RESUMEN
Caffeine has documented hypoalgesic effects during exercise. However, there is a lack of research focusing on caffeine's potential analgesic effects to ameliorate delayed onset muscle soreness. A placebo controlled randomized cross-over trial was carried out to determine if 5 mg/kg of body weight (mg/kgBW) of caffeine attenuates muscle pain and improves 5 k running performance following delayed onset muscle soreness. Prior to participating, eleven runners (9 male; 2 female; age, 24.5 ± 6.3 years; height, 173.6 ± 7.8 cm; body mass, 66.3 ± 7.5 kg; BMI, 23.18 kg/m2 ± 1.6; VO2max 61.0 ± 6.1 ml/kg/min-1), were asked to discontinue supplement use for 72 hours and abstain from caffeine consumption for 48 hours. Participants performed a 30-minute downhill run on a treadmill set at -10% grade at 70% VO2max to induce delayed onset of muscle soreness. Participants then returned 48 hours after to complete a 5 k time trial run where they consumed either 5 mg/kgBW of caffeine or a placebo. Rate of perceived exertion and heart rate were taken every two minutes during the trial. There was no detectable statistical difference between 5 k performance between caffeine (1074.9 ± 119.7 sec) or placebo (1053.8 ± 86.8 sec) (p = .41). Algometer readings were similar between both treatments for muscle soreness in the rectus femoris (p = .791) and the vastus medialis oblique (p = .371). Muscle soreness ratings were found to be greater in the caffeine condition compared to the placebo condition (p = .030). There was no effect of treatment on rating of perceived exertion between conditions (p = .574). The present study suggests that caffeine is not effective at reducing muscle soreness, rating of perceived exertion, or improving running performance in a time trial in the presence of muscle soreness.
Asunto(s)
Cafeína , Carrera , Adolescente , Adulto , Analgésicos , Cafeína/farmacología , Método Doble Ciego , Femenino , Humanos , Masculino , Músculos , Mialgia/tratamiento farmacológico , Carrera/fisiología , Adulto JovenRESUMEN
The experiment examined the effects 4 weeks of vitamin D (Vit D) supplementation versus placebo on musculoskeletal and psychomotor performance. Thirty-two college age males (Age: 22 ± 4 y, Height: 177.7 ± 8.3 cm, Weight: 81.5 ± 14.6 kg, BF%: 19.6 ± 7.9, Vit D: 20.0 ± 7.2 ng/ml). Participants were assigned to group (Vit D vs placebo) and remained blind throughout the study. The treatments were 4000 IU of Vit D3 or placebo (dextrose) administered daily for 4 weeks. The participants underwent baseline testing for isometric strength, explosive ability and psychomotor performance, which was repeated at week 2 and week 4. Isometric tests consisted of an Isometric Mid Thigh Pull on a Force Plate (IMTP) and an upper body isometric test (UBIST) using a load cell. Peak force during a countermovement jump (CMJ) was also determined via force plate. A psychomotor vigilance test (PVT) was used to measure sustained reaction time. Analysis of the UBIST data did not reveal a significant group × time interaction (p = 0.14; Vit D pre: 553.7 ± 168.3 N, post: 585.5 ± 150.2 N; Placebo pre: 677.7 ± 182.3 N, post: 649.8 ± 236.9 N). For IMTP no significant group × time interaction (p = 0.83; Vit D pre: 2596.4 ± 342.3 N, post: 2606.9 ± 378.3 N; Placebo pre: 2684.0 ± 432.9 N, post: 2762.6 ± 440.4 N) was found. CMJ analysis did not reveal interaction effects for group × time (p = 0.21; Vit D pre: 4429.7 ± 1619.0 N, post: 4938.5 ± 2374.8 N; Placebo pre: 5537.3 ± 3027.0 N, post: 6266.9 ± 4577.3 N). For PVT (mean reaction time) there was no significant interaction effects for group × time (p = 0.35; Vit D pre: 0.304 ± 0.041 sec, post: 0.301 ± 0.053 sec; Placebo pre: 0.295 ± 0.044 sec, post: 0.284 ± 0.029 sec). In conclusion, four weeks of Vit D supplementation was not effective in increasing musculoskeletal or psychomotor performance.
