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1.
J Strength Cond Res ; 2024 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-39446676

RESUMEN

ABSTRACT: Curtis, M, Kupperman, N, Westbrook, J, Weltman, AL, Hart, J, and Hertel, J. Neuromuscular performance and the intensity of external training load during the preseason in National Collegiate Athletic Association Division I men's collegiate basketball players. J Strength Cond Res XX(X): 000-000, 2024-The aim of the study was to determine whether acute changes in neuromuscular performance can be detected through countermovement jumps (CMJs) conducted pre- and postpractice sessions in conditions of high or low intensity measured by microsensors technology. Using an observational repeated measures design, data were collected from 10 male collegiate basketball players. Countermovement jump data were collected before and after practice exposures over 4 weeks of preseason. Select CMJ kinetics were compared in conditions of high and low training load intensity to detect neuromuscular performance changes in displacement of the center of mass and kinetics. Kinetic measures were categorized as output, underpinning, and strategy-related variables. We investigated "output" defined as displacement (jump height [JH]), "underpinning" defined as force-related (mean eccentric force, mean concentric force, force at zero velocity), and "strategy" defined as time-related (countermovement depth [CMD], eccentric duration (EccDur), concentric duration [ConcDur]) variables. There were significant condition × time interactions in CMJ variables namely eccentric mean force (EccForce), force at zero velocity (Force@0), CMDepth, EccDur, and ConcDur. In conditions of high intensity, players had significant, but small decreases in EccForce and Force@0, with small increases in CMD, EccDur, and ConDur, respectively. However, there were no significant decreases in JH. High-intensity practice exposures did not impact neuromuscular performance specific to "output," suggesting that collegiate basketball athletes can maintain JH despite alterations in "underpinning" and "strategy-related" variables. This could have relevance in understanding how fatigue associated with higher-intensity training exposures may potentially alter jump strategy and force production capacities due to external load intensity in collegiate basketball athletes.

2.
Am J Physiol Endocrinol Metab ; 322(2): E101-E108, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34894721

RESUMEN

Arterial stiffness and endothelial dysfunction are both reported in children with type 1 diabetes (DM1) and may predict future cardiovascular events. In health, nitric oxide (NO) relaxes arteries and increases microvascular perfusion. The relationships between NO-dependent macro- and microvascular functional responses and arterial stiffness have not been studied in adolescents with DM1. Here, we assessed macro- and microvascular function in DM1 adolescents and age-matched controls at baseline and during an oral glucose challenge (OGTT). DM1 adolescents (n = 16) and controls (n = 14) were studied before and during an OGTT. At baseline, we measured: 1) large artery stiffness using both aortic augmentation index (AI) and carotid-femoral pulse wave velocity (cfPWV); 2) brachial flow-mediated dilation (FMD) and forearm endothelial function using postischemic flow velocity (PIFV); and 3) forearm muscle microvascular blood volume (MBV) using contrast-enhanced ultrasound. Following OGTT, AI, cfPWV, and MBV were reassessed at 60 min and MBV again at 120 min. Within individual and between-group, comparisons were made by paired and unpaired t tests or repeated measures ANOVA. Baseline FMD was lower (P = 0.02) in DM1. PWV at 0 and 60 min did not differ between groups. Baseline AI did not differ between groups but declined with OGTT only in controls (P = 0.02) and was lower than DM1 at 60 min (P < 0.03). Baseline MBV was comparable in DM1 and control groups, but declined in DM1 at 120 min (P = 0.01) and was lower than the control group (P < 0.03). There was an inverse correlation between plasma glucose and MBV at 120 min (r = -0.523, P < 0.01). No differences were noted between groups for V̇O2max (mL/min/kg), body fat (%), or body mass index (BMI). NO-dependent macro- and microvascular function, including FMD and AI, and microvascular perfusion, respectively, are impaired early in the course of DM1, precede increases of arterial stiffness, and may provide an early indicator of vascular risk.NEW & NOTEWORTHY This is the first study to show that type 1 diabetes impairs multiple nitric oxide-dependent vascular functions.


