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1.
J Strength Cond Res ; 38(5): 948-950, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38662886

RESUMEN

ABSTRACT: Peveler, WW, Schoffstall, J, Coots, J, Kilian, J, and Glauser, J. The effects of boxing glove design on thumb position when making a fist for striking. J Strength Cond Res 38(5): 948-950, 2024-It has been suggested that boxing glove design alters thumb position increasing the risk of injury. The purpose of this study was to determine the effects of boxing glove design on thumb joint angles when making a fist. Ten experienced fighters participated in this study. A DEXA scan was used to produce an x-ray image of thumb position for all conditions (no gloves and 10-oz boxing gloves). Mean values for dependent measures were compared using a paired-sample T test and an alpha of 0.05. The carpometacarpal (CMC) joint angle was significantly different between no glove (14.1 ± 6.54°) and boxing glove (34.2 ± 7.60°) at p ≤ 0.001. The metacarpophalangeal (MP) joint angle was significantly different between no glove (132.6 ± 12.74°) and boxing glove (149.40 ± 8.15°) at p ≤ 0.001. The IP joint angle was not significantly different between no glove (135.50 ± 19.12°) and boxing glove (144.40 ± 17.39°) at p = 0.269. The perpendicular distance from the second metacarpal of the hand to the center of the MP joint was significantly different between no glove (0.48 ± 0.54 cm) and boxing glove (1.84 ± 0.29 cm) at p ≤ 0.001. Use of a boxing glove resulted in abduction of the thumb away from the hand and increased CMC and MP joint angles that were significantly different in relation to making a fist without a glove. Information from this study may provide insight into the high rate of thumb injury and provide insight for future boxing glove design.


Asunto(s)
Diseño de Equipo , Pulgar , Humanos , Pulgar/fisiología , Adulto , Masculino , Boxeo/fisiología , Articulación Metacarpofalángica/fisiología , Articulaciones Carpometacarpianas , Adulto Joven , Guantes Protectores
2.
Int J Exerc Sci ; 10(4): 640-648, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28674606

RESUMEN

Performance threshold measures are used to predict cycling performance. Previous research has focused on long time trials (≥ 40 km) using power at ventilatory threshold and respiratory threshold to estimate time trial performance. As intensity greatly differs during shorter time trails applying findings from longer time trials may not be appropriate. The use of heart rate measures to determine 20 km time trial performance has yet to be examined. The purpose of this study was to determine the effectiveness of heart rate measures at ventilatory threshold (VE/VO2 Plotted and VT determined by software) and respiratory threshold (RER of 0.95, 1.00, and 1.05) to predict 20 km time trial performance. Eighteen cyclists completed a VO2max protocol and two 20 km time trials. Average heart rates from 20 km time trials were compared with heart rates from performance threshold measures (VT plotted, VT software, and an RER at 0.95, 1.00, and 1.05) using repeated measures ANOVA. Significance was set a priori at P ≤ 0.05. The only measure not found to be significantly different in relation to time trial performance was HR at an RER of 1.00 (166.61±12.70 bpm vs. 165.89 ± 9.56 bpm, p = .671). VT plotting and VT determined by software were found to underestimate time trial performance by 3% and 8% respectively. From these findings it is recommended to use heart rate at a RER of 1.00 in order to determine 20 km time trial intensity.