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Colecalciferol , Desempeño Psicomotor , Adolescente , Adulto , Peso Corporal , Humanos , Masculino , Vitamina D , Vitaminas , Adulto JovenRESUMEN
Aim: To determine the effects of short-term Montmorency cherry (MC) supplementation upon exercise performance, total blood nitrate levels, muscle oxygenation, and slow-component [Formula: see text]O2 kinetics. Methods: Twelve healthy male participants ingested a MC or placebo (PL) supplement in a randomized cross-over fashion over a six day period then cycled at a power output achieved at 70% of [Formula: see text]O2 peak for a maximum of 30 minutes or until exhaustion. Near-Infrared Spectroscopy sensors were used to determine muscle oxygenation. Blood was collected one hour post-supplement consumption on day one, day six, and one hour post-exercise. Results: All results are presented as mean ± SEM. Blood nitrate (µM/L) levels were not different one hour post-ingestion (MC = 8.30 ± 2.15, PL = 8.18 ± 1.86), following six days of supplementation (MC = 9.14 ± 1.89, PL = 7.24 ± 1.75) or one hour post-exercise (MC = 9.63 ± 1.61, PL = 7.97 ± 1.92) for treatment F = 0.26, p = 0.62; for time F = 0.45, p = 0.64; or treatment by time interaction F = 2.28, p = 0.13. Muscle oxygenation was not different between treatments for the right or left vastus lateralis, F = 0.68, p = 0.81 nor was time to respiratory compensation point (minutes) (MC = 18.40 ± 1.48, PL = 17.16 ± 1.78) F = 0.52, p = 0.60. MC supplement ingestion does not alter blood nitrate levels. Conclusion: Short-term MC ingestion does not increase muscle oxygenation during cycling exercise nor does it change slow-component [Formula: see text]O2 kinetics.
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Suplementos Dietéticos , Músculo Esquelético , Estudios Cruzados , Método Doble Ciego , Ejercicio Físico , Humanos , MasculinoRESUMEN
Background and objectives: Striking a balance between maximizing performance and preventing injury remains elusive in many professional sports. The purpose of this study was to assess the relative risk of non-contact injuries in professional basketball players based on predictive cut scores on the Functional Movement Screen™ (FMS). Materials and Methods: Thirty-two professional basketball players from the National Basketball Association (NBA) and Women's National Basketball Association (WNBA) participated in this study. This observational pilot cohort study assessed and scored each participant using the FMS during training camp. Each athlete was then tracked throughout the season while recording the number, type, and time lost due to injuries. Possible exposures, actual exposures, and exposures missed due to non-contact injury (NCI) for each athlete were calculated and then used to determine the crude and specific incident rates for exposures missed due to NCI per 1000 exposures. Results: Linear regression models were used to evaluate the predictive ability of the FMS score for total missed exposures, NCI, and CI missed exposures. In all models, the FMS total score failed to attain significance as a predictor (p > 0.05). FMS scores ranged from 5 to 18. The recommended cut score of 14 showed a sensitivity of 0.474 and a specificity of 0.750. The cut score of 15 showed the best combination, exhibiting a sensitivity of 0.579 and specificity of 0.625. A total of 5784 exposures to NCI were possible for the men and women combined, and 681 possible exposures were missed. Of these, 23.5% were due to NCI, 16.5% were due to contact injuries (CI), and 60% were due to illnesses and personal reasons. Conclusions: The FMS proved to be a measure that was not associated with any injury measure in this sample of professional basketball players, suggesting the instrument lacks predictive validity in this population.
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Baloncesto , Atletas , Estudios de Cohortes , Femenino , Humanos , Masculino , Movimiento , Proyectos PilotoRESUMEN
Background and Objectives: National Collegiate Athletic Association (NCAA) soccer coaches implement numerous warm-up and flexibility strategies to prepare athletes for training and competition. The Fédération Internationale de Football Association (FIFA) developed the 11+ injury prevention program to reduce non-contact injuries. This study aimed to analyze the level of familiarity with and implementation of the evidence-based FIFA 11+ amongst NCAA Division I (DI) and Division III (DIII) men's and women's soccer coaches. Materials and Methods: NCAA soccer coaches in the United States received an Institutional Review Board-approved survey hyperlink. A total of 240 coaches completed the survey. The respondents represented 47.5% men's and 52.5% women's teams distributed within DI and DIII programs. Descriptive statistics are reported as frequency counts and mean ± standard deviation where applicable. Pearson's chi-square tests were performed to assess potential differences with a significance level set at α < 0.05. Results: The results indicated that approximately 62% of the respondents reported being familiar with the FIFA 11+ program. Of those coaches familiar with the program, 15.0% reported full implementation, 57.5% reported partial implementation, and 27.5% reported no implementation. Chi-square analyses revealed significant differences in FIFA 11+ implementation based upon division level (χ2 = 4.56, p = 0.033) and coaching certification levels (χ2 = 13.11, p = 0.011). Conclusions: This study indicates that there is a gap between FIFA 11+ knowledge and actual implementation. To reduce the risk of non-contact injury, there is a need to educate coaches and athletic trainers on the purpose of the FIFA 11+ program and how to perform the exercises correctly.
