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1.
Med Sci Sports Exerc ; 55(5): 865-872, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36728325

RESUMEN

PURPOSE: American-style football (ASF) players are at increased risk for head injuries and cardiovascular disease. n-3 polyunsaturated fatty acids are cardioprotective, and emerging evidence suggests benefits for protection against head injuries. However, fundamental knowledge of n-3 polyunsaturated fatty acid dosing in athletes such as ASF players remains poorly understood. Therefore, this study investigated the dose-response effect of docosahexaenoic acid (DHA) supplementation in red blood cells (RBC) and as the Omega-3 Index (O3I), in collegiate ASF players throughout a competitive season. METHODS: Sixty-nine ASF players were randomly assigned placebo (corn oil), or 2, 4, or 6 g·d -1 of DHA supplement. Blood samples were collected at eight time points (T1-T8) over 27 wk. RBC were extracted and analyzed by gas-liquid chromatography. Compliant players who had samples collected at all time points were analyzed. A repeated-measures ANOVA was conducted to assess the dose-response effect of DHA over time, and between-group differences at individual time points were assessed by one-way ANOVA followed by Tukey post hoc test. RESULTS: A significant dose and time interaction was found, and all supplement groups had significantly greater DHA in RBC compared with placebo from T2-T8 ( P < 0.05). Athletes receiving 6 g·d -1 of DHA had the greatest O3I, relative to other groups, and the O3I reached steady state by 15 wk. The 6 g·d -1 group surpassed >8% on the O3I at approximately twice the rate of the 4 g·d -1 group (8 vs 15 wk). CONCLUSIONS: Our findings provide important fundamental knowledge demonstrating a dose-response incorporation of DHA into RBC membranes up to 6 g·d -1 . Furthermore, 6 g·d -1 of DHA can be used to rapidly achieve a desired O3I (>8%) in athletes in only 8 wk.


Asunto(s)
Traumatismos Craneocerebrales , Ácidos Grasos Omega-3 , Fútbol Americano , Humanos , Atletas , Suplementos Dietéticos , Ácidos Docosahexaenoicos/metabolismo , Ácido Eicosapentaenoico/metabolismo
2.
Nutrients ; 13(11)2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34836033

RESUMEN

BACKGROUND: EPA and DHA n-3 FA play crucial roles in both neurological and cardiovascular health and high dietary intakes along with supplementation suggest potential neuroprotection and concussion recovery support. Rugby athletes have a high risk of repetitive sub-concussive head impacts which may lead to long-term neurological deficits, but there is a lack of research looking into n-3 FA status in rugby players. We examined the dietary n-3 FA intake through a FFQ and n-3 FA status by measuring the percentage of n-3 FA and O3I in elite Canadian Rugby 7s players to show distribution across O3I risk zones; high risk, <4%; intermediate risk, 4 to 8%; and low risk, >8%. METHODS: n-3 FA profile and dietary intake as per FFQ were collected at the beginning of the 2017-2018 Rugby 7s season in male (n = 19; 24.84 ± 2.32 years; 95.23 ± 6.93 kg) and female (n = 15; 23.45 ± 3.10 years; 71.21 ± 5.79 kg) athletes. RESULTS: O3I averaged 4.54% ± 1.77, with female athlete scores slightly higher, and higher O3I scores in supplemented athletes (4.82% vs. 3.94%, p = 0.183), with a greater proportion of non-supplemented athletes in the high-risk category (45.5% vs. 39.1%). Dietary intake in non-supplemented athletes did not meet daily dietary recommendations for ALA or EPA + DHA compared to supplemented athletes. CONCLUSIONS: Overall, despite supplementation, O3I score remained in the high-risk category in a proportion of athletes who met recommended n-3 FA dietary intakes, and non-supplemented athletes had a higher proportion of O3I scores in the high-risk category, suggesting that dietary intake alone may not be enough and athletes may require additional dietary and n-3 FA supplementation to reduce neurological and cardiovascular risk.