Asunto(s)
Arteria Braquial/fisiopatología , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/fisiopatología , Endotelio Vascular/fisiopatología , Óxido Nítrico/metabolismo , Rigidez Vascular , Adolescente , Velocidad del Flujo Sanguíneo , Glucemia/análisis , Estudios de Casos y Controles , Femenino , Antebrazo/irrigación sanguínea , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Músculo Esquelético/irrigación sanguínea , Análisis de la Onda del Pulso , Vasodilatación
3.
Mov Disord ; 35(6): 947-958, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32092190

RESUMEN

BACKGROUND: Sleep dysfunction is common and disabling in persons with Parkinson's Disease (PD). Exercise improves motor symptoms and subjective sleep quality in PD, but there are no published studies evaluating the impact of exercise on objective sleep outcomes. The goal of this study was to to determine if high-intensity exercise rehabilitation combining resistance training and body-weight interval training, compared with a sleep hygiene control improved objective sleep outcomes in PD. METHODS: Persons with PD (Hoehn & Yahr stages 2-3; aged ≥45 years, not in a regular exercise program) were randomized to exercise (supervised 3 times a week for 16 weeks; n = 27) or a sleep hygiene, no-exercise control (in-person discussion and monthly phone calls; n = 28). Participants underwent polysomnography at baseline and post-intervention. Change in sleep efficiency was the primary outcome, measured from baseline to post-intervention. Intervention effects were evaluated with general linear models with measurement of group × time interaction. As secondary outcomes, we evaluated changes in other aspects of sleep architecture and compared the effects of acute and chronic training on objective sleep outcomes. RESULTS: The exercise group showed significant improvement in sleep efficiency compared with the sleep hygiene group (group × time interaction: F = 16.0, P < 0.001, d = 1.08). Other parameters of sleep architecture also improved in exercise compared with sleep hygiene, including total sleep time, wake after sleep onset, and slow-wave sleep. Chronic but not acute exercise improved sleep efficiency compared with baseline. CONCLUSIONS: High-intensity exercise rehabilitation improves objective sleep outcomes in PD. Exercise is an effective nonpharmacological intervention to improve this disabling nonmotor symptom in PD. © 2020 International Parkinson and Movement Disorder Society.


Asunto(s)
Enfermedad de Parkinson , Trastornos del Sueño-Vigilia , Anciano , Terapia por Ejercicio , Objetivos , Humanos , Enfermedad de Parkinson/complicaciones , Polisomnografía , Sueño , Resultado del Tratamiento
4.
J Strength Cond Res ; 33(8): 2170-2176, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30703070

RESUMEN

Stine, KA, Moxey, JR, Gilbertson, NM, Malin, SK, and Weltman, AL. Effects of feedback type and personality on 2,000-m ergometer performance in female varsity collegiate rowers. J Strength Cond Res 33(8): 2170-2176, 2019-Rowing performance is routinely tested on ergometers, involving visual cues and verbal encouragement, whereas on-water rowing lacks the visual cues. Personality is also hypothesized to influence rowing performance. The purpose was to examine the effects of visual and verbal feedback and to determine the impact of personality on performance. Thirty-eight female collegiate rowers (body mass 75.0 ± 5.7 kg and height 176.6 ± 5.0 cm) were recruited. Participants were asked to complete a progressive continuous graded exercise test, body composition analysis, personality questionnaire (Neo five-factor inventory, version 3), and 2 randomly ordered 2000-m ergometer tests: routine verbal and visual vs. verbal only. Differences between the 2,000-m tests were analyzed with a paired t-test. The relationships among VO2max, body composition, and 2,000-m performance were analyzed with Pearson's Correlations. A 2 × 2 analysis of variance analyzed neuroticism, openness, agreeableness, and conscientiousness to investigate how personality impacted 2,000-m performance. Statistical significance was set to p ≤ 0.05. The combination of visual plus verbal feedback trended toward improving performance compared with the verbal feedback alone (430.3 ± 8.6, 431.6 ± 8.9 seconds, respectively). High neuroticism negatively impacted 2,000-m performance (p ≤ 0.05). Conscientiousness and agreeableness trended toward improved performance: as conscientiousness and agreeableness increase, time decreases. We conclude that the combination of verbal plus visual feedback tends to yield better 2,000-m performance and that highly conscientious, highly agreeable, and low neurotic athletes outperform their respective counterparts. Using visual plus verbal encouragement while simultaneously targeting personality factors may be a novel strategy to optimize rowers' training.


Asunto(s)
Rendimiento Atlético/fisiología , Composición Corporal/fisiología , Retroalimentación , Personalidad/fisiología , Deportes Acuáticos/fisiología , Atletas , Ergometría , Prueba de Esfuerzo , Femenino , Humanos , Consumo de Oxígeno/fisiología , Adulto Joven
5.
J Strength Cond Res ; 32(5): 1280-1287, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29373427

