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1.
Eur J Appl Physiol ; 113(3): 793-802, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22976217

RESUMEN

Our aim was to examine the effect of betaine supplementation on selected circulating hormonal measures and Akt muscle signaling proteins after an acute exercise session. Twelve trained men (age 19.7 ± 1.23 years) underwent 2 weeks of supplementation with either betaine (B) (1.25 g BID) or placebo (P). Following a 2-week washout period, subjects underwent supplementation with the other treatment (B or P). Before and after each 2-week period, subjects performed an acute exercise session (AES). Circulating GH, IGF-1, cortisol, and insulin were measured. Vastus lateralis samples were analyzed for signaling proteins (Akt, p70 S6k, AMPK). B (vs. P) supplementation approached a significant increase in GH (mean ± SD (Area under the curve, AUC), B: 40.72 ± 6.14, P: 38.28 ± 5.54, p = 0.060) and significantly increased IGF-1 (mean ± SD (AUC), B: 106.19 ± 13.45, P: 95.10 ± 14.23, p = 0.010), but significantly decreased cortisol (mean ± SD (AUC), B: 1,079.18 ± 110.02, P: 1,228.53 ± 130.32, p = 0.007). There was no difference in insulin (AUC). B increased resting Total muscle Akt (p = 0.003). B potentiated phosphorylation (relative to P) of Akt (Ser(473)) and p70 S6 k (Thr(389)) (p = 0.016 and p = 0.005, respectively). Phosphorylation of AMPK (Thr(172)) decreased during both treatments (both p = 0.001). Betaine (vs. placebo) supplementation enhanced both the anabolic endocrine profile and the corresponding anabolic signaling environment, suggesting increased protein synthesis.


Asunto(s)
Betaína/administración & dosificación , Suplementos Dietéticos , Sistema Endocrino/efectos de los fármacos , Ejercicio Físico/fisiología , Fármacos Gastrointestinales/administración & dosificación , Metabolismo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Adolescente , Adulto , Estudios Cruzados , Método Doble Ciego , Sistema Endocrino/metabolismo , Humanos , Masculino , Esfuerzo Físico/efectos de los fármacos , Esfuerzo Físico/fisiología , Placebos , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Adulto Joven
2.
Curr Sports Med Rep ; 10(4): 191-6, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23531893

RESUMEN

During a urine drug testing program, an athlete may make a claim that the results of a positive test have arisen from factors that were out of his or her control, and therefore, he or she should not be held responsible for the results. Some of these claims may include classic claims of passive inhalation of marijuana smoke or ingestion of poppy seeds leading to positive tests. In addition, with the proliferation of nutritional supplements on the market, many athletes claim that they accidentally ingested a banned substance contained in one of these. It is important that any sports medicine physician involved with sports drug testing be informed of the data that either support or refute these claims and that he or she contribute to a program wherein adequate education and policy establishment help to limit the likelihood of such claims. This article will review the data to help address these claims.


Asunto(s)
Atletas , Doping en los Deportes , Detección de Abuso de Sustancias , Orina/química , Cannabis , Suplementos Dietéticos , Reacciones Falso Positivas , Contaminación de Alimentos , Hormonas/orina , Humanos , Contaminación por Humo de Tabaco
3.
Med Sci Sports Exerc ; 41(5): 1111-21, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19346975

RESUMEN

INTRODUCTION: Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. PURPOSE: The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armor (MA); Abbott Laboratories, Abbott Park, IL) containing beta-hydroxy-beta-methylbutyrate (HMB) on hormonal and muscle damage markers in response to 12 wk of resistance exercise. METHODS: Seventeen healthy men (mean body mass: 77.9 +/- 7.2 kg; mean height: 174.3 +/- 12.4 cm; mean age: 22.9 +/- 3.8 yr) were matched and randomized into two groups and performed 12 wk of periodized heavy resistance training while supplementing with either MA or an isocaloric, isonitrogenous placebo (CON). Every 2 wk during the 12-wk intervention, resting blood draws were obtained, and muscle strength and power were measured. In addition, blood draws were obtained before, during, and after a standardized resistance exercise challenge performed pre-, mid-, and posttraining. RESULTS: Lean body mass, muscle strength, and muscle power significantly (P

Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Aminoácidos/metabolismo , Suplementos Dietéticos , Entrenamiento de Fuerza , Adulto , Aminoácidos/administración & dosificación , Método Doble Ciego , Humanos , Masculino , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/fisiología , Adulto Joven
4.
Eur J Appl Physiol ; 105(5): 665-72, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19048277