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Adhesión a Directriz , Guías como Asunto , Tutoría , Ejercicios de Estiramiento Muscular , Fútbol/fisiología , Ejercicio de Calentamiento , Traumatismos en Atletas/prevención & control , Certificación , Femenino , Humanos , Masculino , Tutoría/normas , Fútbol/clasificación , Fútbol/lesiones , Estados UnidosRESUMEN
It is important to identify potential underlying factors that can affect the variability of resting metabolic rate (RMR) measurements. The RMRs of 20 college-aged men were tested twice in stable environmental conditions, with each measurement separated by 40â¯min. Skin temperature, core temperature, and inter-beat interval were monitored throughout the study as identified factors that could affect RMR measurements. Since environmental conditions in a clinic or laboratory can vary, skin temperature and core temperature can be affected which may affect RMR. Similarly, prior physical activity, stress, sleep, and caffeine intake can affect inter-beat interval and may be a co-variable affecting RMR. Higher RMR measurements were compared to lower RMR measurements. RMR for the higher trial was 2068⯱â¯66â¯kcal/day, the lower trial was 1975⯱â¯65â¯kcal/day (tâ¯=â¯4.23; pâ¯<â¯0.01). Core temperature for higher trial was 37.1⯱â¯0.1⯰C, the lower trial was 36.8⯱â¯0.1⯰C (sâ¯=â¯105.00; pâ¯<â¯0.01). Skin temperature measurements were significantly different for the anterior bicep site (tâ¯=â¯-2.52; pâ¯=â¯0.02), but not for any other site. Inter-beat interval for the higher measurement was 1038⯱â¯33â¯ms, the lower measurement was 998⯱â¯32â¯ms (tâ¯=â¯3.82; pâ¯<â¯0.01). However, regression analysis found that none of the variables were significant predictors for the higher RMR, lower RMR, or change in RMR. While the factors affecting RMR measurement variability remain unclear, the results suggest that typical fluctuations in core temperature, skin temperature, and inter-beat interval do not effectively predict changes in RMR in a thermoneutral environment.
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Metabolismo Basal , Temperatura Corporal , Temperatura , Adulto , Calorimetría Indirecta , Frecuencia Cardíaca , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: Determining predictive markers for the development of type 2 diabetes (T2D), particularly in young individuals, offers immense potential benefits in preventative medicine. Previous research examining serum fibroblast growth factor 21 (FGF21) in humans has revealed equivocal relationships with clinical markers of metabolic dysfunction. However, it is unknown to what extent, if any, first-degree family history of T2D (mother or father of the participant diagnosed with T2D) level affects serum FGF21 levels. The aim of this study was to determine whether in healthy individuals with FH+ (n = 18) and without FH- (n = 17) a family history of T2D affects serum FGF21. MATERIALS AND METHODS: Fasting serum and clinical, metabolic and anthropometric measures were determined using a cross-sectional design. RESULTS: Differences between groups for FGF21 were not significant (FH+ = 266 pg/mL ± 51·4, FH = 180 pg/mL ± 29; Z = 0·97, P = 0·33). Adiponectin values were lower in FH+ (8·81 µg/mL ± 2·14) compared to FH- (10·65 µg/mL ± 1·44; F = 8·83, P = 0·01). Resistin was negatively correlated with FGF21 for all participants (r = -0·38, P = 0·03), but no other clinical, metabolic, or serum markers were predictive for serum FGF21 in FH+ or FH-. CONCLUSIONS: Serum FGF21 is not significantly different between FH+ and FH- in young, healthy individuals. Based upon the data of this pilot study, it is unclear whether serum FGF21 can be used as a stand-alone predictive marker for T2D in healthy subjects.