RESUMEN

Heishman, AD, Curtis, MA, Saliba, E, Hornett, RJ, Malin, SK, and Weltman, AL. Noninvasive assessment of internal and external player load: implications for optimizing athletic performance. J Strength Cond Res 32(5): 1280-1287, 2018-Few data exist that assess athlete tracking and monitoring for the development of strategies to optimize performance and reduce fatigue in elite athletes. The purpose of the present study was to assess the efficacy of external load and internal stress monitoring as assessment tools for examining a performance index of fatigue. A retrospective analysis was performed on data collected over the course of the preseason in 10 elite male NCAA Division 1 basketball players. Internal stress was assessed using Omegawave Technology readiness scores and compared with the performance index of countermovement jump (CMJ). The external load that accumulated during the previous practice, quantified by PlayerLoad (PL; Catapult), was compared with CMJ values and Omegawave scores. The results indicated that high, compared to low CNS Omegawave Readiness Scores (6.7 ± 05.1, 4.5 ± 1.2 AU; p < 0.001), were associated with increased CMJ (62.1 ± 6.5 vs. 59.4 ± 6.6 cm; p = 0.05), Power (6,590 ± 526.7 vs. 6,383.5 ± 606.8 W; p = 0.05), Omegawave Overall Readiness (5.8 ± 1.1 vs. 5.0 ± 0.7 AU; p = 0.05), and Omega Potential (Omega) (21.3 ± 6.3 vs. 9.9 ± 20.8 mV; p = 0.07). An increased PL during the previous exposure was associated with decreased CMJ (58.7 ± 4.7 cm vs. 60.4 ± 5.1 cm; p < 0.001) and increased TRIMP (135.1 ± 35.9 vs. 65.6 ± 20.0 AU; p < 0.001), and duration (115.4 ± 27.1 vs. 65.56 ± 20.0 minutes; p = < 0.001) despite no differences in Omegawave CNS Readiness scores. We conclude that Omegawave and Catapult technologies provide independent information related to performance and may be effective tools for monitoring athlete performance.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto/fisiología , Fatiga Muscular/fisiología , Atletas , Fatiga , Humanos , Masculino , Fuerza Muscular , Estudios Retrospectivos , Adulto Joven
6.
Res Sports Med ; 26(2): 178-190, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29361835

RESUMEN

Performance in soccer has been characterized previously using time-motion analyses; however, it is unclear if men's college soccer shares performance characteristics with women's college or men's professional soccer. The purpose of this study was to compare proportions of matches spent walking, jogging, running, and sprinting in men's college soccer. Twenty-two male college soccer players wore global positioning system units during matches. Proportions of walking, jogging, running, high-speed running, and sprinting were calculated for each player based on time period (first half, second half, extra time) and outcome (win, loss, tie). Multivariate analyses of variance were run for each time period to compare positions. Means, 95% confidence intervals, and effect sizes were calculated for each position based on time period and match outcome. There were differences in low-speed and high-speed activities based on position, with forwards and midfielders demonstrating increased high-speed activities. Positional differences may require different physiological profiles and should be a consideration during training.


Asunto(s)
Actigrafía , Trote , Carrera , Fútbol , Caminata , Adolescente , Sistemas de Información Geográfica , Humanos , Estudios Longitudinales , Masculino , Adulto Joven
7.
J Strength Cond Res ; 31(6): 1557-1562, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28538305

RESUMEN

Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto/fisiología , Ritmo Circadiano/fisiología , Fuerza Muscular/fisiología , Entrenamiento de Fuerza/métodos , Fatiga/fisiopatología , Humanos , Masculino , Estudios Retrospectivos , Sueño/fisiología , Factores de Tiempo , Universidades , Adulto Joven
8.
J Hepatol ; 62(1): 190-7, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25195547

RESUMEN

BACKGROUND & AIMS: This study's aim was to assess the histological and metabolic effects of n-3 polyunsaturated fatty acids (PUFAs) vs. placebo while adjusting for the impact of age and weight change in NASH patients. (ClinicalTrials.gov: NCT00681408). METHODS: Forty-one subjects with non-cirrhotic NASH were enrolled, and 34 completed the study. 17 received n-3 fish oil 3000 mg/day and 17 received placebo daily for 1 year with typical counselling on caloric intake and physical activity for all subjects. RESULTS: N-3- and placebo-treated groups showed no significant difference for the primary end point of NASH activity score (NAS) reduction ⩾ 2 points without fibrosis progression after adjustment for known covariates (n-3, 4/17 (23.5%); placebo, 3/17, (17.6%), p = 0.99). Among subjects with increased or stable weight, n-3 subjects showed a larger decrease in liver fat content by MRI than placebo-treated subjects (p = 0.014 for 2nd quartile, p = 0.003 for 3rd quartile of weight change). N-3 treatment showed significant fat reduction on the paired analysis of image-assisted fat morphometry regardless of weight loss or gain. Exercise capacity remained markedly reduced in all subjects. No independent effects on markers of hepatocyte injury or insulin sensitivity indices were observed. CONCLUSION: N-3 PUFAs at 3000 mg/day for one year did not lead to an improvement in the primary outcome of histological activity in NASH patients (⩾ 2 point NAS reduction). N-3 led to reduced liver fat by multiple measures. Other metabolic effects were not seen, although no detrimental effects were apparent. Whether longer duration, higher dose, or different composition of n-3 therapy would lead to additional benefits is uncertain.