RESUMEN

The influence of a proprietary blend of modified cellulose and cetylated fatty acids (Trisynextrade mark, Imagenetix, Inc., San Diego, CA 92127, USA) on adipocytokine and regional body composition responses to a weight loss program was examined. Twenty-two women (Supplement group (S) (n = 11): age = 36.8 +/- 7.2 years; weight = 87.1 +/- 6.2 kg; % body fat = 43.4 +/- 4.1; Placebo group (P) (n = 11): age = 38.3 +/- 6.8 years; weight = 86.9 +/- 4.7 kg; % body fat = 44.3 +/- 2.0) completed an 8-week placebo-controlled, double-blind study consisting of a caloric restricted diet and cardiovascular exercise. Body composition and serum insulin, leptin, and adiponectin were assessed at pre-, mid-, and post-intervention. From pre- to post-intervention, significant decreases (P < 0.05) were observed for body weight (S: 87.1 +/- 6.2-77.9 +/- 5.1 kg; P: 86.9 +/- 4.7-82.7 +/- 3.8 kg) (P < 0.05 S vs. P), % body fat (S: 43.4 +/- 4.1-36.1 +/- 3.6; P: 44.3 +/- 2.0-40.6 +/- 1.2) (P < 0.05 S vs. P), leptin (S: 28.3 +/- 3.5-16.2 +/- 2.6 ng ml(-1); P: 29.4 +/- 3.2-19.9 +/- 1.1 ng ml(-1)) (P < 0.05 S vs. P), and insulin (S: 7.3 +/- 0.8-5.1 +/- 0.2 mU l(-1); P: 7.7 +/- 0.9-5.1 +/- 0.3 mU l(-1)). Serum adiponectin increased (P < 0.05) (S: 12.2 +/- 2.4-26.3 +/- 3.0 microg ml(-1): 12.6 +/- 2.0-21.8 +/- 3.1 microg ml(-1)) (P < 0.05 for S vs. P). Supplementation with a proprietary blend of modified cellulose and cetylated fatty acids during an 8-week weight loss program exhibited favorable effects on adipocytokines and regional body composition.


Asunto(s)
Adipoquinas/sangre , Adiposidad/fisiología , Celulosa/uso terapéutico , Suplementos Dietéticos , Terapia por Ejercicio , Ácidos Grasos/uso terapéutico , Sobrepeso/terapia , Adulto , Composición Corporal/fisiología , Terapia Combinada , Método Doble Ciego , Femenino , Humanos , Obesidad/terapia , Sobrepeso/sangre , Sobrepeso/dietoterapia
5.
Am J Cardiol ; 102(10): 1413-7, 2008 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-18993165

RESUMEN

Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.


Asunto(s)
Vasos Sanguíneos/inmunología , Carnitina/administración & dosificación , Grasas de la Dieta , Suplementos Dietéticos , Alimentos , Interleucina-6/sangre , Vasodilatación , Adulto , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Adulto Joven
6.
Eur J Appl Physiol ; 101(5): 637-46, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17701421

RESUMEN

The purpose of this study was to determine the influence of a comprehensive multi-component nutritional supplement on performance, hormonal, and metabolic responses to an acute bout of resistance exercise. Nine healthy subjects ingested either Muscle Fuel (MF) or a matched placebo (PL) for 7 days. Subjects then reported to the laboratory, ingested the corresponding supplement, and performed two consecutive days of heavy resistance exercise testing with associated blood draws. MF supplementation improved vertical jump (VJ) power output and the number of repetitions performed at 80% of one repetition maximum (1RM). Additionally, MF supplementation potentiated growth hormone (GH), testosterone, and insulin-like growth factor-1 responses to exercise. Concentrations of circulating myoglobin and creatine kinase (CK) were attenuated immediately following resistance exercise during the MF trial, indicating that MF partially mediated some form of exercise-induced muscle tissue damage. In summary MF enhanced performance and hormonal responses associated with an acute bout of resistance exercise. These responses indicate that MF supplementation augments the quality of an acute bout of resistance exercise thereby increasing the endocrine signaling and recovery following heavy resistance exercise.


