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1.
Int J Esports ; 20232023.
Artículo en Inglés | MEDLINE | ID: mdl-38223751

RESUMEN

Aims: This study aimed to holistically assess the physical and cognitive attributes of esport athletes. Methods and Results: Forty-six adults between 18 and 32 years old with experience playing videogames were enrolled in this study. Participants completed assessments in five areas: demographics, self-report questionnaires, cognitive performance, physical performance, and gaming performance. Participants self-reported Overwatch ranking and physical activity participation (Pediatric Physical Activity Measure), and grip strength was measured with a handheld dynamometer. Seven domains of physical, mental, and social health and well-being were measured with the Patient Reported Outcomes Measurement Information System (PROMIS-29). The List Sorting Working Memory Test and Picture Sequence Memory Test from the National Institutes of Health (NIH) Toolbox Cognition Batteries were used to measure cognitive performance. Finally, esports performance was measured using a series of tasks through Alienware Academy and AIM Booster to record accuracy, reaction time, and targets hit. Participants were separated into high and low ranking groups for comparisons. This sample of esport athletes was similar to the general population for grip strength, each of the PROMIS-29 metrics, the List Sorting Working Memory Test, and the Picture Sequence Memory Test. Reaction time was the variable with the only significant difference between ranking groups. Conclusion: This study represents a primary investigation of esport athletes using a holistic approach. By incorporating physical and cognitive components, the most important factors to esport athletes' health and performance can be better understood and applied.

2.
Med Sci Sports Exerc ; 54(8): 1371-1381, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35389942

RESUMEN

PURPOSE: The aim of the present investigation was to determine whether a 1-h floatation-restricted environmental stimulation therapy (floatation-REST) session could augment recovery from high-intensity resistance exercise (6 × 10 back squats, 2-min rest) known to induce significant metabolic, adrenergic, and mechanical stress. METHODS: Eleven healthy resistance-trained males (age, 22.5 ± 2.3 yr; height, 176.4 ± 6.0 cm; weight, 85.7 ± 6.2 kg; back squat one-repetition maximum, 153.1 ± 20.1 kg; strength-to-weight ratio, 1.8 ± 0.2) completed the within-subject, crossover controlled study design. Participants completed two exercise testing blocks separated by a 2-wk washout. In one block, the high-intensity resistance exercise protocol was followed by a 1-h floatation-REST session, whereas recovery in the alternate block consisted of a passive sensory-stimulating control. Markers of metabolic stress, neuroendocrine signaling, structural damage, inflammation, and perceptions of soreness, mood state, and fatigue were assessed over a 48-h recovery window. RESULTS: Floatation-REST significantly attenuated muscle soreness across recovery ( P = 0.035) with greatest treatment difference immediately after the intervention ( P = 0.002, effect size (ES) = 1.3). Significant differences in norepinephrine ( P = 0.028, ES = 0.81) and testosterone ( P = 0.028, ES = 0.81) immediately after treatment revealed the modification of neuroendocrine signaling pathways, which were accompanied by greater improvements in mood disturbance ( P = 0.029, ES = 0.81) and fatigue ( P = 0.001, ES = 1.04). CONCLUSIONS: Because no adverse effects and significant and meaningful benefits were observed, floatation-REST may prove a valuable intervention for managing soreness and enhancing performance readiness after exercise.


Asunto(s)
Entrenamiento de Fuerza , Adulto , Ejercicio Físico/fisiología , Fatiga/metabolismo , Humanos , Masculino , Músculo Esquelético/fisiología , Mialgia/etiología , Entrenamiento de Fuerza/métodos , Adulto Joven
3.
Nutrients ; 13(6)2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34198888

RESUMEN

BACKGROUND: Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. OBJECTIVE: We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. METHODS: We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based 'Run-In' diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. RESULTS: Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. CONCLUSIONS: These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.


Asunto(s)
Mantequilla , Colesterol/sangre , Dieta/métodos , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Aceite de Palma/administración & dosificación , Adulto , Anciano , Estudios Cruzados , Dieta/efectos adversos , Dieta de Carga de Carbohidratos/efectos adversos , Dieta de Carga de Carbohidratos/métodos , Dieta Baja en Carbohidratos/efectos adversos , Dieta Baja en Carbohidratos/métodos , Dieta con Restricción de Grasas/efectos adversos , Dieta con Restricción de Grasas/métodos , Dieta Alta en Grasa/efectos adversos , Dieta Alta en Grasa/métodos , Femenino , Voluntarios Sanos , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Aceite de Palma/química , Adulto Joven
4.
Nutrients ; 13(3)2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33802651

