RESUMEN
PURPOSE: This study examined whether adding Dichrostachys glomerata (DG; 300 mg/d) to thermogenic supplements with (DG + C) and without (DG) caffeine and other nutrients affects weight loss, changes in body composition, and/or markers of health. METHODS: Sixty-eight participants (female, 54%) were grouped in a double-blind, parallel, stratified random, placebo-controlled manner to supplement their diet with a placebo, DG, or DG + C for 12 weeks while maintaining their normal diet and physical activity. Diet, physical activity, body weight, body composition, anthropometric measures, resting energy expenditure, fasting blood samples, and questionnaires were obtained at 0, 4, 8, and 12 weeks and analyzed using general linear models with repeated measures. Data are reported as mean (±SD) and change from baseline (mean, 95% confidence interval) for weeks 4, 8, and 12, respectively, with p values showing changes from baseline. RESULTS: DG treatment promoted significant but minor reductions in fat mass (-0.56 [-1.02, -0.14], p = 0.01; -0.63 [-1.23, -0.02], p = 0.04; -0.71 [-1.47, 0.09] kg, p = 0.08) and percent body fat (-0.46 [-0.96, -0.04], p = 0.07; -0.63 [-1.16, -0.10], p = 0.02; -0.78 [-1.45, 0.07] %, p = 0.03). There was some evidence that DG + C increased resting energy expenditure, decreased hunger, increased satiety, and improved sleep quality (diminished in DG + C). No other significant effects were observed. CONCLUSIONS: Ingestion of thermogenic supplements containing DG (300 mg/d) with and without caffeine and other nutrients in overweight but otherwise healthy participants who did not alter diet or physical activity promoted clinically insignificant changes in body weight and composition.
Asunto(s)
Enfermedades Cardiovasculares , Pérdida de Peso , Antropometría , Composición Corporal , Enfermedades Cardiovasculares/prevención & control , Suplementos Dietéticos , Método Doble Ciego , Femenino , Humanos , Masculino , TermogénesisRESUMEN
In a double-blind, crossover, randomized and placebo-controlled trial; 28 men and women ingested a placebo (PLA), 3 g of creatine nitrate (CNL), and 6 g of creatine nitrate (CNH) for 6 days. Participants repeated the experiment with the alternate supplements after a 7-day washout. Hemodynamic responses to a postural challenge, fasting blood samples, and bench press, leg press, and cycling time trial performance and recovery were assessed. Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM). No significant differences were found among treatments for hemodynamic responses, clinical blood markers or self-reported side effects. After 5 days of supplementation, one repetition maximum (1RM) bench press improved significantly for CNH (mean change, 95% CI; 6.1 [3.5, 8.7] kg) but not PLA (0.7 [-1.6, 3.0] kg or CNL (2.0 [-0.9, 4.9] kg, CNH, p = 0.01). CNH participants also tended to experience an attenuated loss in 1RM strength during the recovery performance tests following supplementation on day 5 (PLA: -9.3 [-13.5, -5.0], CNL: -9.3 [-13.5, -5.1], CNH: -3.9 [-6.6, -1.2] kg, p = 0.07). After 5 days, pre-supplementation 1RM leg press values increased significantly, only with CNH (24.7 [8.8, 40.6] kg, but not PLA (13.9 [-15.7, 43.5] or CNL (14.6 [-0.5, 29.7]). Further, post-supplementation 1RM leg press recovery did not decrease significantly for CNH (-13.3 [-31.9, 5.3], but did for PLA (-30.5 [-53.4, -7.7] and CNL (-29.0 [-49.5, -8.4]). CNL treatment promoted an increase in bench press repetitions at 70% of 1RM during recovery on day 5 (PLA: 0.4 [-0.8, 1.6], CNL: 0.9 [0.35, 1.5], CNH: 0.5 [-0.2, 0.3], p = 0.56), greater leg press endurance prior to supplementation on day 5 (PLA: -0.2 [-1.6, 1.2], CNL: 0.9 [0.2, 1.6], CNH: 0.2 [-0.5, 0.9], p = 0.25) and greater leg press endurance during recovery on day 5 (PLA: -0.03 [-1.2, 1.1], CNL: 1.1 [0.3, 1.9], CNH: 0.4 [-0.4, 1.2], p = 0.23). Cycling time trial performance (4 km) was not affected. Results indicate that creatine nitrate supplementation, up to a 6 g dose, for 6 days, appears to be safe and provide some ergogenic benefit.
Asunto(s)
Rendimiento Atlético , Creatina/administración & dosificación , Suplementos Dietéticos , Nitratos/administración & dosificación , Sustancias para Mejorar el Rendimiento/administración & dosificación , Adolescente , Adulto , Animales , Antropometría , Ciclismo , Composición Corporal , Creatina/sangre , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Hemodinámica , Humanos , Masculino , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Nitratos/sangre , Sustancias para Mejorar el Rendimiento/sangre , Resistencia Física , Encuestas y Cuestionarios , Resultado del Tratamiento , Adulto JovenRESUMEN
In a double-blind, randomized and crossover manner, 25 resistance-trained participants ingested a placebo (PLA) beverage containing 12 g of dextrose and a beverage (RTD) containing caffeine (200 mg), ß-alanine (2.1 g), arginine nitrate (1.3 g), niacin (65 mg), folic acid (325 mcg), and Vitamin B12 (45 mcg) for 7-days, separated by a 7-10-day. On day 1 and 6, participants donated a fasting blood sample and completed a side-effects questionnaire (SEQ), hemodynamic challenge test, 1-RM and muscular endurance tests (3 × 10 repetitions at 70% of 1-RM with the last set to failure on the bench press (BP) and leg press (LP)) followed by ingesting the assigned beverage. After 15 min, participants repeated the hemodynamic test, 1-RM tests, and performed a repetition to fatigue (RtF) test at 70% of 1-RM, followed by completing the SEQ. On day 2 and 7, participants donated a fasting blood sample, completed the SEQ, ingested the assigned beverage, rested 30 min, and performed a 4 km cycling time-trial (TT). Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM), adjusted for gender and relative caffeine intake. Data are presented as mean change (95% CI). An overall multivariate time × treatment interaction was observed on strength performance variables (p = 0.01). Acute RTD ingestion better maintained LP 1-RM (PLA: -0.285 (-0.49, -0.08); RTD: 0.23 (-0.50, 0.18) kg/kgFFM, p = 0.30); increased LP RtF (PLA: -2.60 (-6.8, 1.6); RTD: 4.00 (-0.2, 8.2) repetitions, p = 0.031); increased BP lifting volume (PLA: 0.001 (-0.13, 0.16); RTD: 0.03 (0.02, 0.04) kg/kgFFM, p = 0.007); and, increased total lifting volume (PLA: -13.12 (-36.9, 10.5); RTD: 21.06 (-2.7, 44.8) kg/kgFFM, p = 0.046). Short-term RTD ingestion maintained baseline LP 1-RM (PLA: -0.412 (-0.08, -0.07); RTD: 0.16 (-0.50, 0.18) kg/kgFFM, p = 0.30); LP RtF (PLA: 0.12 (-3.0, 3.2); RTD: 3.6 (0.5, 6.7) repetitions, p = 0.116); and, LP lifting volume (PLA: 3.64 (-8.8, 16.1); RTD: 16.25 (3.8, 28.7) kg/kgFFM, p = 0.157) to a greater degree than PLA. No significant differences were observed between treatments in cycling TT performance, hemodynamic assessment, fasting blood panels, or self-reported side effects.