3.
J Strength Cond Res ; 31(4): 882-887, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27386963

RESUMEN

Peveler, WW, Sanders, GJ, Marczinski, CA, and Holmer, B. Effects of energy drinks on economy and cardiovascular measures. J Strength Cond Res 31(4): 882-887, 2017-The use of energy drinks among athletes has risen greatly. Caffeine and taurine are the 2 primary performance enhancing ingredients found in energy drinks. The number of emergency department visits involving energy drinks doubled over the past 5 years. Reviews of the health complications have highlighted adverse cardiovascular events. The literature reveals that caffeine is known to moderately increase blood pressure (BP) and heart rate (HR). The purpose of this study was to determine the effect of 3 different energy drinks on cardiovascular and performance measures. Fifteen recreational runners completed 5 trials. The first trial consisted of a graded exercise protocol. The 4 remaining trials consisted of 15-minute economy trials at a treadmill speed consistent with 70% of subject's V[Combining Dot Above]O2max. An hour before subjects ingested 1 of the 3 energy drinks or a placebo. HR, BP, V[Combining Dot Above]O2, and rating of perceived exertion (RPE) were recorded during the 15-minute trial. Mean values for dependent measures were compared using repeated-measures analysis of variance. Fifteen-minute systolic BP readings were significantly lower in the placebo trials (156.93 ± 15.50) in relation to the 3 energy drink trials (163.87 ± 13.30, 166.47 ± 13.71, and 165.00 ± 15.23). There were no significant differences in diastolic BP and HR. There were no significant differences found in V[Combining Dot Above]O2 or RPE measures. Ingestion of energy drinks demonstrated no change in V[Combining Dot Above]O2 or RPE during the economy trials. The findings show no performance benefits under the conditions of this study. However, there does appear to be a significant increase in systolic BP.


Asunto(s)
Cafeína/farmacología , Bebidas Energéticas , Carrera/fisiología , Taurina/farmacología , Adolescente , Adulto , Atletas , Presión Sanguínea/efectos de los fármacos , Ejercicio Físico/fisiología , Prueba de Esfuerzo/métodos , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Consumo de Oxígeno/efectos de los fármacos , Esfuerzo Físico/efectos de los fármacos , Adulto Joven
4.
J Strength Cond Res ; 27(10): 2823-7, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23287833

RESUMEN

The CompuTrainer is commonly used to measure cycling time trial performance in a laboratory setting. Previous research has demonstrated that the CompuTrainer tends toward underestimating power at higher workloads but provides reliable measures. The extent to which the CompuTrainer is capable of simulating outdoor time trials in a laboratory setting has yet to be examined. The purpose of this study was to examine the validity of replicating an outdoor time trial course indoors by comparing completion times between the actual time trial course and the replicated outdoor time trial course on the CompuTrainer. A global positioning system was used to collect data points along a local outdoor time trial course. Data were then downloaded and converted into a time trial course for the CompuTrainer. Eleven recreational to highly trained cyclists participated in this study. To participate in this study, subjects had to have completed a minimum of 2 of the local Cleves time trial races. Subjects completed 2 simulated indoor time trials on the CompuTrainer. Mean finishing times for the mean indoor performance trial (34.58 ± 8.63 minutes) were significantly slower in relation to the mean outdoor performance time (26.24 ± 3.23 minutes). Cyclists' finish times increased (performance decreased) by 24% on the indoor time trials in relation to the mean outdoor times. There were no significant differences between CompuTrainer trial 1 (34.77 ± 8.54 minutes) and CompuTrainer trial 1 (34.37 ± 8.76 minutes). Because of the significant differences in times between the indoor and outdoor time trials, meaningful comparisons of performance times cannot be made between the two. However, there were no significant differences found between the 2 CompuTrainer trials, and therefore the CompuTrainer can still be recommended for laboratory testing between trials.


Asunto(s)
Rendimiento Atlético/fisiología , Ciclismo/fisiología , Ergometría/instrumentación , Sistemas de Información Geográfica , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo
5.
J Strength Cond Res ; 26(4): 1149-53, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22398820