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Diabetes Mellitus Tipo 2/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Adiponectina/metabolismo , Adolescente , Adulto , Análisis de Varianza , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 2/sangre , Femenino , Voluntarios Sanos , Humanos , Masculino , Linaje , Adulto JovenRESUMEN
Popp, JK, Bellar, DM, Hoover, DL, Craig, BW, Leitzelar, BN, Wanless, EA, and Judge, LW. Pre- and post-activity stretching practices of collegiate athletic trainers in the United States. J Strength Cond Res 31(9): 2347-2354, 2017-The aim of the study was to investigate the knowledge and practices of collegiate-certified athletic trainers (ATs) in the United States. Participants (n = 521) were provided an overview of the study and a hyperlink to a web-based survey. The "pre- and post-activity practices in athletic training questionnaire" consisted of demographic items and elements to measure knowledge and practices related to pre- and post-activity stretching routines. In previous studies, the survey demonstrated construct validity, α = 0.722. Pearson chi-square test was used to evaluate goodness of fit, and kappa was calculated to measure agreement between items. Only 32.2% of ATs recommended dynamic stretching (DS) to be performed pre-activity, whereas a larger percentage (42.2%) recommended a combination of static stretching (SS) and DS. Athletic trainers reported that only 28.0% of athletes are performing DS before activity. Conversely, 60.6% of collegiate ATs recommended SS postexercise, and 61.0% of athletes agree and perform after workout SS (κ = 0.761, p < 0.001). Collegiate ATs seem to underuse the current research evidence, which indicates that DS is more beneficial than SS when used pre-activity, and ATs continue to regularly incorporate SS in their pre-activity routines. However, there is evidence that collegiate ATs in the United States emphasize SS postactivity in a manner consistent with current research.
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Atletas , Conocimientos, Actitudes y Práctica en Salud , Ejercicios de Estiramiento Muscular/métodos , Universidades , Adulto , Distribución de Chi-Cuadrado , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Deportes/educación , Estados UnidosRESUMEN
OBJECTIVE: The present study was conducted to assess the changes in mucosal immunity and pulmonary function among participants in a 36-hour mixed task ultraendurance race. METHODS: Thirteen of the 20 race participants volunteered for the investigation (age 34±5 y). The event consisted of a mixture of aerobic, strong man, and military-style exercise. Participants had a pulmonary function test and gave a finger stick capillary blood sample and unstimulated saliva samples both before the event and upon dropout or completion. The blood sample was analyzed for hematocrit, and the saliva sample was analyzed for salivary flow rate, salivary alpha amylase, salivary immunoglobulin A (IgA), and IgA type 1. RESULTS: Significant differences were noted among the finishers and those who dropped out in salivary flow rate (P = .026), salivary IgA (P = .017), and peak expiratory flow (P = .05) measurements. Salivary flow rate and IgA for the race finishers were reduced from pre- to postrace, whereas the nonfinishers showed no change or small increases. No significant differences emerged for other variables. CONCLUSIONS: Based on the results of the present investigation, finishing a 36-hour mixed task ultra-endurance event results in a decline in both pulmonary function and mucosal immunity compared with competitors who do not finish.
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Biomarcadores/análisis , Inmunidad Mucosa , Resistencia Física , Pruebas de Función Respiratoria , Adulto , Biomarcadores/metabolismo , Femenino , Hematócrito , Humanos , Inmunoglobulina A/metabolismo , Masculino , Saliva/metabolismo , Evaluación de Capacidad de Trabajo , alfa-Amilasas/metabolismoRESUMEN
The purpose of the study was to examine the effects of acute androstenedione supplementation on hormone levels in older men at rest and during exercise. Men (n = 11) between the ages of 58 and 69 were divided into an experimental (n = 6; 62.33 ± 2.57 y) and control (n = 5; 60.2 ± 1.02 y) groups. Each participant received an oral 300 mg dose of either androstenedione (experimental) or a cellulose placebo (control) for 7 d. Pre- and post-supplementation participants completed two separate, 20-min strength tasks consisting of leg extension and leg curls at different percentages of their 10-RM. Researchers collected blood samples pre-, during, and post-exercise. Blood samples were analyzed for testosterone, androstenedione, and estradiol levels. The researchers found a significant difference between pre- (4.36 ± 56 ng/mL) and post- (5.51 ± 0.35 ng/mL) testosterone levels, as well as pre- (0.88 ± 0.20) and post- (7.46 ± 1.25) androstenedione levels, but no significant differences between pre- and post-estradiol levels for either group. It appears that short-term androstenedione supplementation augmented acute testosterone responses to resistance exercise in older men. However, further study of this supplement is needed to determine any potential it may have in mitigating andropause.