RESUMEN

Ketogenic diets (KDs) often contain high levels of saturated fat, which may increase liver fat, but the lower carbohydrate intake may have the opposite effect. Using a controlled feeding design, we compared liver fat responses to a hypocaloric KD with a placebo (PL) versus an energy-matched low-fat diet (LFD) in overweight adults. We also examined the added effect of a ketone supplement (KS). Overweight adults were randomized to a 6-week KD (KD + PL) or a KD with KS (KD + KS); an LFD group was recruited separately. All diets were estimated to provide 75% of energy expenditure. Weight loss was similar between groups (p > 0.05). Liver fat assessed by magnetic resonance imaging decreased after 6 week (p = 0.004) with no group differences (p > 0.05). A subset with nonalcoholic fatty liver disease (NAFLD) (liver fat > 5%, n = 12) showed a greater reduction in liver fat, but no group differences. In KD participants with NAFLD, 92% of the variability in change in liver fat was explained by baseline liver fat (p < 0.001). A short-term hypocaloric KD high in saturated fat does not adversely impact liver health and is not impacted by exogenous ketones. Hypocaloric low-fat and KDs can both be used in the short-term to significantly reduce liver fat in individuals with NAFLD.


Asunto(s)
Dieta con Restricción de Grasas , Dieta Cetogénica , Suplementos Dietéticos , Grasas/análisis , Cetonas/uso terapéutico , Hígado/química , Sobrepeso/dietoterapia , Adulto , Dieta con Restricción de Grasas/métodos , Dieta Cetogénica/métodos , Grasas/metabolismo , Femenino , Humanos , Hígado/diagnóstico por imagen , Hígado/metabolismo , Imagen por Resonancia Magnética , Masculino , Sobrepeso/metabolismo
5.
Growth Horm IGF Res ; 55: 101355, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33032163

RESUMEN

OBJECTIVE: The purpose of this study was to examine the influence of a novel "floatation-restricted environmental stimulation therapy" (floatation-REST) on growth hormone responses to an intense resistance exercise stress. DESIGN: Nine resistance trained men (age: 23.4 ±â€¯2.5 yrs.; height: 175.3 ±â€¯5.4 cm; body mass: 85.3 ±â€¯7.9 kg) completed a balanced, crossover-controlled study design with two identical exercise trials, differing only in post-exercise recovery intervention (i.e., control or floatation-REST). A two-week washout period was used between experimental conditions. Plasma lactate was measured pre-exercise, immediately post-exercise and after the 1 h. recovery interventions. Plasma iGH was measured pre-exercise, immediately-post exercise, and after the recovery intervention, as well as 24 h and 48 h after the exercise test. The bGH-L was measured only at pre-exercise and following each recovery intervention. RESULTS: For both experimental conditions, a significant (P ≤ 0.05) increase in lactate concentrations were observed immediately post-exercise (~14 mmol • L-1) and remained slightly elevated after the recovery condition. The same pattern of responses was observed for iGH with no differences from resting values at 24 and 48 h of recovery. The bGH-L showed no exercise-induced changes following recovery with either treatment condition, however concentration values were dramatically lower than ever reported. CONCLUSION: The use of floatation-REST therapy immediately following intense resistance exercise does not appear to influence anterior pituitary function in highly resistance trained men. However, the lower values of bGH suggest dramatically different molecular processing mechanisms at work in this highly trained population.


Asunto(s)
Ejercicio Físico , Hormona de Crecimiento Humana/sangre , Hidrocortisona/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Ácido Láctico/sangre , Recuperación de la Función , Entrenamiento de Fuerza , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios Cruzados , Estudios de Seguimiento , Humanos , Masculino , Pronóstico , Privación Sensorial , Adulto Joven
6.
J Am Coll Nutr ; 39(4): 290-300, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32330107