Asunto(s)
Atletas/estadística & datos numéricos , Dieta/estadística & datos numéricos , Suplementos Dietéticos , Ácidos Grasos Omega-3/análisis , Rugby , Canadá , Encuestas sobre Dietas , Ingestión de Alimentos , Femenino , Humanos , Masculino , Estado Nutricional , Ingesta Diaria Recomendada , Adulto Joven
3.
J Int Soc Sports Nutr ; 18(1): 65, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34579748

RESUMEN

BACKGROUND: American-style football (ASF) athletes are at risk for cardiovascular disease (CVD) and exhibit elevated levels of serum neurofilament light (Nf-L), a biomarker of axonal injury that is associated with repetitive head impact exposure over the course of a season of competition. Supplementation with the w-3 fatty acid (FA) docosahexaenoic acid (DHA) attenuates serum Nf-L elevations and improves aspects of CVD, such as the omega-3 index (O3I). However, the effect of combining the w-3 FA eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) with DHA on, specifically, serum Nf-L in ASF athletes is unknown. Therefore, this study assessed the effect of supplemental w-3 FA (EPA+DPA+DHA) on serum Nf-L, plasma w-3 FAs, the O3I, and surrogate markers of inflammation over the course of a season. METHODS: A multi-site, non-randomized design, utilizing two American football teams was employed. One team (n = 3 1) received supplementation with a highly bioavailablew-3 FA formulation (2000mg DHA, 560mg EPA, 320mg DPA, Mindset®, Struct Nutrition, Missoula, MT) during pre-season and throughout the regular season, while the second team served as the control (n = 35) and did not undergo supplementation. Blood was sampled at specific times throughout pre- and regular season coincident w ith changes in intensity, physical contact, and changes in the incidence and severity of head impacts. Group differences were determined via a mixed-model between-within subjects ANOVA. Effect sizes were calculated using Cohen's dfor all between-group differences. Significance was set a priori at p< .05. RESULTS: Compared to the control group, ASF athletes in the treatment group experienced large increases in plasma EPA (p < .001, d = 1.71) and DHA (p < .001, d = 2.10) which contributed to increases in the O3I (p < .001, d = 2.16) and the EPA:AA ratio (p = .001, d = 0.83) and a reduction in the w-6: w-3 ratio (p < .001, d = 1.80). w-3 FA supplementation attenuated elevations in Nf-L (p = .024). The control group experienced a significant increase in Nf-L compared to baseline at several measurement time points (T2, T3, and T4 [p range < .001 - .005, drange = 0.59-0.85]). CONCLUSIONS: These findings suggest a cardio- and neuroprotective effect of combined EPA+DPA+DHA w-3 FA supplementation in American-style football athletes. TRIAL REGISTRATION: This trial was registered with the ISRCTN registry ( ISRCTN90306741 ).


Asunto(s)
Traumatismos en Atletas/sangre , Traumatismos Craneocerebrales/sangre , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Fútbol Americano/lesiones , Atletas , Biomarcadores/sangre , Ácidos Docosahexaenoicos/sangre , Ácido Eicosapentaenoico/sangre , Ácidos Grasos Omega-3/sangre , Ácidos Grasos Insaturados/sangre , Humanos , Masculino
4.
Probiotics Antimicrob Proteins ; 12(4): 1330-1339, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32358640

