). However, peri-exercise co-ingestion of CHO and BCAA did not augment RE-induced increases in skeletal muscle signaling markers indicative of MPS when compared to CHO

    ISSN Roundtable: FAQs About the ISSN

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    <p/> <p>Mission Statement of the ISSN</p> <p>The mission of the International Society of Sports Nutrition is to be recognized as the leading professional organization in the study and application of sports nutrition. The ISSN is dedicated to promoting and supporting the study, practice, education, research and development of sports nutrition and the sports nutrition profession. All information disseminated by the ISSN is unbiased and scientifically supported.</p

    The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels

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    Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. In a double-blind manner, participants were randomly assigned to a maltodextrose placebo (PLA), creatine monohydrate (CRT), or creatine ethyl ester (CEE) group. The supplements were orally ingested at a dose of 0.30 g/kg fat-free body mass (approximately 20 g/day) for five days followed by ingestion at 0.075 g/kg fat free mass (approximately 5 g/day) for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p = 0.041) compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition, body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion, when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most likely be attributed to the training protocol itself, rather than the supplementation regimen
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