RESUMEN

Background: Acute ingestion of ketone supplements alters metabolism and potentially exercise performance. No studies to date have evaluated the impact of co-ingestion of ketone salts with caffeine and amino acids on high intensity exercise performance, and no data exists in Keto-Adapted individuals.Methods: We tested the performance and metabolic effects of a pre-workout supplement containing beta-hydroxybutyrate (BHB) salts, caffeine, and amino acids (KCA) in recreationally-active adults habitually consuming a mixed diet (Keto-Naïve; n = 12) or a ketogenic diet (Keto-Adapted; n = 12). In a randomized and balanced manner, subjects consumed either the KCA consisting of ∼7 g BHB (72% R-BHB and 28% S-BHB) with ∼100 mg of caffeine, and amino acids (leucine and taurine) or Water (control condition) 15 minutes prior to performing a staged cycle ergometer time to exhaustion test followed immediately by a 30 second Wingate test.Results: Circulating total BHB concentrations increased rapidly after KCA ingestion in KN (154 to 732 µM) and KA (848 to 1,973 µM) subjects and stayed elevated throughout recovery in both groups. Plasma S-BHB increased >20-fold 15 minutes after KCA ingestion in both groups and remained elevated throughout recovery. Compared to Water, KCA ingestion increased time to exhaustion 8.3% in Keto-Naïve and 9.8% in Keto-Adapted subjects (P < 0.001). There was no difference in power output during the Wingate test between trials. Peak lactate immediately after exercise was higher after KCA (∼14.9 vs 12.7 mM).Conclusion: These results indicate that pre-exercise ingestion of a moderate dose of R- and S-BHB salts combined with caffeine, leucine and taurine improves high-intensity exercise performance to a similar extent in both Keto-Adapted and Keto-Naïve individuals.


Asunto(s)
Ácido 3-Hidroxibutírico/administración & dosificación , Aminoácidos/administración & dosificación , Ciclismo/fisiología , Cafeína/administración & dosificación , Suplementos Dietéticos , Fenómenos Fisiológicos en la Nutrición Deportiva , Ácido 3-Hidroxibutírico/sangre , Adaptación Fisiológica , Adolescente , Adulto , Estudios Cruzados , Dieta Cetogénica , Ingestión de Alimentos/fisiología , Prueba de Esfuerzo , Femenino , Humanos , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Resistencia Física/efectos de los fármacos , Sales (Química)/farmacología , Adulto Joven
7.
Growth Horm IGF Res ; 50: 9-22, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31809882

RESUMEN

OBJECTIVE: To revisit a finding, first described in 1978, which documented existence of a pituitary growth factor that escaped detection by immunoassay, but which was active in the established rat tibia GH bioassay. METHODS: We present a narrative review of the evolution of growth hormone complexity, and its bio-detectability, from a historical perspective. RESULTS: In humans under the age of 60, physical training (i.e. aerobic endurance and resistance training) are stressors which preferentially stimulate release of bioactive GH (bGH) into the blood. Neuroanatomical studies indicate a) that nerve fibers directly innervate the human anterior pituitary and b) that hind limb muscle afferents, in both humans and rats, also modulate plasma bGH. In the pituitary gland itself, molecular variants of GH, somatotroph heterogeneity and cell plasticity all appear to play a role in regulation of this growth factor. CONCLUSION: This review considers more recent findings on this often forgotten/neglected subject. Comparison testing of a) human plasma samples, b) sub-populations of separated rat pituitary somatotrophs or c) purified human pituitary peptides by GH bioassay vs immunoassay consistently yield conflicting results.


Asunto(s)
Ejercicio Físico/fisiología , Hormona de Crecimiento Humana/sangre , Somatotrofos/metabolismo , Vías Aferentes , Animales , Bioensayo/métodos , Plasticidad de la Célula , Entrenamiento Aeróbico , Hormona del Crecimiento/sangre , Hormona del Crecimiento/metabolismo , Hormona de Crecimiento Humana/metabolismo , Humanos , Hipotálamo/metabolismo , Inmunoensayo/métodos , Músculo Esquelético/inervación , Condicionamiento Físico Animal/fisiología , Adenohipófisis/inervación , Ratas , Entrenamiento de Fuerza , Somatotrofos/citología
8.
J Strength Cond Res ; 34(2): 313-322, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31490429