RESUMEN

The fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant proteins. In contrast to animal proteins, most plant proteins, such as pea protein, are incomplete proteins. Pea protein is low in methionine and contains lower amounts of branched-chain amino acids (BCAAs), which play a crucial role in muscle health. We hypothesized that probiotic supplementation results in favorable changes in the gut microbiota, aiding the absorption of amino acids from plant proteins by the host. Fifteen physically active men (24.2 ± 5.0 years; 85.3 ± 12.9 kg; 178.0 ± 7.6 cm; 16.7 ± 5.8% body fat) co-ingested 20 g of pea protein with either AminoAlta™, a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) plus 5 billion CFU L. paracasei LPC-S01 (DSM 26760), SOFAR S.p.A., Italy) or a placebo for 2 weeks in a randomized, double-blind, crossover design, separated by a 4-week washout period. Blood samples were taken at baseline and at 30-, 60-, 120-, and 180-min post-ingestion and analyzed for amino acid content. Probiotic administration significantly increased methionine, histidine, valine, leucine, isoleucine, tyrosine, total BCAA, and total EAA maximum concentrations (Cmax) and AUC without significantly changing the time to reach maximum concentrations. Probiotic supplementation can be an important nutritional strategy to improve post-prandial changes in blood amino acids and to overcome compositional shortcomings of plant proteins. ClinicalTrials.gov Identifier: ISRCTN38903788.


Asunto(s)
Aminoácidos/sangre , Proteínas en la Dieta/sangre , Absorción Intestinal/efectos de los fármacos , Lacticaseibacillus paracasei/fisiología , Proteínas de Guisantes/sangre , Probióticos/administración & dosificación , Adulto , Área Bajo la Curva , Estudios Cruzados , Proteínas en la Dieta/administración & dosificación , Método Doble Ciego , Microbioma Gastrointestinal/fisiología , Humanos , Absorción Intestinal/fisiología , Masculino , Proteínas de Guisantes/administración & dosificación
5.
Appl Physiol Nutr Metab ; 45(8): 886-892, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32119565

RESUMEN

Sports-related concussions (SRC) are traumatic brain injuries induced as the result of a biomechanical force to the body that temporarily impair neurological functions. Not all traumatic impacts reach the threshold necessary to produce concussive symptoms; however, the culmination of these events is known as a subconcussive impact (SCI). Athletes who have been diagnosed with a SRC or those who accumulate multiple SCI have exhibited structural damage to the brain, impairments to learning and memory, and an increase in depressive symptoms. This area is rapidly evolving, and current clinical definitions of injury, diagnosis, and treatment of SRC and SCI are reviewed. In tandem, there is also growing research examining the role of nutrition in brain injuries, focusing primarily on n-3 polyunsaturated fatty acids (PUFA). The potential role of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in reducing inflammation and promoting recovery following brain injury are also reviewed. Overall, advancements in the evaluation of SRC and SCI coupled with n-3 PUFA supplementation show promise in the management of brain injuries, leading to better long-term health outcomes for athletes. Novelty SRC have garnered widespread attention due to the growing body of reported prevalence in youth and professional sports. Current definitions and protocol(s) for diagnosing SRC and SCI have improved, but still require further evaluation. n-3, EPA and DHA, reduce inflammation and promote recovery following brain injuries in experimental models.


Asunto(s)
Traumatismos en Atletas/diagnóstico , Traumatismos en Atletas/terapia , Conmoción Encefálica/diagnóstico , Conmoción Encefálica/terapia , Ácidos Docosahexaenoicos/uso terapéutico , Ácido Eicosapentaenoico/uso terapéutico , Atletas , Suplementos Dietéticos , Humanos , Incidencia
6.
J Athl Train ; 54(1): 7-11, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30645147