RESUMEN

Manufacturers of supplements containing magnesium lactate dihydrate and calcium lactate monohydrate claim improved athletic performance. Although energy can be produced through the lactate shuttle system, there is limited evidence to suggest that substantial quantities are available for human movement during exercise. The purpose of this study was to evaluate the effectiveness of lactate as a performance-enhancing substance. Nine recreational to competitive cyclists (VO2max = 52.46 ± 11.8) completed 3 simulated 20-km time trials conducted on a Velotron. The first trial was used as a familiarization trial, and the last 2 trials were counterbalanced ergogenic aid/placebo trials. To eliminate the possibility of bias, the study was conducted double blind. Dependent measures (time, mean power, heart rate [HR], and ratings of perceived exertion) for the 3 trials were compared using repeated measures analysis of variance (p = 0.05). There were no significant differences between placebo and ergogenic aid in measures of time (38.78 ± 5.87 minutes vs. 39.07 ± 6.00 minutes; p = 0.212), mean power (236.40 ± 74.8 W vs. 232.81 ± 76.12 W; p = 0.342), and HR (167.36 ± 10.11 minutes vs. 163.70 ± 13.07 minutes; p = 0.092). Ratings of perceived exertion for the placebo trial were significantly higher in relation to the ergogenic aid trial (15.97 ± 0.72 vs. 15.70 ± 0.85; p = 0.039). Although not significant, times during the placebo trials were faster in relation to the ergogenic aid trials. Ratings of perceived exertion were significantly higher in the placebo trials, which could reflect the trend toward faster times. Supplementation of magnesium lactate dihydrate and calcium lactate monohydrate does not appear to significantly improve times during a simulated 20-km time trial and therefore should not be recommended for use as an ergogenic aid.


Asunto(s)
Rendimiento Atlético/fisiología , Ciclismo/fisiología , Compuestos de Calcio/administración & dosificación , Lactatos/farmacología , Compuestos de Magnesio/administración & dosificación , Sustancias para Mejorar el Rendimiento/administración & dosificación , Adulto , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Humanos , Lactatos/administración & dosificación , Masculino , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/fisiología , Consumo de Oxígeno/efectos de los fármacos , Consumo de Oxígeno/fisiología , Esfuerzo Físico/efectos de los fármacos , Esfuerzo Físico/fisiología
6.
J Strength Cond Res ; 26(11): 3004-9, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22158094

RESUMEN

Saddle height is one of the most researched areas of bike fit. The current accepted method for adjusting saddle height involves the use of a goniometer to adjust saddle height so that a knee angle between 25° and 35° is obtained. This measurement is taken while the cyclist maintains a static position with the pedal at the 6-o'-clock position. However, the act of pedaling is dynamic, and angles may alter during movement. The purpose of this study was to examine the alterations to knee and ankle angle occurring from static measures to active pedaling across intensities experienced by cyclists during a graded exercise protocol. Thirty-four recreational to highly trained cyclists were evaluated using 2D analysis of stationary position and 3 active levels (level 1, respiratory exchange ratio of 1.00, and max). Dependent measures were compared using repeated measures analysis of variance (p = 0.05). When examining the results, it is evident that significant alterations to pedal stroke occur from stationary measures to active pedaling and as intensity increases toward maximal. Plantar flexion increased when moving from stationary measures to active pedaling, which resulted in an increase in knee angle. Although still greater than stationary measures, less plantar flexion occurred at higher intensities when compared with lower intensity cycling. Less plantar flexion at higher intensities is most likely a result of application of a larger downward torque occurring because of greater power requirements at higher intensities. There appeared to be greater variability in angle when examining novice cyclists in relation to more experienced cyclists. Although stationary measures are where a bike fit session will begin, observation during the pedal cycle may be needed to fine-tune the riders' fit.


Asunto(s)
Tobillo/fisiología , Ciclismo/fisiología , Rodilla/fisiología , Adulto , Análisis de Varianza , Fenómenos Biomecánicos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Consumo de Oxígeno , Intercambio Gaseoso Pulmonar , Descanso/fisiología , Equipo Deportivo
7.
J Strength Cond Res ; 25(3): 629-33, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20581695