RESUMEN

Rissanen, JA, Häkkinen, A, Laukkanen, J, Kraemer, WJ, and Häkkinen, K. Acute neuromuscular and hormonal responses to different exercise loadings followed by a sauna. J Strength Cond Res 34(2): 313-322, 2020-The purpose of this study was to investigate acute responses of endurance (E + SA), strength (S + SA), and combined endurance and strength exercise (C + SA) followed by a traditional sauna bath (70° C, 18% relative humidity) on neuromuscular performance and serum hormone concentrations. Twenty-seven recreationally physically active men who were experienced with taking a sauna participated in the study. All the subjects performed a sauna bath only (SA) first as a control measurement followed by S + SA and E + SA (paired matched randomization) and C + SA. Subjects were measured PRE (before exercise), MID (immediately after exercise and before sauna), POST (after sauna), POST30min (30 minutes after sauna), and POST24h (24 hours after PRE). Maximal isometric leg press (ILPFmax) and bench press (IBPFmax) forces, maximal rate of force development (RFD) and countermovement vertical jump (CMVJ), serum testosterone (TES), cortisol (COR), and 22-kD growth hormone (GH22kD) concentrations were measured. All exercise loadings followed by a sauna decreased ILPFmax (-9 to -15%) and RFD (-20 to -26%) in POST. ILPFmax, RFD, and CMVJ remained at significantly (p ≤ 0.05) lowered levels after S + SA in POST24h. IBPFmax decreased in POST in S + SA and C + SA and remained lowered in POST24h. SA decreased ILPFmax and IBPFmax in POST and POST30min and remained lowered in ILPFmax (-4.1%) at POST24h. GH22kD, TES, and COR elevated significantly in all loadings measured in the afternoon in MID. SA only led to an elevation (15%) in TES in POST. The strength exercise followed by a sauna was the most fatiguing protocol for the neuromuscular performance. Traditional sauna bathing itself seems to be strenuous loading, and it may not be recommended 24 hours before the next training session. A sauna bath after the loadings did not further change the hormonal responses recorded after the exercise loadings.


Asunto(s)
Ejercicio Físico/fisiología , Esfuerzo Físico/fisiología , Baño de Vapor , Adulto , Temperatura Corporal/fisiología , Hormona de Crecimiento Humana/sangre , Humanos , Hidrocortisona/sangre , Ácido Láctico/sangre , Masculino , Distribución Aleatoria , Testosterona/sangre , Adulto Joven
9.
J Strength Cond Res ; 33(8): 2019-2052, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31343601

RESUMEN

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.


Asunto(s)
Envejecimiento/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Anciano , Anciano de 80 o más Años , Femenino , Fragilidad/fisiopatología , Fragilidad/prevención & control , Humanos , Masculino , Rendimiento Físico Funcional , Calidad de Vida , Sarcopenia/fisiopatología , Sarcopenia/prevención & control
10.
J Med Food ; 21(1): 104-112, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28981384

RESUMEN

The effect of GINST15, an enzyme fermented ginseng supplement, on hormonal and inflammatory responses to physical stress in humans is unknown. The purpose of this investigation was to examine the constitutive and stress-induced effects of GINST15 supplement on hypo-pituitary-adrenal (HPA) and antioxidant activity in addition to muscle damage. Ten women (age: 38.7 ± 7.8 years; height: 163.81 ± 4.4 cm; body mass 76.0 ± 11.6 kg) and nine men (age: 41.2. ± 9.7 years; height: 177.4 ± 5.3 cm; body mass: 88.5 ± 5.0 kg) participated in a double-blinded, placebo-controlled, counterbalanced within-group study. Participants completed three 14-day treatment cycles with different doses (high: 960 mg; low: 160 mg; placebo: 0 mg) separated by a 1-week washout period. At the end of treatment, physical stress was imposed with intense resistance exercise work stress. Participants provided blood at rest and various time points after exercise (immediately [IP], 30 min [30], 60 min [60], 24 h [+24HR]). Cortisol (CORT), superoxide dismutase (SOD), total glutathione, nonspecific antioxidant activity, total antioxidant power (TAP), and creatine kinase were measured. GINST15 supplementation produced stress-inducible dose-dependent reductions in circulating cortisol and increased enzymatic and nonspecific antioxidant activity. Twenty-four hours after intense exercise, a high dose GINST15, a bioactive ginsenoside metabolite, significantly reduces muscle damage and HPA responses to physical stress in humans; these effects may result from increased antioxidant expression.


Asunto(s)
Suplementos Dietéticos/análisis , Ejercicio Físico , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Panax/química , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Adulto , Femenino , Glutatión/metabolismo , Humanos , Hidrocortisona/sangre , Sistema Hipotálamo-Hipofisario/metabolismo , Malondialdehído/metabolismo , Persona de Mediana Edad , Sistema Hipófiso-Suprarrenal/metabolismo , República de Corea , Entrenamiento de Fuerza
11.
J Am Coll Nutr ; 35(8): 657-669, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27484437