Asunto(s)
Metabolismo Energético/efectos de los fármacos , Ácidos Grasos Omega-3/uso terapéutico , Hígado/patología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Adulto , Anciano , Biopsia , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Estudios Retrospectivos
10.
J Cardiovasc Magn Reson ; 15: 14, 2013 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-23343398

RESUMEN

BACKGROUND: The purpose was to determine the reproducibility and utility of rest, exercise, and perfusion reserve (PR) measures by contrast-enhanced (CE) calf perfusion magnetic resonance imaging (MRI) of the calf in normal subjects (NL) and patients with peripheral arterial disease (PAD). METHODS: Eleven PAD patients with claudication (ankle-brachial index 0.67 ±0.14) and 16 age-matched NL underwent symptom-limited CE-MRI using a pedal ergometer. Tissue perfusion and arterial input were measured at rest and peak exercise after injection of 0.1 mM/kg of gadolinium-diethylnetriamine pentaacetic acid (Gd-DTPA). Tissue function (TF) and arterial input function (AIF) measurements were made from the slope of time-intensity curves in muscle and artery, respectively, and normalized to proton density signal to correct for coil inhomogeneity. Perfusion index (PI) = TF/AIF. Perfusion reserve (PR) = exercise TF/ rest TF. Intraclass correlation coefficient (ICC) was calculated from 11 NL and 10 PAD with repeated MRI on a different day. RESULTS: Resting TF was low in NL and PAD (mean ± SD 0.25 ± 0.18 vs 0.35 ± 0.71, p = 0.59) but reproducible (ICC 0.76). Exercise TF was higher in NL than PAD (5.5 ± 3.2 vs. 3.4 ± 1.6, p = 0.04). Perfusion reserve was similar between groups and highly variable (28.6 ± 19.8 vs. 42.6 ± 41.0, p = 0.26). Exercise TF and PI were reproducible measures (ICC 0.63 and 0.60, respectively). CONCLUSION: Although rest measures are reproducible, they are quite low, do not distinguish NL from PAD, and lead to variability in perfusion reserve measures. Exercise TF and PI are the most reproducible MRI perfusion measures in PAD for use in clinical trials.


Asunto(s)
Prueba de Esfuerzo , Gadolinio DTPA , Extremidad Inferior/irrigación sanguínea , Imagen por Resonancia Magnética , Imagen de Perfusión/métodos , Enfermedad Arterial Periférica/diagnóstico , Radiofármacos , Anciano , Anciano de 80 o más Años , Índice Tobillo Braquial , Velocidad del Flujo Sanguíneo , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/fisiopatología , Valor Predictivo de las Pruebas , Flujo Sanguíneo Regional , Reproducibilidad de los Resultados , Factores de Tiempo
11.
J Appl Physiol (1985) ; 135(5): 1157-1166, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37823208

RESUMEN

Dietary nitrate (NO3-) is a widely used supplement purported to provide beneficial effects during exercise. Most studies to date include predominantly males. Therefore, the present study aimed to investigate if there is a sex-dependent effect of NO3- supplementation on exercise outcomes. We hypothesized that both sexes would exhibit improvements in exercise economy and exercise capacity following NO3- supplementation, but males would benefit to a greater extent. In a double-blind, randomized, crossover study, twelve females (24 ± 4 yr) and fourteen males (23 ± 4 yr) completed two 4-min moderate-intensity (MOD) exercise bouts followed by a time-to-exhaustion (TTE) task after following 3 days of NO3- supplementation (beetroot juice or BRJ) or NO3--depleted placebo (PL). Females were tested during the early follicular phase of the menstrual cycle. During MOD exercise, BRJ reduced the steady-state V̇o2 by ∼5% in males (M: Δ -87 ± 115 mL·min-1; P < 0.05) but not in females (F: Δ 6 ± 195 mL·min-1). Similarly, BRJ extended TTE by ∼15% in males (P < 0.05) but not in females. Dietary NO3- supplementation improved exercise economy during moderate-intensity exercise and exercise capacity during severe-intensity TTE in males but not in females. These differences could be related to estrogen levels, antioxidant capacity, nitrate-reducing bacteria, or a variety of known physiologic differences such as skeletal muscle calcium handling, and/or fiber type. Overall, our data suggests the ergogenic benefits of oral NO3- supplementation found in studies predominantly on male subjects may not be applicable to females.NEW & NOTEWORTHY While inorganic nitrate (NO3-) supplementation has increased in popularity as an ergogenic aid to improve exercise performance, the role of sex in NO3- supplementation on exercise outcomes is lacking despite known physiological differences during exercise between sex. This study revealed that males, but not females, improved exercise economy during submaximal exercise and exercise capacity during exercise within the severe-intensity domain following NO3- supplementation.