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Androstenodiona/uso terapéutico , Suplementos Dietéticos , Testosterona/sangre , Anciano , Androstenodiona/administración & dosificación , Ejercicio Físico/fisiología , Humanos , Masculino , Persona de Mediana Edad , Testosterona/deficienciaRESUMEN
The purpose of this investigation was to determine the acute effects of heavy and light implements on subsequent overhead back (OHB) shot put performance with a competition weight shot put. This investigation was designed to test the efficacy of heavy implements for potentiating subsequent OHB performance. Participants included 41 athletes (20.9 ± 1.18 years.) from 2 National Collegiate Athletic Association Division I schools in the Midwestern United States (n = 23 male and n = 18 female). Mean distance for OHB throw with a competition shot put was examined after treatment (control, light shot put warm-up, and heavy shot put warm-up) through repeated-measures analysis of variance (ANOVA) with post hoc Bonferroni-corrected post hoc analysis. Responses after treatment on the 10-cm visual analog scale (VAS) fatigue were examined through repeated-measures ANOVA and demonstrated a significant main effect for treatment on VAS fatigue (F = 16.463; p = 0.001). The heavy shot put warm-up resulted in the greatest mean performance over the course of the 3 attempts (14.39 ± 1.82 m) followed by the light shot put warm-up (14.18 ± 1.68 m) and the control (14.15 ± 1.70 m). Results of the repeated-measures ANOVA demonstrated a significant main effect for treatment in regard to average distance (F = 6.276; p = 0.003). Post hoc testing suggested that the heavy shot put warm-up resulted in significantly better mean OHB performance than either the light shot put warm-up (t = 2.983; p = 0.0048; ES = 0.472; power = 0.901) or the control shot put warm-up (t = 3.349; p = 0.0018; effect size [ES] = 0.513; power = 0.939). Subsequent analysis examined the relationship between reported fatigue accrued during the overweight shot put warm-up and the change in performance on the OHB throw when compared to the control condition. Analysis revealed that subjects who reported higher levels of VAS fatigue did not perform as well after the overweight treatment (p = 0.0274).
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Rendimiento Atlético/fisiología , Músculo Esquelético/fisiología , Acondicionamiento Físico Humano/métodos , Adolescente , Adulto , Femenino , Humanos , Masculino , Fatiga Muscular/fisiología , Escala Visual Analógica , Adulto JovenRESUMEN
Judge, LW, Kumley, RF, Bellar, DM, Pike, KL, Pierson, EE, Weidner, T, Pearson, D, and Friesen, CA. Hydration and fluid replacement knowledge, attitudes, barriers, and behaviors of NCAA Division 1 American football players. J Strength Cond Res 30(11): 2972-2978, 2016-Hydration is an important part of athletic performance, and understanding athletes' hydration knowledge, attitudes, barriers, and behaviors is critical for sport practitioners. The aim of this study was to assess National Collegiate Athletic Association (NCAA) Division 1 (D1) American football players, with regard to hydration and fluid intake before, during, and after exercise, and to apply this assessment to their overall hydration practice. The sample consisted of 100 student-athletes from 2 different NCAA D1 universities, who participated in voluntary summer football conditioning. Participants completed a survey to identify the fluid and hydration knowledge, attitudes and behaviors, demographic data, primary football position, previous nutrition education, and barriers to adequate fluid consumption. The average Hydration Knowledge Score (HKS) for the participants in the present study was 11.8 ± 1.9 (69.4% correct), with scores ranging from 42 to 100% correct. Four key misunderstandings regarding hydration, specifically related to intervals of hydration habits among the study subjects, were revealed. Only 24% of the players reported drinking enough fluids before, during, immediately after, and 2 hours after practice. Generalized linear model analysis predicted the outcome variable HKS (χ = 28.001, p = 0.045), with nutrition education (Wald χ = 8.250, p = 0.041) and position on the football team (χ = 9.361, p = 0.025) being significant predictors. "Backs" (e.g., quarterbacks, running backs, and defensive backs) demonstrated significantly higher hydration knowledge than "Linemen" (p = 0.014). Findings indicated that if changes are not made to increase hydration awareness levels among football teams, serious health consequences, including potential fatalities, could occur on the field, especially among heavier linemen.