RESUMEN

OBJECTIVE: The purpose of this study was to examine the metabolic, lipolytic, and cardiovascular responses to supplementation with p-synephrine alone and in combination with caffeine during resistance exercise (RE). METHODS: Twelve healthy men performed a control RE protocol (6 × 10 repetitions of squats) and were randomly assigned (using a double-blind crossover design with random protocol sequencing) to a supplement sequence: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). Subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 minutes, performed the RE protocol, and sat quietly for 30 minutes. Blood samples were collected at rest (T1), after sitting quietly for 45 minutes (T2), immediately following RE (T3), and 15 minutes (T4) and 30 minutes (T5) postexercise. Oxygen consumption (VO2) and heart rate (HR) data were collected throughout. RESULTS: Serum glycerol was significantly elevated at T2 only in S and SCF and T3 to T5 in all treatments. Nonesterified fatty acid (NEFA) concentrations did not differ between treatments. Plasma glucose was significantly elevated compared to T1 with highest area under the curve values seen in SCF. Mean VO2 and energy expenditure (EE) were significantly higher in S and SCF through 30 minutes postexercise. Fat oxidation rates favored S and SCF between 25 and 30 minutes postexercise. Mean HR during RE was significantly highest in SCF. CONCLUSIONS: Supplementation with S and SCF increases lipolysis primarily at rest and increases VO2, EE, and fat oxidation rates 30 minutes following RE. No HR changes were observed unless caffeine was added.


Asunto(s)
Cafeína/administración & dosificación , Sistema Cardiovascular/efectos de los fármacos , Ejercicio Físico/fisiología , Entrenamiento de Fuerza , Sinefrina/administración & dosificación , Adulto , Glucemia/análisis , Estudios Cruzados , Suplementos Dietéticos , Método Doble Ciego , Metabolismo Energético/efectos de los fármacos , Ácidos Grasos no Esterificados/sangre , Glicerol/sangre , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Lipólisis/efectos de los fármacos , Masculino , Metabolismo/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos
12.
J Strength Cond Res ; 30(6): 1491-509, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26933920

RESUMEN

There has recently been a growing interest in long-term athletic development for youth. Because of their unique physical, psychological, and social differences, children and adolescents should engage in appropriately prescribed exercise programs that promote physical development to prevent injury and enhance fitness behaviors that can be retained later in life. Irrespective of whether a child is involved in organized sport or engages in recreational physical activity, there remains a need to adopt a structured, logical, and evidence-based approach to the long-term development of athleticism. This is of particular importance considering the alarmingly high number of youth who fail to meet global physical activity recommendations and consequently present with negative health profiles. However, appropriate exercise prescription is also crucial for those young athletes who are physically underprepared and at risk of overuse injury because of high volumes of competition and an absence of preparatory conditioning. Whether the child accumulates insufficient or excessive amounts of exercise, or falls somewhere between these opposing ends of the spectrum, it is generally accepted that the young bodies of modern day youth are often ill-prepared to tolerate the rigors of sports or physical activity. All youth should engage in regular physical activity and thus should be viewed as "athletes" and afforded the opportunity to enhance athleticism in an individualized, holistic, and child-centered manner. Because of emerging interest in long-term athletic development, an authorship team was tasked on behalf of the National Strength and Conditioning Association (NSCA) to critically synthesize existing literature and current practices within the field and to compose a relevant position statement. This document was subsequently reviewed and formally ratified by the NSCA Board of Directors. A list of 10 pillars of successful long-term athletic development are presented, which summarize the key recommendations detailed within the position statement. With these pillars in place, it is believed that the NSCA can (a) help foster a more unified and holistic approach to long-term athletic development, (b) promote the benefits of a lifetime of healthy physical activity, and


Asunto(s)
Atletas , Ejercicio Físico/fisiología , Deportes/fisiología , Adolescente , Desarrollo del Adolescente , Niño , Trastornos de Traumas Acumulados/prevención & control , Femenino , Humanos , Masculino
13.
J Am Coll Nutr ; 35(2): 100-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26885762

RESUMEN

OBJECTIVE: Nitrate-rich (NR) supplements can enhance exercise performance by improving neuromuscular function and the aerobic cost of exercise. However, little is known about the effects of nitrate on dynamic, multijoint resistance exercise. METHODS: Fourteen resistance-trained men (age, 21.1 ± 0.9 years; height, 173.2 ± 2.9 cm: body mass, 77.6 ± 4.3 kg; squat one-repetition maximum [1RM], 127.5 ± 18.8 kg) participated in a randomized, double-blind, crossover experiment. Subjects consumed an NR or nitrate-poor (NP) supplement for 3 days, performed a bout of heavy resistance exercise, completed a washout, and then repeated the procedures with the remaining supplement. Before, during, and after exercise, individual and gross motor unit efficiency was assessed during isometric and dynamic muscle contractions. In addition, we compared physical performance, heart rate, lactate, and oxygen consumption (VO2). RESULTS: Nitrate-rich supplementation resulted in lower initial muscle firing rates at rest and lower mean and maximum firing rates over the course of fatiguing exercise. Nitrate-poor supplementation was accompanied by increased mean and maximum firing rates by the end of exercise and lower initial firing rates. In addition, NR supplementation resulted in higher mean peak electromyography (EMG) amplitudes. Heart rate, lactate, and physical performance did not differ by treatment, but oxygen consumption increased more frequently when the NP supplement was consumed. CONCLUSION: Supplementation with an NR beetroot extract-based supplement provided neuromuscular advantages during metabolically taxing resistance exercise.