Asunto(s)
Beta vulgaris , Nitratos , Humanos , Masculino , Adulto Joven , Femenino , Caracteres Sexuales , Estudios Cruzados , Ejercicio Físico/fisiología , Suplementos Dietéticos , Antioxidantes , Método Doble Ciego , Consumo de Oxígeno/fisiología
12.
Vasc Med ; 17(1): 3-9, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22363013

RESUMEN

We hypothesized that percutaneous intervention in the affected lower extremity artery would improve calf muscle perfusion and cellular metabolism in patients with claudication and peripheral artery disease (PAD) as measured by magnetic resonance imaging (MRI) and spectroscopy (MRS). Ten patients with symptomatic PAD (mean ± SD: age 57 ± 9 years; ankle-brachial index (ABI) 0.62 ± 0.17; seven males) were studied 2 months before and 10 months after lower extremity percutaneous intervention. Calf muscle phosphocreatine recovery time constant (PCr) in the revascularized leg was measured by (31)P MRS immediately after symptom-limited exercise on a 1.5-T scanner. Calf muscle perfusion was measured using first-pass gadolinium-enhanced MRI at peak exercise. A 6-minute walk and treadmill test were performed. The PCr recovery time constant improved significantly following intervention (91 ± 33 s to 52 ± 34 s, p < 0.003). Rest ABI also improved (0.62 ± 0.17 to 0.93 ± 0.25, p < 0.003). There was no difference in MRI-measured tissue perfusion or exercise parameters, although the study was underpowered for these endpoints. In conclusion, in this pilot study, successful large vessel percutaneous intervention in patients with symptomatic claudication, results in improved ABI and calf muscle phosphocreatine recovery kinetics.


Asunto(s)
Pierna/irrigación sanguínea , Músculo Esquelético/irrigación sanguínea , Enfermedad Arterial Periférica/cirugía , Fosfocreatina/metabolismo , Procedimientos Quirúrgicos Vasculares/métodos , Adulto , Anciano , Anciano de 80 o más Años , Índice Tobillo Braquial , Ejercicio Físico/fisiología , Prueba de Esfuerzo , Femenino , Humanos , Claudicación Intermitente/cirugía , Angiografía por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Músculo Esquelético/metabolismo , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/metabolismo , Proyectos Piloto , Flujo Sanguíneo Regional
13.
J Strength Cond Res ; 26(8): 2043-50, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21986695

RESUMEN

This randomized, controlled, laboratory study was designed to examine the effect of cold water immersion (CWI) as a recovery modality on repeat performance on the yo-yo intermittent recovery test (YIRT), a widely accepted tool for the evaluation of physical performance in soccer, separated by 48 hours. Twenty-two healthy Division I collegiate soccer players (13 men and 9 women; age, 19.8 ± 1.1 years; height, 174.0 ± 9.0 cm; mass, 72.1 ± 9.1 kg) volunteered as participants during the noncompetitive season. The YIRT was used to induce volitional fatigue and was administered at baseline and again 48 hours later. Athletes progressively increased sprint speed between markers set 20 m apart until pace was failed. Countermovement vertical jump (CMVJ) was used to assess anaerobic power and was measured before YIRT, immediately post-YIRT, and 24 and 48 hours post-YIRT. A 10-cm horizontal visual analog scale was administered immediately, 24 hours and 48 hours post-YIRT to assess perceived fatigue (PF) in the legs. Participants were randomly placed into the CWI or control group. The CWI condition consisted of immersion to the umbilicus in a 12°C pool for 15 minutes, whereas the control group sat quietly for 15 minutes. There were no significant differences between intervention conditions on YIRT performance (control, 4,900 ± 884 m; CWI, 5,288 ± 1,000 m; p = 0.35) or PF (control, 9.4 ± 0.5 cm; CWI, 9.3 ± 0.6 cm; p = 0.65) at 48 hours post-YIRT. There was a main time effect for CMVJ over 48 hours, but no group differences (pre-YIRT, 64.6 ± 11.0 cm; post-YIRT, 66.4 ± 10.9 cm; 24 hours post-YIRT, 63.4 ± 9.9 cm; 48 hours post-YIRT, 63.1 ± 9.4 cm; p = 0.02). This study demonstrated that in collegiate soccer players, CWI performed immediately and 24 hours after induced volitional fatigue did not affect subsequent physical performance estimates.