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Atletas/psicología , Conducta de Ingestión de Líquido , Ingestión de Líquidos , Fútbol Americano/psicología , Conocimientos, Actitudes y Práctica en Salud , Adolescente , Rendimiento Atlético , Humanos , Masculino , Estudiantes , Encuestas y Cuestionarios , Estados Unidos , Universidades/organización & administración , Adulto JovenRESUMEN
Judge, LW, Urbina, LJ, Hoover, DL, Craig, BW, Judge, LM, Leitzelar, BM, Pearson, DR, Holtzclaw, KA, and Bellar, DM. The impact of competitive trait anxiety on collegiate powerlifting performance. J Strength Cond Res 30(9): 2399-2405, 2016-The purpose of this study was to determine the relationship between competitive trait anxiety measures and powerlifting (PL) performance. Thirty-six collegiate powerlifters on club teams from 3 universities were recruited during a competition (men = 26, women = 10; age = 19.9 ± 1.5 years; height = 172.5 ± 8.6 cm; weight = 81.4 ± 21.0 kg). The athletes were distributed across weight classes for collegiate PL (47.6 kg: 1; 51.7 kg: 1; 54.9 kg: 1; 59.8 kg: 3; 67.1 kg: 2; 74.8 kg: 7; 82.1 kg: 4; 89.8 kg: 9; 99.8 kg: 5; super heavyweight: 3). A survey containing questions about PL performance history and the 15-item Sport Competition Anxiety Test (SCAT) were administered to the participants before competing. The SCAT total was negatively correlated (r = -0.397; p = 0.02) to the athletes' percentage of best total achieved in the competition (actual performance total/best comp total × 100). Of the individual lifts, the SCAT score was negatively correlated to the personal best for bench press (r = -0.368; p = 0.03) and deadlift (r = -0.317, p = 0.05), but did not significantly correlate for squat (r = -0.182, p = 0.27). These results indicate a negative correlation between the SCAT score and athletes' personal best totals in PL. Increased SCAT scores were associated with decreased personal best PL totals. The results suggest that competitive trait anxiety may have negatively impacted performance and that some PL athletes may benefit from interventions aimed at decreasing anxiety before and during performance.
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Ansiedad/psicología , Rendimiento Atlético/psicología , Levantamiento de Peso/psicología , Adolescente , Adulto , Peso Corporal , Femenino , Humanos , Masculino , Deportes , Encuestas y Cuestionarios , Universidades , Adulto JovenRESUMEN
The ability to use data from tests of maximum aerobic capacity to estimate the ventilatory threshold and point of respiratory compensation (RCP) is useful for coaches and practitioners in the development of training schemes. Current methods for determining the RCP generally involve identifying deflections in respiratory variables when examined alongside minute ventilation. This investigation describes a novel mathematical method for determining RCP using standard scores (Z-scores) for minute ventilation (VE) and oxygen consumption (VO2). This method allows for the point where ventilation becomes disproportionate to oxygen consumption to be quantified as an intersection between 2 lines of best fit. This novel Z-score method was compared with a well-described determination of RCP and was found to be highly correlated (r = 0.926, p ≤ 0.001). The Z-score method was also found to be related to 10-km road race performance using regression analysis (R(2) = 0.824, p ≤ 0.001) in a group of 18 athletes and recreational runners. Based on the evidence from this study, the Z-score method of RCP determination is highly correlated to previous methods and endurance performance. This method potentially offers further benefits as it is not reliant on visual determination of changes in slope in variables of interest but rather on the mathematical solution to the intersection of 2 regression lines.
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Umbral Anaerobio , Conceptos Matemáticos , Ventilación Pulmonar , Fenómenos Fisiológicos Respiratorios , Adolescente , Adulto , Rendimiento Atlético/fisiología , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Carrera/fisiología , Adulto JovenRESUMEN
The purpose of this study was to analyze the level of creatine use along with the perceived benefits and barriers of creatine use among collegiate athletes who participate in throwing events within the sport of track and field. A total of 258 throwers from National Collegiate Athletic Association Division I institutions completed an online survey regarding creatine. The results provided baseline levels of creatine use and allowed for the analysis of factors related to athletic conference affiliation. Results indicate that creatine use remains to be a common (32.7%) practice among throwers with significantly higher levels of use among Football Bowl Subdivision (FBS) conference athletes (44.6%) than Football Championship Subdivision (FCS) conference athletes (28.8%), χ² = 5.505, p = 0.019. The most common reasons for using creatine included a desire to improve/increase: strength (83.3%), recovery time (69.0%), and performance (60.7%). The most common perceived obstacles included contamination/quality control (39.5%), cost (33.3%), inconvenience (16.7%), and cramping (14.3%). A desire for additional education and training was noted through an expression of interest (55.6%) with significantly higher levels of interest from FBS athletes (65.6%) than FCS athletes (52.2%), χ² = 6.425, p = 0.039. However, the athletic departments provide nutritional supplement counseling at only 26.6% of the schools. Although the access to full-time nutritionist counsel was available at 57.3% of the schools, there was a significant difference (χ² = 9.096, p = 0.003) between FBS schools (73.7%) and FCS schools (51.7%).