Asunto(s)
Suplementos Dietéticos/análisis , Ejercicio Físico/fisiología , Nitratos/farmacología , Reclutamiento Neurofisiológico/efectos de los fármacos , Beta vulgaris/química , Método Doble Ciego , Humanos , Masculino , Nitratos/administración & dosificación , Nitratos/química , Raíces de Plantas/química , Adulto Joven
14.
J Strength Cond Res ; 30(2): 569-78, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26270693

RESUMEN

Nucleotide supplementation can reduce postexercise immunosuppression and hypothalamic-pituitary axis (HPA) axis activation in endurance exercise models. Nucleotide supplementation may aid recovery from other exercise modalities, such as heavy resistance exercise. Thus, the purpose of this investigation was to investigate the effects of nucleotide supplementation on the acute cortisol and immune responses to heavy resistance exercise and its effects on recovery. A double-blinded, crossover, mixed methods design with 10 men and 10 women was used. Each performed an acute heavy resistance exercise protocol (AHREP) after a loading period with a nucleotide or placebo supplement. Before and after the AHREP, and at 24, 48, and 72 hours post, blood samples were analyzed for cortisol, myeloperoxidase (MPO), and absolute neutrophil, lymphocyte, and monocyte counts. Creatine kinase (CK) was analyzed before and 24, 48, and 72 hours after the AHREP. Performance measures, including peak back squat isometric force and peak countermovement jump power were also analyzed. Nucleotide supplementation resulted in significant (p ≤ 0.05) decreases in cortisol and MPO immediately after the AHREP, and significantly lower CK values 24 hours later. The AHREP significantly affected leukocyte counts; however, no treatment effects were observed. Greater isometric force was observed immediately after AHREP and at 24 hours and 48 hours with nucleotide supplementation. Nucleotide supplementation seems to attenuate muscle damage, HPA axis and immune system activation, and performance decrements after heavy resistance exercise.


Asunto(s)
Rendimiento Atlético/fisiología , Suplementos Dietéticos , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Nucleótidos/farmacología , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Entrenamiento de Fuerza , Estrés Fisiológico/efectos de los fármacos , Adulto , Biomarcadores/sangre , Creatina Quinasa/sangre , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Hidrocortisona/sangre , Sistema Hipotálamo-Hipofisario/fisiología , Masculino , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/fisiología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Nucleótidos/administración & dosificación , Sistema Hipófiso-Suprarrenal/fisiología , Estrés Fisiológico/fisiología , Adulto Joven
15.
J Int Soc Sports Nutr ; 12: 35, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26388707

RESUMEN

BACKGROUND: Little is known concerning the potential ergogenic effects of p-synephrine supplementation. Therefore, the purpose of the present study was to examine the effects of supplementation with p-synephrine alone and in combination with caffeine on free-weight resistance exercise performance. METHODS: Twelve healthy, college-aged men performed a control (CT) resistance exercise protocol consisting of 6 sets of squats for up to 10 repetitions per set using 80% of their one repetition-maximum (1RM) with 2 min of rest in between sets. Each subject was randomly assigned (in double-blind, balanced manner) to a treatment sequence consisting of use of 3 supplements: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). For each supplement treatment (separated by 1 week), subjects consumed the supplement for 3 days prior to each protocol and the morning of each protocol, and subsequently did not consume any supplements for 3 days following (i.e. wash-out period). On each protocol day, subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 min, performed the resistance exercise protocol, and sat quietly for 30 min post exercise. Performance (repetition number, force, velocity and power), blood lactate, and ratings of perceived exertion (RPE) data were collected during each protocol. RESULTS: Supplements SCF and S produced a significantly (P < 0.05) greater number of repetitions performed than CT (by 11.0 ± 8.0%) and P (by 6.0 ± 7.0%) and a 10.6 ± 12.0% greater increase in volume load per protocol than CT and P. Most of the differences were seen during the last 3 sets. Mean power and velocity for all 6 sets were significantly higher in SCF compared to CT and P by ~6.2 ± 8.0%. No supplement effects were observed in RPE or blood lactate, and no adverse side effects were observed or reported. CONCLUSIONS: S and SCF augmented resistance exercise performance (total repetitions, volume load) without increasing blood lactate or RPE. The addition of caffeine in SCF increased mean power and velocity of squat performance. These results indicate supplementation with S and SCF can enhance local muscle endurance during resistance exercise.