RESUMEN

CONTEXT: The essential omega-3 fatty acids (ω-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibit vital biological roles and are critical for cardiovascular and neurologic health. Compared with the general population, football athletes may be at an increased risk of cardiovascular disease. Further, those same athletes are also exposed to repetitive head impacts, which may lead to long-term neurologic deficits. Both diets high in ω-3 FAs and supplementation with ω-3 FAs have been reported to reduce the risk of cardiovascular disease, and early evidence suggests a potential neuroprotective effect of supplementation. OBJECTIVE: To determine the (1) erythrocyte content of DHA and EPA, as measured by the Omega-3 Index, expressed as a percentage of total fatty acids, in National Collegiate Athletic Association Division I football athletes and (2) distribution across the Omega-3 Index risk zones established for cardiovascular disease: high risk, <4%; intermediate risk, 4% to 8%; and low risk, >8%. DESIGN: Cross-sectional descriptive study. SETTING: Multicenter trial. PATIENTS OR OTHER PARTICIPANTS: Deidentified data including complete erythrocyte fatty acid profile from the 2017-2018 season, age at time of testing, height, weight, and ethnicity were collected from 404 athletes. MAIN OUTCOME MEASURE(S): Omega-3 Index. RESULTS: About 34% of athletes (n = 138) had an Omega-3 Index considered high risk (<4%), and 66% (n = 266) had a risk considered intermediate (4%-8%). None had a low-risk Omega-3 Index. CONCLUSIONS: The Omega-3 Index is a simple, minimally invasive test of ω-3 FA status. Our data indicate that football athletes may be deficient in the ω-3 FAs DHA and EPA. The fact that no athlete had an Omega-3 Index associated with low risk suggests football athletes may be at increased risk for cardiovascular disease in later life.


Asunto(s)
Ácidos Grasos Omega-3/metabolismo , Fútbol Americano/fisiología , Atletas , Estudios Transversales , Dieta , Ácidos Docosahexaenoicos/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/metabolismo , Eritrocitos/química , Femenino , Humanos , Masculino , Estudios Retrospectivos , Universidades , Adulto Joven
8.
Sports Med ; 48(Suppl 1): 39-52, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29368186

RESUMEN

Even in the presence of underreporting, sports-related concussions/mild traumatic brain injuries (mTBI) are on the rise. In the absence of proper diagnosis, an athlete may return to play prior to full recovery, increasing the risk of second-impact syndrome or protracted symptoms. Recent evidence has demonstrated that sub-concussive impacts, those sustained routinely in practice and competition, result in a quantifiable pathophysiological response and the accumulation of both concussive and sub-concussive impacts sustained over a lifetime of sports participation may lead to long-term neurological impairments and an increased risk of developing neurodegenerative diseases. The pathophysiological, neurometabolic, and neurochemical cascade that initiates subsequent to the injury is complex and involves multiple mechanisms. While pharmaceutical treatments may target one mechanism, specific nutrients and nutraceuticals have been discovered to impact several pathways, presenting a broader approach. Several studies have demonstrated the neuroprotective effect of nutritional supplementation in the treatment of mTBI. However, given that many concussions go unreported and sub-concussive impacts result in a pathophysiological response that, too, may contribute to long-term brain health, protection prior to impact is warranted. This review discusses the current literature regarding the role of nutritional supplements that, when provided before mTBI and traumatic brain injury, may provide neurological protection.


Asunto(s)
Atletas , Conmoción Encefálica , Traumatismos Craneocerebrales , Suplementos Dietéticos , Fármacos Neuroprotectores , Animales , Traumatismos en Atletas , Ratas , Deportes
9.
J Int Soc Sports Nutr ; 14: 29, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28811750

RESUMEN

BACKGROUND: The purpose was to survey dietary habits (DH) and nutrient timing (NT) practices of baseball student-athletes (mean ± SD; 20.7 ± 1.4 yr.) from three NCAA Division I institutions, and examine the effect of a sports dietitian (SD) in regard to nutrition practices. METHODS: Descriptive statistics and Pearson X2 analyses were run. Responses on 10 DH and 5 NT items differed (p ≤ 0.10) between athletes who sought dietary planning from a SD (n = 36) versus those who consulted a strength and conditioning coach (SCC, n = 42). RESULTS: In regard to DH items, the SD group found it easier to eat before activity (92% vs. 71%, p = 0.03), did not consume fast food (31% vs. 14%, p = 0.02), caffeinated beverages (57% vs. 46%, p = 0.02), or soda (56% vs. 37%, p = 0.10), prepared their own meals more often (86% vs. 73%, p = 0.07), and took daily multi-vitamins (56% vs. 32%, p = 0.02). The SCC group ate more at burger locations (21% vs. 6%, p = 0.02). In regard to NT items, the SD group ate breakfast before training/lifting sessions (67% vs. 37%, p = 0.02), and had post-workout nutrition options provided (61% vs. 27%, p = 0.01). The SCC group reported pre-competition meals of fast food (58% vs. 45%, p = 0.01), and sport coaches who were less aware of healthy food options (39% vs. 65%, p = 0.05). CONCLUSIONS: The SD is as a valuable asset to an intercollegiate athletics program. In the current study, athletes from the SD group consumed less high calorie/low nutrient dense items, ate before exercise, and consumed healthier options post-exercise. The presence of a SD was linked to provision of healthier food options during team trips. The evidence-based eating strategies and dietary plan provided by a SD may lead to improved performance and recovery.