Asunto(s)
Rendimiento Atlético/fisiología , Inmersión , Fútbol/fisiología , Adolescente , Prueba de Esfuerzo/métodos , Femenino , Humanos , Masculino , Fatiga Muscular/fisiología , Adulto Joven
14.
J Strength Cond Res ; 25(6): 1673-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21273909

RESUMEN

Throwing is a complex motion that involves the entire body and often puts an inordinate amount of stress on the shoulder and the arm. Warm-up prepares the body for work and can enhance performance. Sling-based exercise (SE) has been theorized to activate muscles, particularly the stabilizers, in a manner beneficial for preactivity warm-up, yet this hypothesis has not been tested. Our purpose was to determine if a warm-up using SE would increase throwing velocity and accuracy compared to a traditional, thrower's 10 warm-up program. Division I baseball players (nonpitchers) (16 men, age: 19.6 ± 1.3, height: 184.2 ± 6.2 cm, mass: 76.9 ± 19.2 kg) volunteered to participate in this crossover study. All subjects underwent both a warm-up routine using a traditional method (Thrower's 10 exercises) and a warm-up routine using closed kinetic chain SE methods (RedCord) on different days separated by 72 hours. Ball velocity and accuracy measures were obtained on 10 throws after either the traditional and SE warm-up regimens. Velocity was recorded using a standard Juggs radar gun (JUGS; Tualatin, OR, USA). Accuracy was recorded using a custom accuracy target. An Analysis of covariance was performed, with the number of throws recorded before the testing was used as a covariate and p < 0.05 was set a priori. There were no statistical differences between the SE warm-up and Thrower's 10 warm-up for throwing velocity (SE: 74.7 ± 7.5 mph, Thrower's 10: 74.6 ± 7.3 mph p = 0.874) or accuracy (SE: 115.6 ± 53.7 cm, Thrower's 10: 91.8 ± 55 cm, p = 0.136). Warming up with SE produced equivalent throwing velocity and accuracy compared to the Thrower's 10 warm-up method. Thus, SE provides an alternative to traditional warm-up.


Asunto(s)
Rendimiento Atlético/fisiología , Béisbol/fisiología , Ejercicio Físico/fisiología , Traumatismos en Atletas/prevención & control , Béisbol/lesiones , Codo/fisiopatología , Humanos , Masculino , Dolor/prevención & control , Hombro/fisiopatología , Muñeca/fisiopatología , Adulto Joven
15.
Clin Biomech (Bristol, Avon) ; 81: 105242, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33309931

RESUMEN

BACKGROUND: Individuals following anterior cruciate ligament reconstruction demonstrate quadriceps weakness throughout the post-operative recovery and at the time of returning to sport. This is often accompanied with patterns of quadriceps fatigue resistance. As such, fatigue may be an identifier of individuals with delayed recovery. The purpose was to assess quadriceps fatigue in anterior cruciate ligament reconstructed patients at the time of return to sport in comparison to healthy controls. METHODS: A total of 215 individuals, 120 following anterior cruciate ligament reconstruction (21.0 (2.9) years, 63 Female, 5.96 (0.48) months post-surgery) and 95 healthy controls (21.5 (8.4) years, 49 Female), participated in this study. All participants completed a 30-s knee extensor maximum voluntary isometric contraction. Knee extensor strength, limb symmetry index, and fatigue (%) were compared between groups. Between-limb fatigue comparisons were made through the Fatigue Index Limb Difference = [(Involved Limb Fatigue Index) - (Uninvolved Limb Fatigue Index)]. FINDINGS: Individuals following anterior cruciate ligament reconstruction (18.7 (10.9)%, -5.6 (11.2)) demonstrated lower values of unilateral fatigue and Fatigue Index Limb Difference compared to healthy participants (22.5 (8.2)%, P = .002; 2.2 (7.9), P < .001). For anterior cruciate ligament reconstructed patients, there was a weak, negative, significant relationship between the involved limb strength and fatigue (r = -0.184, P = .048). There was no relationship between limb symmetry and Fatigue Index Limb Difference (r = 0.137, P = .142). For Healthy individuals, there was a positive, moderate relationship between limb symmetry and Fatigue Index Limb Difference (r = 0.400, P < .001). INTERPRETATION: Individuals following anterior cruciate ligament reconstruction demonstrate fatigue resistance compared to healthy active controls and greater resistance to fatigue in their involved limb compared to their contralateral limb.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Rodilla/fisiología , Rodilla/cirugía , Fenómenos Mecánicos , Fatiga Muscular , Adulto , Distinciones y Premios , Fenómenos Biomecánicos , Femenino , Humanos , Contracción Isométrica , Masculino , Músculo Cuádriceps/fisiología , Adulto Joven
16.
JCO Oncol Pract ; 17(1): e16-e25, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32877271