Asunto(s)
Cafeína/farmacología , Contracción Isométrica/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Entrenamiento de Fuerza , Sinefrina/farmacología , Rendimiento Atlético , Cafeína/administración & dosificación , Suplementos Dietéticos , Método Doble Ciego , Humanos , Contracción Isométrica/fisiología , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Consumo de Oxígeno , Resistencia Física/fisiología , Sinefrina/administración & dosificación , Adulto Joven
16.
J Am Coll Nutr ; 33(4): 247-55, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25140763

RESUMEN

PURPOSE: The purpose of this study was to determine the effects of a multinutritional supplement including amino acids, ß-hydroxy-ß-methylbutyrate (HMB), and carbohydrates on cytokine responses to resistance exercise and training. METHODS: Seventeen healthy, college-aged men were randomly assigned to a Muscle Armor™ (MA; Abbott Nutrition, Columbus, OH) or placebo supplement group and 12 weeks of resistance training. An acute resistance exercise protocol was administered at 0, 6, and 12 weeks of training. Venous blood samples at pre-, immediately post-, and 30-minutes postexercise were analyzed via bead multiplex immunoassay for 17 cytokines. RESULTS: After 12 weeks of training, the MA group exhibited decreased interferon-gamma (IFN-γ) and interleukin (IL)-10. IL-1ß differed by group at various times. Granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, IL-7, IL-8, IL-12p70, IL-13, IL-17, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1ß) changed over the 12-week training period but did not differ by group. CONCLUSIONS: Twelve weeks of resistance training alters the cytokine response to acute resistance exercise, and supplementation with HMB and amino acids appears to further augment this result.


Asunto(s)
Citocinas/sangre , Carbohidratos de la Dieta/administración & dosificación , Suplementos Dietéticos , Entrenamiento de Fuerza , Valeratos/administración & dosificación , Aminoácidos/administración & dosificación , Índice de Masa Corporal , Peso Corporal , Quimiocina CCL2/sangre , Quimiocina CCL4/sangre , Método Doble Ciego , Voluntarios Sanos , Humanos , Interferón gamma/sangre , Interleucina-10/sangre , Interleucina-13/sangre , Interleucina-1beta/sangre , Interleucina-6/sangre , Interleucina-8/sangre , Masculino , Micronutrientes/administración & dosificación , Evaluación Nutricional , Adulto Joven
17.
J Am Coll Nutr ; 32(1): 66-74, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24015701

RESUMEN

OBJECTIVE: For many resistance-trained men concerns exist regarding the production of estrogen with the consumption of soy protein when training for muscle strength and size. Thus, the purpose of this investigation was to examine the effects of soy and whey protein supplementation on sex hormones following an acute bout of heavy resistance exercise in resistance trained men. METHODS: Ten resistance-trained men (age 21.7 ± 2.8 [SD] years; height 175.0 ± 5.4 cm; weight 84.2 ± 9.1 kg) volunteered to participate in an investigation. Utilizing a within subject randomized crossover balanced placebo design, all subjects completed 3 experimental treatment conditions supplementing with whey protein isolate (WPI), soy protein isolate (SPI), and maltodextrin placebo control for 14 days with participants ingesting 20 g of their assigned supplement each morning at approximately the same time each day. Following supplementation, subjects performed an acute heavy resistance exercise test consisting of 6 sets of 10 repetitions in the squat exercise at 80% of the subject's one repetition maximum. RESULTS: This investigation observed lower testosterone responses following supplementation with soy protein in addition to a positive blunted cortisol response with the use of whey protein at some recovery time points. Although sex hormone binding globulin (SHBG) was proposed as a possible mechanism for understanding changes in androgen content, SHBG did not differ between experimental treatments. Importantly, there were no significant differences between groups in changes in estradiol concentrations. CONCLUSION: Our main findings demonstrate that 14 days of supplementation with soy protein does appear to partially blunt serum testosterone. In addition, whey influences the response of cortisol following an acute bout of resistance exercise by blunting its increase during recovery. Protein supplementation alters the physiological responses to a commonly used exercise modality with some differences due to the type of protein utilized.