Asunto(s)
Béisbol , Nutricionistas , Fenómenos Fisiológicos en la Nutrición Deportiva , Adolescente , Atletas , Estudios Transversales , Dieta Saludable , Humanos , Masculino , Necesidades Nutricionales , Universidades , Adulto Joven
10.
Nutrients ; 8(10)2016 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-27754427

RESUMEN

Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus (S.) thermophilus FP4 and Bifidobacterium (B.) breve BR03 at 5 bn live cells (AFU) concentration each, or a placebo, daily for 3 weeks prior to muscle-damaging exercise (ClinicalTrials.gov NCT02520583). Isometric strength, muscle soreness, range of motion and girth, and blood interleukin-6 (IL-6) and creatine kinase (CK) concentrations were measured from pre- to 72 h post-exercise. Statistical analysis was via mixed models and magnitude-based inference to the standardized difference. Probiotic supplementation resulted in an overall decrease in circulating IL-6, which was sustained to 48 h post-exercise. In addition, probiotic supplementation likely enhanced isometric average peak torque production at 24 to 72 h into the recovery period following exercise (probiotic-placebo point effect ±90% CI: 24 h, 11% ± 7%; 48 h, 12% ± 18%; 72 h, 8% ± 8%). Probiotics also likely moderately increased resting arm angle at 24 h (2.4% ± 2.0%) and 48 h (1.9% ± 1.9%) following exercise, but effects on soreness and flexed arm angle and CK were unclear. These data suggest that dietary supplementation with probiotic strains S. thermophilus FP4 and B. breve BR03 attenuates performance decrements and muscle tension in the days following muscle-damaging exercise.


Asunto(s)
Rendimiento Atlético , Bifidobacterium breve , Mialgia/prevención & control , Probióticos , Rango del Movimiento Articular , Entrenamiento de Fuerza , Streptococcus thermophilus , Adulto , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Músculo Esquelético , Adulto Joven
11.
J Int Soc Sports Nutr ; 13: 11, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26962303

RESUMEN

BACKGROUND: Multi-ingredient pre-workout supplements (MIPS) are popular among resistance trained individuals. Previous research has indicated that acute MIPS ingestion may increase muscular endurance when using a hypertrophy-based protocol but less is known in regard to their effects on strength performance and high intensity running capacity. Therefore, the purpose was to determine if short-term, MIPS ingestion influences strength performance and anaerobic running capacity. METHODS: In a double-blind, randomized, placebo controlled, crossover design; 12 males (19 ± 1 yrs.; 180 ± 12 cm; 89.3 ± 11 kg; 13.6 ± 4.9 %BF) had their body composition assessed followed by 5-repetition maximum (5RM) determination of back squat (BS; 119.3 ± 17.7 kg) and bench press (BP; 92.1 ± 17.8 kg) exercises. On two separate occasions subjects ingested a MIPS or a placebo (P) 30-minutes prior to performing a counter movement vertical jump test, 5 sets of 5 repetitions at 85 % of 5RM of BS and BP, followed by a single set to failure, and an anaerobic capacity sprint test to assess peak and mean power. Subjective markers of energy levels and fatigue were also assessed. Subjects returned one week later for a second testing session using counter treatment. RESULTS: MIPS resulted in a greater number of repetitions performed in the final set to failure in the BP (MIPS, 9.8 ± 1.7 repetitions; P, 9.1 ± 2; p = 0.03, d = 0.38), which led to a greater total volume load (set x repetitions x load) in the MIPS (753 ± 211 kg) compared to P (710 ± 226 kg; p =0.03, d = .20). MIPS ingestion improved subjective markers of fatigue (p = 0.01, d = 3.78) and alertness (p = 0.048, d = 2.72) following a bout of resistance training. An increase in mean power was observed in the MIPS condition (p = 0.03, d = 0.25) during the anaerobic sprint test. CONCLUSION: Results suggest that acute ingestion of a MIPS study may increase upper body muscular endurance. In addition, acute MIPS ingestion improved mean power output during an anaerobic capacity sprint test. However, the practical significance of these performance related outcomes may be minimal due to the small effect sizes observed. MIPS ingestion does appear to positively influence subjective markers of fatigue and alertness during high-intensity exercise.