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Información de Salud al Consumidor , Creatina , Suplementos Dietéticos , Utilización de Medicamentos/estadística & datos numéricos , Sustancias para Mejorar el Rendimiento , Atletismo/estadística & datos numéricos , Adolescente , Creatina/efectos adversos , Suplementos Dietéticos/efectos adversos , Femenino , Humanos , Masculino , Sustancias para Mejorar el Rendimiento/efectos adversos , Encuestas y Cuestionarios , Estados Unidos , Universidades , Adulto JovenRESUMEN
Childhood obesity affects 1 of every 6 youth in the United States. One contributing factor to this statistic is a lack of physical activity (PA). Demands related to accountability which are placed on educators to demonstrate academic achievement often result in resistance to allocating time during the school day for PA. One possible solution is to consider utilizing time after school to integrate PA programs. The purpose of this study was to assess the impact of a 12-week after-school pedometer-focused PA program on aerobic capacity and to examine the relationship between step count and aerobic capacity in elementary school aged children. A group of elementary students (n = 24; 9.5 ± 0.9 years) participated in a 12-week pedometer-focused PA program that included pretraining and posttraining fitness testing via the 20-meter version of the PACER test. Paired sample t-tests revealed significant differences between the pretest (M = 21.0 laps, SD = 9.9) and posttest (M = 25.2 laps, SD = 12.2) scores (t = 4.04, P ≤ 0.001). A Pearson correlation revealed no significant relationship between individual step count and the difference between PACER pre- and posttest (r = 0.318, P = 0.130). The program improved aerobic capacity, but an increase in pedometer-calculated step count was not a predictor.
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Actigrafía/métodos , Tolerancia al Ejercicio/fisiología , Consumo de Oxígeno/fisiología , Acondicionamiento Físico Humano/métodos , Aptitud Física/fisiología , Carrera/fisiología , Servicios de Salud Escolar , Niño , Prueba de Esfuerzo/métodos , Femenino , Humanos , Masculino , Monitoreo Ambulatorio/métodos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The purpose of this investigation was to examine the effects of a personal oxygen supplement (OS) on performance during exhaustive exercise, respiratory responses during exhaustive exercise, and cognitive function after exhaustive exercise. The participants for this blind placebo-controlled experiment were apparently healthy college-aged adults (n = 20). First, VO2max was assessed (47.6 ± 9.8 ml O2·kg(-1)·min(-1)). Participants then ran 2 trials at 80% of VO2max speed to exhaustion and received either a placebo (compressed air) or personal OS. Psychomotor vigilance testing (PVT) was performed before and after each trial. Performance between treatments was evaluated through repeated measures analysis of variance (ANOVA) and was not found to be different (p = 0.335, ηp2 = 0.052), and order (placebo first or personal OS first) was not significant within the model (p = 0.305, ηp2 = 0.058). Mean times were 1,057.6 ± 619.8 seconds for the oxygen trials and 992.5 ± 463.1 seconds for the placebo trials. Repeated measures ANOVAs were used to assess minute ventilation (Ve, L·min(-1)) and VCO2 (L·O2·min(-1)) during exercise and recovery, mean heart rate during recovery, and PVT results. Treatment was nonsignificant (p > 0.05) nor were any interaction effects (treatment × time, p > 0.05) for any variables. The results of this study suggest that a personal OS had no effect on performance and did not affect ventilation even at the time directly surrounding the application. The results of the study also suggest that personal OS do not enhance exercise recovery or cognition during exercise recovery.
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Rendimiento Atlético/fisiología , Cognición/fisiología , Fatiga/fisiopatología , Oxígeno/administración & dosificación , Resistencia Física/fisiología , Adulto , Femenino , Frecuencia Cardíaca , Humanos , Pierna , Masculino , Mialgia , Consumo de Oxígeno , Esfuerzo Físico , Desempeño Psicomotor/fisiología , Ventilación Pulmonar , Carrera/fisiología , Método Simple Ciego , Adulto JovenRESUMEN
Strength and conditioning training programs are essential components of athletic performance, and the effectiveness of these programs can be linked to the strength and conditioning facilities (SCFs) used by athletes. The primary purpose of this study was to provide a statistical overview of National Collegiate Athletic Association (NCAA) Division I SCFs, equipment and maintenance budget, and the relationship between SCF budget and staffing space, and equipment. The secondary purpose was to note differences in SCFs between those schools with and without football programs. An 84-item online survey instrument, developed with expert input from certified strength professionals, was used to collect data regarding the SCFs in NCAA Division I universities. A total of 110 valid and complete surveys were returned for a response rate of 38.6%. Results of Pearson's χ2 analysis demonstrated that the larger reported annual equipment budgets were associated with larger SCFs (χ2 = 451.4, p ≤ 0.001), greater maximum safe capacity of athletes using the facility (χ2 = 366.9, p ≤ 0.001), increased numbers of full-time coaches (χ2 = 224.2, p ≤ 0.001), and increased number of graduate assistant or intern coaches (χ2 = 102.9, p ≤ 0.001). Based on these data, it can be suggested to athletic administrators and strength and conditioning professionals at the collegiate level that budgets need to be re-evaluated as the number of personnel available to monitor student-athletes and the size and safe capacity of the facility are related to the ability of the strength and conditioning staff to safely and adequately perform their duties.