Asunto(s)
Suplementos Dietéticos , Ejercicio Físico/fisiología , Hidrocortisona/sangre , Proteínas de la Leche/farmacología , Entrenamiento de Fuerza , Proteínas de Soja/farmacología , Testosterona/sangre , Adulto , Estudios Cruzados , Proteínas en la Dieta/farmacología , Estradiol/sangre , Prueba de Esfuerzo , Humanos , Masculino , Polisacáridos/farmacología , Globulina de Unión a Hormona Sexual/metabolismo , Glycine max/química , Proteína de Suero de Leche , Adulto Joven
18.
J Am Coll Nutr ; 32(2): 122-35, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24015719

RESUMEN

UNLABELLED: Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. OBJECTIVE: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22). METHODS: All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (~9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months. RESULTS: Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass⁻¹, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. CONCLUSIONS: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.


Asunto(s)
Suplementos Dietéticos , Proteínas de la Leche/administración & dosificación , Entrenamiento de Fuerza , Adulto , Aminoácidos/sangre , Índice de Masa Corporal , Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Método Doble Ciego , Femenino , Humanos , Leucina/sangre , Masculino , Proteínas Musculares/biosíntesis , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Estudios Prospectivos , Proteínas de Soja/administración & dosificación , Proteína de Suero de Leche , Adulto Joven
19.
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
20.
Nutr J ; 10: 90, 2011 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-21899733

RESUMEN

BACKGROUND: While exercise acts to combat inflammation and aging, the ability to exercise may itself be compromised by inflammation and inflammation's impact on muscle recovery and joint inflammation. A number of nutritional supplements have been shown to reduce inflammation and improve recovery. The purpose of the current investigation was to examine the effect of a multi-nutrient supplement containing branched chain amino acids, taurine, anti-inflammatory plant extracts, and B vitamins on inflammatory status, endothelial function, physical function, and mood in middle-aged individuals. METHODS: Thirty-one healthy and active men (N = 16, mean age 56 ± 6.0 yrs) and women (N = 15, mean age = 52 ± 7.5 yrs) participated in this investigation. Subjects completed one 28 day cycle of placebo supplementation and one 28 day cycle of multi-nutrient supplementation (separated by a one week washout period) in a balanced, randomized, double-blind, cross-over design. Subjects completed weekly perceptual logs (PROMIS-57, KOOS) and pre- and post- testing around the supplementation period. Testing consisted of brachial artery flow mediated dilation (FMD), blood measures, and physical performance on vertical jump, handgrip strength, and balance (dispersion from center of pressure). Significance for the investigation was p ≤ 0.05. RESULTS: IL-6 significantly decreased in both men (from 1.2 ± 0.2 to 0.7 ± 0.4 pg·mL(-1)) and women (from 1.16 ± 0.04 to 0.7 ± 0.4 pg·mL(-1)). Perceived energy also improved for both men (placebo: 1.8 ± 0.7; supplement: 3.7 ± 0.8 AUC) and women (placebo: 1.2 ± 0.7; supplement: 2.8 ± 0.8 AUC). Alpha-1-antichymotrypsin (from 108.9 ± 38.6 to 55.5 ± 22.2 ug·mL(-1)), Creatine Kinase (from 96 ± 34 to 67 ± 23 IU·L(-1)), general pain, and joint pain decreased in men only, while anxiety and balance (from 0.52 ± 0.13 to 0.45 ± 0.12 cm) improved in women only. Men showed increased performance in vertical jump power (from 2642 ± 244 to 3134 ± 282 W) and grip strength (from 42.1 ± 5.9 to 48.5 ± 4.9 kg). CONCLUSIONS: A multi-nutrient supplement is effective in improving inflammatory status in both men and women, markers of pain, joint pain, strength, and power in men only, and both anxiety and balance (a risk factor for hip fracture) in women. Therefore, a multi-nutrient supplement may help middle-aged individuals to prolong physical function and maintain a healthy, active lifestyle.


Asunto(s)
Suplementos Dietéticos , Inflamación/tratamiento farmacológico , Aptitud Física/fisiología , Envejecimiento , Creatina Quinasa/metabolismo , Método Doble Ciego , Ejercicio Físico , Femenino , Humanos , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , alfa 1-Antiquimotripsina/metabolismo
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