Asunto(s)
Umbral Anaerobio/fisiología , Suplementos Dietéticos , Músculo Esquelético/fisiología , Resistencia Física/fisiología , Entrenamiento de Fuerza , Umbral Anaerobio/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Alimentos Formulados , Humanos , Masculino , Resistencia Física/efectos de los fármacos , Entrenamiento de Fuerza/métodos , Fenómenos Fisiológicos en la Nutrición Deportiva , Resultado del Tratamiento , Adulto Joven
12.
Med Sci Sports Exerc ; 48(6): 974-82, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26765633

RESUMEN

PURPOSE: American football athletes are exposed to subconcussive impacts over the course of the season resulting in elevations in serum neurofilament light (NFL), a biomarker of axonal injury. Docosahexaenoic acid (DHA) has been reported to reduce axonal trauma associated with traumatic brain injury in rodent models. However, the optimal dose in American football athletes is unknown. This study examined the effect of differing doses of DHA on serum NFL over the course of a season of American football. METHODS: In a randomized, double-blind, placebo-controlled, parallel design, 81 National Collegiate Athletic Association Division I American football athletes were assigned to ingest either 2, 4, 6 g·d of DHA or placebo. Blood was sampled at specific times over the course of 189 d, coincident with changes in intensity, hours of contact, and likely changes in head impacts. Standardized magnitude-based inference was used to define outcomes. RESULTS: DHA supplementation increased plasma DHA in a dose-dependent manner (2 g·d: mean difference from baseline; ±90% CL; 2 g·d: 1.3; ±0.6; 4 g·d: 1.6; ±0.7%; 6 g·d: 2.8; ±1.2%). Serum NFL increased to a greater extent in starters (area under the curve, 1995 ± 1383 pg·mL) versus nonstarters (1398 ± 581 pg·mL; P = 0.024). Irrespective of dose, supplemental DHA likely attenuated serum NFL coincident with increases in serum NFL by likely small and moderate magnitude (effect size = 0.4-0.7). CONCLUSIONS: Findings from this study, the first large-scale study examining potential prophylactic use of DHA in American football athletes, include identification of optimal dose of DHA, suggesting a neuroprotective effect of DHA supplementation.


Asunto(s)
Biomarcadores/sangre , Conmoción Encefálica/sangre , Suplementos Dietéticos , Ácidos Docosahexaenoicos/administración & dosificación , Fútbol Americano/lesiones , Proteínas de Neurofilamentos/sangre , Conmoción Encefálica/prevención & control , Ácidos Docosahexaenoicos/sangre , Método Doble Ciego , Humanos
13.
Int J Sport Nutr Exerc Metab ; 23(3): 252-8, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23164647