RESUMEN

PURPOSE: This prospective trial's objective was to determine feasibility and outcomes of an exercise-based intervention for rural overweight/obese female cancer survivors. MATERIALS AND METHODS: Survivors of endometrial, breast, or ovarian cancer enrolled in a 6-month program of increased aerobic activity (30 minutes daily walking) and strength-training exercises using exercise bands (THERABAND; Akron, OH) with personalized telephone motivational coaching. Baseline demographics, anthropomorphic measurements, quality of life (QOL), fitness, and readiness to adopt exercise changes were assessed; daily steps, band use, and follow-up measurements were assessed at 3 and 6 months. Study completion was modeled using logistic regression. RESULTS: The mean age of the 99 women was 59.9 years, the mean body mass index (BMI) was 35.9 kg/m2, 88.9% were white, and 41.4% reported current exercise. Fifty-five women (55.6%) completed the 6-month program, and 36 (36.4%) completed exercise interventions. Using logistic regression to model study completion, only baseline QOL scores (physical component summary) and mental component summary) remained significant predictors. The mean weight change was a gain (0.88 kg). Higher MCS baseline scores and prior regular exercise predicted continued exercise and increased step counts, whereas higher BMI and baseline sleep predicted decreased QOL. Top walking barriers were feeling unwell and weather; barriers to strength exercises were band dislike and pain. CONCLUSION: The most significant predictor of trial completion and improved exercise outcomes was a higher baseline mental QOL. Motivation, belief in the importance of exercise, and prescribed/monitored exercise regimens were not sufficient; supportive and cognitive behavioral therapy interventions for survivors are needed to sustain uptake.


Asunto(s)
Supervivientes de Cáncer , Neoplasias , Ejercicio Físico , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Sobrevivientes
17.
Clin Biomech (Bristol, Avon) ; 71: 189-195, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31770661

RESUMEN

BACKGROUND: Osteoarthritis after anterior cruciate ligament reconstruction has been linked with changes in gait. Individuals with reconstruction demonstrate gait changes after exercise, however there is no information on altered gait after exercise based on sex. The purpose of this study was to examine the association of sex on changes in running gait after exercise in individuals with reconstruction compared to healthy. METHODS: Forty females (22 reconstructed) and 22 men (11 reconstructed) ran before and after exercise. Triplanar lower extremity kinematics and kinetics were measured on the involved limb. Data were reduced to 0-100% of gait. Change scores were calculated for each 1% with 90% confidence intervals. Mean differences were calculated for all significant differences. FINDINGS: After exercise, females with reconstruction increased knee valgus (1.81°), knee external rotation (2.02°), lateral trunk flexion (1.24°) and trunk rotation (2.15°) compared to healthy females. Females with reconstruction increased knee extension moment (0.07 Nm/kg), knee abduction moment (0.08 Nm/kg), hip extension moment (0.14 Nm/kg) and hip internal rotation moment (0.04 Nm/kg) compared to healthy females. After exercise, males with reconstruction decreased knee varus (-4.83°), hip adduction (-1.99°), and hip internal rotation (-4.44°), however increased lateral trunk flexion (1.94°) compared to healthy males. Males with reconstruction increased knee extension moment (0.07 Nm/kg), knee adduction moment (0.31 Nm/kg), knee internal rotation moment (0.13 Nm/kg), hip flexion moment (0.17 Nm/kg), and hip external rotation moment (0.05 Nm/kg) compared to healthy males. INTERPRETATION: Males with reconstruction increased hip loading while women with reconstruction increased trunk motion post-exercise. Sex should be considered when evaluating response to exercise after reconstruction.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior , Marcha , Articulación de la Rodilla/fisiología , Osteoartritis/complicaciones , Adulto , Fenómenos Biomecánicos , Ejercicio Físico , Femenino , Humanos , Masculino , Movimiento , Fuerza Muscular , Consumo de Oxígeno , Músculo Cuádriceps/fisiología , Rango del Movimiento Articular , Rotación , Carrera , Factores Sexuales
18.
Nutrients ; 11(8)2019 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-31434251

RESUMEN

In today's research environment, children's diet, physical activity, and other lifestyle factors are commonly studied in the context of health, independent of their effect on cognition and learning. Moreover, there is little overlap between the two literatures, although it is reasonable to expect that the lifestyle factors explored in the health-focused research are intertwined with cognition and learning processes. This thematic review provides an overview of knowledge connecting the selected lifestyle factors of diet, physical activity, and sleep hygiene to children's cognition and learning. Research from studies of diet and nutrition, physical activity and fitness, sleep, and broader influences of cultural and socioeconomic factors related to health and learning, were summarized to offer examples of research that integrate lifestyle factors and cognition with learning. The literature review demonstrates that the associations and causal relationships between these factors are vastly understudied. As a result, current knowledge on predictors of optimal cognition and learning is incomplete, and likely lacks understanding of many critical facts and relationships, their interactions, and the nature of their relationships, such as there being mediating or confounding factors that could provide important knowledge to increase the efficacy of learning-focused interventions. This review provides information focused on studies in children. Although basic research in cells or animal studies are available and indicate a number of possible physiological pathways, inclusion of those data would distract from the fact that there is a significant gap in knowledge on lifestyle factors and optimal learning in children. In a climate where childcare and school feeding policies are continuously discussed, this thematic review aims to provide an impulse for discussion and a call for more holistic approaches to support child development.