Asunto(s)
Suplementos Dietéticos , Ejercicio Físico/fisiología , Hormonas/sangre , Adulto , Aminoácidos/sangre , Biomarcadores/sangre , Glucemia/metabolismo , Composición Corporal/fisiología , Creatina Quinasa/metabolismo , Estudios Cruzados , Dieta , Método Doble Ciego , Frecuencia Cardíaca/fisiología , Hormona de Crecimiento Humana/sangre , Humanos , Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Ácido Láctico/sangre , Masculino , Actividad Motora/fisiología , Fatiga Muscular/fisiología , Fuerza Muscular/fisiología , Mioglobina/metabolismo , Testosterona/sangre
7.
J Strength Cond Res ; 21(1): 259-64, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17313301

RESUMEN

L-carnitine L-tartrate (LCLT) supplementation beneficially affects markers of postexercise metabolic stress and muscle damage. However, to date, no study has determined the dose response of LCLT to elicit such responses. Therefore, the purpose of this study was to determine the effects of different doses of LCLT on criterion variables previously shown to be responsive to LCLT supplementation. Eight healthy men (22 +/- 3 y, 174 +/- 5 cm, 83.0 +/- 15.3 kg) were supplemented with 0 g, 1 g, and 2 g of LCLT for 3 weeks and then performed a bout of resistance exercise (5 sets of 15-20 repetition maximum with a 2-min rest between sets) with associated blood draws. This procedure was performed in a balanced, randomized, repeated measures design. Serum carnitine concentrations increased (p < or = 0.05) following the 1 g and 2 g doses, with the 2-g dose providing the highest carnitine concentrations. The 1- and 2-g doses reduced postexercise serum hypoxanthine, serum xanthine oxidase, serum myoglobin, and perceived muscle soreness. In conclusion, both the 1- and 2-g doses were effective in mediating various markers of metabolic stress and of muscle soreness. Use of LCLT appears to attenuate metabolic stress and the hypoxic chain of events leading to muscle damage after exercise.


Asunto(s)
Biomarcadores/sangre , Carnitina/farmacología , Suplementos Dietéticos , Tartratos/farmacología , Adulto , Análisis de Varianza , Área Bajo la Curva , Glucemia/análisis , Carnitina/sangre , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Prueba de Esfuerzo , Fuerza de la Mano , Humanos , Hipoxantina/sangre , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Lactatos/sangre , Masculino , Mioglobina/sangre , Dolor/fisiopatología , Educación y Entrenamiento Físico , Tartratos/sangre , Xantina Oxidasa/sangre
9.
J Rheumatol ; 31(4): 767-74, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15088305

RESUMEN

OBJECTIVE: To examine the effect of a topical cream consisting of cetylated fatty acids on functional performance in patients diagnosed with osteoarthritis (OA) of one or both knees. METHODS: Forty patients diagnosed with knee OA were randomly assigned to one of 2 topical treatment groups: (1) cetylated fatty acid (CFA) (n = 20; age 62.7 +/- 11.7 yrs); or (2) placebo group (n = 20; age 64.6 +/- 10.5 yrs). Patients were tested on 3 occasions: (1) baseline (T1), (2) 30 min after initial treatment (T2), and (3) after 30-day treatment of cream application twice per day (T3). Assessments included knee range of motion (ROM), timed "up-and-go" from a chair and stair climbing, medial step-down test, and the unilateral anterior reach. RESULTS: For stair climbing ability and the up-and-go test, significant decreases in time were observed at T2 and T3 compared to T1 in the CFA group only. These differences were significant between groups. Supine ROM of the knees increased at T2 and T3 in CFA group, whereas no difference was observed in the placebo group. For the medial step-down test, significant improvement was observed at T2 and T3 compared to T1 in CFA group. For the unilateral anterior reach, significant improvement was observed for both legs in CFA group and in only the left leg in the placebo group. However, the improvements observed in CFA group were significantly greater than placebo group for both legs. CONCLUSION: Use of a CFA topical cream is an effective treatment for improving knee ROM, ability to ascend/descend stairs, ability to rise from sitting, walk and sit down, and unilateral balance.


Asunto(s)
Osteoartritis de la Rodilla/fisiopatología , Osteoartritis de la Rodilla/rehabilitación , Calidad de Vida , Ceras/uso terapéutico , Actividades Cotidianas , Administración Tópica , Método Doble Ciego , Emolientes , Prueba de Esfuerzo , Humanos , Persona de Mediana Edad , Rango del Movimiento Articular/efectos de los fármacos , Recuperación de la Función/efectos de los fármacos , Resultado del Tratamiento
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