Asunto(s)
Centros de Acondicionamiento , Fútbol Americano , Acondicionamiento Físico Humano , Entrenamiento de Fuerza , Equipo Deportivo , Universidades , Centros de Acondicionamiento/economía , Centros de Acondicionamiento/estadística & datos numéricos , Fútbol Americano/clasificación , Fútbol Americano/economía , Fútbol Americano/estadística & datos numéricos , Humanos , Diseño Interior y Mobiliario/economía , Acondicionamiento Físico Humano/economía , Acondicionamiento Físico Humano/instrumentación , Entrenamiento de Fuerza/instrumentación , Equipo Deportivo/economía , Equipo Deportivo/estadística & datos numéricos , Estados Unidos , Universidades/clasificación , Universidades/economía , Universidades/estadística & datos numéricos , Recursos HumanosRESUMEN
There are many tests available to coaches and practitioners who seek to identify a point during exercise when excess lactate is being produced or hyperventilation stimulated as a result of metabolic acidosis. This investigation sought to determine the relationship between performance and the first occurrence of excess CO2 production because of increased ventilatory buffering. For this investigation, 2 separate studies were conducted, each examined the predictive value of the 2 standard ventilatory threshold (VT) assessments (V-Slope and examination of ventilatory equilvalents) and the point of equivalence in change (PEC) against performance in an endurance race. The PEC was determined by examining the third-order trend for V[Combining Dot Above]CO2 and V[Combining Dot Above]O2 and determining where the change by time was equivalent (ΔV[Combining Dot Above]O2/ΔV[Combining Dot Above]O2 = 1). The first study examined the assessments of PEC vs. VT in a population of 10-km race competitors (study 1) and the second a population of National Collegiate Athletic Association Division 1 crosscountry runners (study 2). Partial correlations (controlled for weight) were used to assess the relationships with performance. In study 1, the partial correlations revealed that the PEC had the highest correlation to race performance (r = 0.961, p < 0.001) compared with the other techniques (V-slope r = 0.890, p < 0.001, ventilatory equivalents r = 0.733, p = 0.01). Analyses of difference in strength of correlations within study 1 demonstrated differences between PEC and mean race speed as compared with V-slope or ventilatory equivalents and mean race speed. In study 2, a similar trend was observed (PEC r = 0.863, p = 0.001, V-slope (r = 0.828, p = 0.002, ventilatory equivalents r = 0.750, p = 0.008). The results of this study suggest that determination of PEC is more related to 10-km race performance than 2 well-established methods for VT determination.
Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Resistencia Física/fisiología , Ventilación Pulmonar/fisiología , Carrera/fisiología , Umbral Anaerobio/fisiología , Femenino , Humanos , Louisiana , Masculino , Modelos Biológicos , Consumo de Oxígeno , Educación y Entrenamiento Físico , Valor Predictivo de las Pruebas , Análisis de Regresión , Adulto JovenRESUMEN
The rapid growth and expanding use of high school strength and conditioning facilities (SCFs) creates a need to research and better understand these vital facilities. This study was designed to examine SCFs at the high school level including facility size, equipment, leadership/staffing, and safety. A 70-item online survey instrument, developed with expert input from certified strength professionals, was used to collect data regarding the SCFs in high schools throughout a midwestern state, and was distributed via email to a total of 390 high school athletic directors. Survey respondents (n = 108) all reported the presence of SCFs with 95.4% indicating a dedicated SCF space. A strong positive correlation (r = 0.610, p ≤ 0.001) was determined between the variables of SCF size in square feet and school size measured by total enrollment. Analysis of variance and χ² analyses revealed significant differences in equipment, facility size, and safety factors based on the categorical variables of school size and the presence of certified strength and conditioning specialist (CSCS) leadership. It appears the CSCS's application of their scientific knowledge goes beyond training athletes for the goal of improving athletic performance to actually influence the SCF itself. Athletic administrators at the high school level need to recognize the impact CSCS program leadership can have on the overall quality of the strength and conditioning program and facility.