Asunto(s)
Cognición/fisiología , Función Ejecutiva/fisiología , Aprendizaje/fisiología , Estilo de Vida , Adolescente , Niño , Fenómenos Fisiológicos Nutricionales Infantiles , Preescolar , Cultura , Dieta , Ejercicio Físico/fisiología , Humanos , Lactante , Recién Nacido , Aptitud Física/fisiología , Sueño/fisiología , Factores Socioeconómicos , Estados Unidos
19.
Gait Posture ; 60: 35-40, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29153477

RESUMEN

Lower extremity injuries are most common in more active and fit individuals, suggesting that adaptations from neuromuscular fatigue may differ depending on type of exercise and fitness level. The purpose of this study was to compare changes in gait in highly fit and recreationally active individuals before and after two exercise protocols. Lower extremity kinematics and kinetics were measured on the dominant leg during running before and after two exercise protocols (walking/sport) from 0 to 100% of gait in 24 healthy individuals divided into higher (n=13) and lower fitness (n=11) groups. Change scores were calculated for each point of the gait cycle with 95% confidence intervals. There were no differences between groups in knee or hip kinematics and kinetics in response to the walking exercise protocol, however the higher fit group increased trunk extension and the lower fit group increased trunk lateral flexion after walking exercise. After the sport exercise, the higher fit group increased knee extension, knee valgus, trunk extension, knee flexion moment, knee varus moment, knee abduction moment, knee internal rotation moment, and hip flexion moment compared to the lower fit group. The lower fit group increased hip extension, hip abduction, hip internal rotation, trunk lateral flexion, trunk rotation, and knee external rotation moment compared the higher fit group after sport exercise. Greater between group differences were found with sport exercise compared to walking exercise. It is important to consider type of exercise and fitness level when assessing altered movement patterns in response to fatiguing exercise.


Asunto(s)
Ejercicio Físico/fisiología , Marcha/fisiología , Extremidad Inferior/fisiología , Aptitud Física/fisiología , Carrera/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Articulación de la Cadera/fisiología , Humanos , Articulación de la Rodilla/fisiología , Masculino , Movimiento/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Deportes/fisiología , Torso/fisiología , Caminata/fisiología , Adulto Joven
20.
Nutrition ; 34: 1-6, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28063503

RESUMEN

OBJECTIVE: The decline in insulin sensitivity (SI) associated with puberty increases the difficulty of achieving glycemic control in adolescents with type 1 diabetes (T1D). The aim of this study was to determine whether glutamine supplementation affects blood glucose by enhancing SI in adolescents with T1D. METHODS: Thirteen adolescents with T1D (HbA1C 8.2 ± 0.1%) were admitted to perform afternoon exercise (four 15-min treadmill/5-min rest cycles of exercise) on two occasions within a 4-wk period. They were randomized to receive a drink containing either glutamine (0.25 g/kg) or placebo before exercise, at bedtime, and early morning in a double-blind, crossover design. Blood glucose was monitored overnight, and a hyperinsulinemic-euglycemic clamp was performed the following morning. RESULTS: Blood glucose concentration dropped comparably during exercise on both days. However, the total number of nocturnal hypoglycemic events (17 versus 7, P = 0.045) and the cumulative probability of overnight hypoglycemia (50% versus 33%, P = 0.02) were higher on the glutamine day than on the placebo day. During clamp, glucose infusion rate was not affected by glutamine supplementation (7.7 ± 1 mg • kg-1 • min-1 versus 7.0 ± 1; glutamine versus placebo; P = 0.4). CONCLUSIONS: Oral glutamine supplementation decreases blood glucose in adolescents with T1D after exercise. Insulin sensitivity, however, was unaltered during the euglycemic clamp. Although the mechanisms involved remain to be elucidated, studies to explore the potential use of glutamine to improve blood glucose control are needed.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Ejercicio Físico , Glutamina/administración & dosificación , Resistencia a la Insulina , Adolescente , Glucemia/metabolismo , Índice de Masa Corporal , Estudios Cruzados , Suplementos Dietéticos , Método Doble Ciego , Ácidos Grasos no Esterificados/sangre , Femenino , Péptido 1 Similar al Glucagón/sangre , Técnica de Clampeo de la Glucosa , Humanos , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Insulina/sangre , Masculino
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