Effect of betaine supplementation on cycling sprint performance

<p>Abstract</p> <p>Purpose</p> <p>To examine the effect of betaine supplementation on cycling sprint performance.</p> <p>Methods</p> <p>Sixteen recreationally active subjects (7 females and 9 males) completed three sprint tests, each consisting of four 12 sec efforts against a resistance equal to 5.5% of body weight; efforts were separated by 2.5 min of cycling at zero resistance. Test one established baseline; test two and three were preceded by seven days of daily consumption of 591 ml of a carbohydrate-electrolyte beverage as a placebo or a carbohydrate-electrolyte beverage containing 0.42% betaine (approximately 2.5 grams of betaine a day); half the beverage was consumed in the morning and the other half in the afternoon. We used a double blind random order cross-over design; there was a 3 wk washout between trials two and three. Average and maximum peak and mean power were analyzed with one-way repeated measures ANOVA and, where indicated, a Student Newman-Keuls.</p> <p>Results</p> <p>Compared to baseline, betaine ingestion increased average peak power (6.4%; p < 0.001), maximum peak power (5.7%; p < 0.001), average mean power (5.4%; p = 0.004), and maximum mean power (4.4%; p = 0.004) for all subjects combined. Compared to placebo, betaine ingestion significantly increased average peak power (3.4%; p = 0.026), maximum peak power max (3.8%; p = 0.007), average mean power (3.3%; p = 0.034), and maximum mean power (3.5%; p = 0.011) for all subjects combined. There were no differences between the placebo and baseline trials.</p> <p>Conclusions</p> <p>One week of betaine ingestion improved cycling sprint power in recreationally active males and females.</p

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Does Caffeine Increase Fat Metabolism?: A Systematic Review and Meta-Analysis

Whether caffeine (CAF) increases fat metabolism remains debatable. Using systematic review coupled with meta-analysis, our aim was to determine effects of CAF on fat metabolism and the relevant factors moderating this effect. Electronic databases PubMed, SPORTDiscus, and Web of Science were searched using the following string: CAF AND (fat OR lipid) AND (metabolism OR oxidation). A meta-analytic approach aggregated data from 94 studies examining CAF’s effect on fat metabolism assessed by different biomarkers. The overall effect size (ES) was 0.39 (95% confidence interval [CI] [0.30, 0.47], p \u3c .001), indicating a small effect of CAF to increase fat metabolism; however, ES was significantly higher (p \u3c .001) based on blood biomarkers (e.g., free fatty acids, glycerol) (ES = 0.55, 95% CI [0.43, 0.67]) versus expired gas analysis (respiratory exchange ratio, calculated fat oxidation) (ES = 0.26, 95% CI [0.16, 0.37]), although both were greater than zero. Fat metabolism increased to a greater extent (p = .02) during rest (ES = 0.51, 95% CI [0.41, 0.62]) versus exercise (ES = 0.35, 95% CI [0.26, 0.44]) across all studies, although ES was not different for studies reporting both conditions (ES = 0.49 and 0.44, respectively). There were no subgroup differences based on participants’ fitness level, sex, or CAF dosage. CAF ingestion increases fat metabolism but is more consistent with blood biomarkers versus whole-body gas exchange measures. CAF has a small effect during rest across all studies, although similar to exercise when compared within the same study. CAF dosage did not moderate this effect

The Gender Gap in Sport Performance: Equity Influences Equality

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)NatuurwetenskappeFisiologiese Wetenskapp

Effect of Race and Musculoskeletal Development on the Accuracy of Air Plethysmography

Purpose: The purpose of this study was to determine the effect of race and musculoskeletal development on the accuracy of estimates of body fatness (% fat) via air displacement plethysmography (AP). Methods: Estimates of % fat were made via AP, hydrostatic weighing (HW), dual-energy x-ray absorptiometry (DXA), and the criterion, a four-component model (4C) in 64 black (B) and white (W) men, who were either resistance trained (RT) or served as controls (C). Results: Based on a three-way ANOVA, there were no statistically significant three-way or race x musculoskeletal development interactions. There was no main effect of race on the validity of estimating % fat by AP; the mean bias between % FatAP and % Fat4C was similar for B (3.6 % body fat) and W (3.7 %). In addition, the density of the fat-free mass (Dffm) for B (1.098 +/- 0.002 g.mL-1) was not different than 1.10 g.mL-1. There was a significant effect of musculoskeletal development on the validity of the estimation of % fat from AP; the mean difference in % fat between % FatAP and % Fat4C was less in RT (1.5 % body fat) than in C (5.3 %), but a large SEE of 5.5 % was observed for RT. A significant (P \u3c 0.05) correlation was found between the mean bias between methods and body volume (-0.44) and mesomorphy (-0.55). Conclusions: Race does not affect the accuracy of estimating %f at by AP. Race-specific equations estimating % fat via densitometry (e.g., AP, HW) such as the Schutte are not justified, because Dffm is not greater than 1.10 g.mL-1. Estimation of % fat via AP is more accurate in larger individuals with high musculoskeletal development as a group, but individual results are highly variable