RESUMEN

PURPOSE: To determine the effects of creatine supplementation on blood lactate during incremental cycling exercise. METHODS: Thirteen male subjects (M ± SD 23 ± 2 yr, 178.0 ± 8.1 cm, 86.3 ± 16.0 kg, 24% ± 9% body fat) performed a maximal, incremental cycling test to exhaustion before (Pre) and after (Post) 6 d of creatine supplementation (4 doses/d of 5 g creatine + 15 g glucose). Blood lactate was measured at the end of each exercise stage during the protocol, and the lactate threshold was determined as the stage before achieving 4 mmol/L. Lactate concentrations during the incremental test were analyzed using a 2 (condition) × 6 (exercise stage) repeated-measures ANOVA. Differences in power at lactate threshold, power at exhaustion, and total exercise time were determined by paired t tests and are presented as M ± SD. RESULTS: Lactate concentrations were reduced during exercise after supplementation, demonstrating a significant condition effect (p = .041). There was a tendency for increased power at the lactate threshold (Pre 128 ± 45 W, Post 143 ± 26 W; p = .11). Total time to fatigue approached significant increases (Pre 22.6 ± 3.2 min, Post 23.3 ± 3.3 min; p = .056), as did maximal power output (Pre 212.5 ± 32.5 W, Post 220 ± 34.6 W; p = .082). CONCLUSIONS: Our findings demonstrate that creatine supplementation decreases lactate during incremental cycling exercise and tends to raise lactate threshold. Therefore, creatine supplementation could potentially benefit endurance athletes.


Asunto(s)
Ciclismo/fisiología , Creatina/administración & dosificación , Suplementos Dietéticos , Ácido Láctico/sangre , Administración Oral , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Músculo Esquelético/efectos de los fármacos , Consumo de Oxígeno , Resistencia Física/efectos de los fármacos , Adulto Joven
14.
Clin J Sport Med ; 22(5): 436-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22805182

RESUMEN

OBJECTIVE: To evaluate the relationship between body mass index (BMI) and %body fat (%Fat) in collegiate football athletes (FBA) compared with age-matched/gender-matched general population volunteers (comparison group, CG) and compare body composition and overweight/obese frequencies by BMI between FBA and CG. DESIGN: Cross-sectional. SETTING: Two Division I-A (D-IA) universities in Texas. Integrative Health Technologies (San Antonio, Texas) laboratory. PARTICIPANTS: Football athletes (n = 156, 20.0 ± 1.3 years, 185.6 ± 6.5cm, 103.3 ± 20.4 kg). Comparison group (n = 260, 21.5 ± 2.7 years, 179.0 ± 7.6 cm, 86.3 ± 20.9 kg). STATISTICAL ANALYSIS: Body mass index and bone densitrometry (DEXA) body composition were assessed. Regression was used to predict %Fat from BMI in CG and FBA. To compare %Fat, fat mass (FM), fat-free mass (FFM), and weight (WT) between CG, FBA, linemen, and non-linemen, 1 × 4 analysis of variance was used. Chi-square analysis was used to compare the frequency of BMI ≥25 between groups. RESULTS: Body mass index differently predicted %Fat for CG (r = 0.643, SE = 6.258) and FBA (r =0.769, SE = 4.416). Body mass index cutoffs for overweight/obese corresponded to the following %Fat in each group [BMI ≥25 = 19.9% (CG) and 11.1% (FBA); BMI ≥30 = 27.3% (CG) and 20.2% (FBA)]. Football athletes had significantly higher WT, BMI, FFM, and frequency of BMI ≥25 with lower %Fat and FM than CG (α < 0.05). Linemen had the highest WT, BMI, FFM, %Fat, and frequency of BMI ≥25. CONCLUSIONS: The relationship between BMI and %Fat differed between CG and FBA. Using current BMI thresholds for obesity in FBA may result in misleading inferences about health risk.


Asunto(s)
Atletas/estadística & datos numéricos , Índice de Masa Corporal , Fútbol Americano/fisiología , Obesidad/diagnóstico , Absorciometría de Fotón , Adolescente , Adulto , Composición Corporal , Estudios Transversales , Humanos , Masculino , Obesidad/epidemiología , Estudiantes/estadística & datos numéricos , Texas/epidemiología , Adulto Joven
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