RESUMEN

In cycling, saddle height adjustment is critical for optimal performance and injury prevention. A 25-35° knee angle is recommended for injury prevention, whereas 109% of inseam, measured from floor to ischium, is recommended for optimal performance. Previous research has demonstrated that these 2 methods produce significantly different saddle heights and may influence cycling performance. This study compared performance between these 2 methods for determining saddle height. Subjects consisted of 11 well-trained (VO2max = 61.55 ± 4.72 ml·kg·min) male cyclists. Subjects completed a total of 8 performance trials consisting of a graded maximal protocol, three 15-minute economy trials, and 4 anaerobic power trials. Dependent measures for economy (VO2, heart rate, and rating of perceived exertion) and anaerobic power (peak power and mean power) were compared using repeated measures analysis of variance (α = 0.05). VO2 was significantly lower (reflecting greater economy) at a 25° knee angle (44.77 ± 6.40 ml·kg·min) in comparison to a 35° knee angle (45.22 ± 6.79 ml·kg·min) and 109% of inseam (45.98 ± 5.33 ml·kg·min). Peak power at a 25° knee angle (1,041.55 ± 168.72 W) was significantly higher in relation to 109% of inseam (1,002.05 ± 147.65 W). Mean power at a 25° knee angle (672.37 ± 90.21 W) was significantly higher in relation to a 35° knee angle (654.71 ± 80.67 W). Mean power was significantly higher at 109% of inseam (662.86 ± 79.72 W) in relation to a 35° knee angle (654.71 ± 80.67 W). Use of 109% of inseam fell outside the recommended 25-35° range 73% of the time. Use of 25° knee angle appears to provide optimal performance while keeping knee angle within the recommended range for injury prevention.


Asunto(s)
Traumatismos en Atletas/prevención & control , Rendimiento Atlético/fisiología , Ciclismo/fisiología , Adulto , Atletas , Frecuencia Cardíaca/fisiología , Humanos , Rodilla/fisiología , Masculino , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Esfuerzo Físico/fisiología , Adulto Joven
8.
J Strength Cond Res ; 20(3): 519-22, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16937963

RESUMEN

The amount of adenosine triphosphate (ATP) stored in the muscle available for immediate use is limited, and once used, must be resynthesized in the muscle. Ribose, a naturally occurring pentose sugar, helps resynthesize ATP for use in muscles. There have been claims that ribose supplements increase ATP levels and improve performance. Other studies have provided mixed results on the effectiveness of ribose as an ergogenic aid at high doses. None of these studies have compared the impact of the recommended dose of ribose on athletes and nonathletes under exercise conditions that are most conducive for effectiveness. The purpose of this study was to evaluate the effectiveness of ribose as an ergogenic aid at the dose recommended for supplements currently on the market during an exercise trial to maximize its efficacy. Male subjects (n = 11) performed 2 trials 1 week apart. Each trial consisted of three 30-second Wingate tests with a 2-minute recovery between each test. Trials were counterbalanced, with 1 trial being performed with 625 mg of ribose and the other with a placebo. Peak power, mean power, and percent decrease in power were recorded during each Wingate test. Repeated-measures analysis of variance (p > 0.05) found no significant differences between ribose and placebo. These results suggest that ribose had no effect on performance when taken orally, at the dose suggested by the distributor.


Asunto(s)
Ciclismo/fisiología , Suplementos Dietéticos , Resistencia Física/efectos de los fármacos , Ribosa/farmacología , Análisis de Varianza , Estudios Cruzados , Método Doble Ciego , Prueba de Esfuerzo , Humanos , Masculino , Resistencia Física/fisiología , Aptitud Física/fisiología , Levantamiento de Peso/fisiología
9.
Eur J Appl Physiol ; 90(5-6): 608-13, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12923637

RESUMEN

This study compared respiratory compensation thresholds (RCT) ( VCO(2) inflection point) of competitors in highly aerobic events (aerobic competitors, ARC) ( n=16), competitors in highly anaerobic events (anaerobic competitors, ANC) ( n=15), and untrained subjects (UT) ( n=25). Maximal oxygen consumption ( VO(2max)), respiratory compensation threshold as a percentage of VO(2max) (RCT), and VO(2) at RCT ( Vdot;O(2RCT)) were determined during a maximal Bruce treadmill protocol. VO(2max) (ml x kg(-1) min(-1)) was significantly greater ( P<0.05) for ARC [67.2 (8.5)] than for ANC [50.0 (7.8)] and UT [43.8 (5.4)]. However, the difference between ANC and UT only approached significance ( P=0.07). RCT was not significantly different between ARC [76.3 (8.7)] and ANC [80.7 (6.8)] but was significantly lower ( P<0.05) for UT [62.5 (8.8)]. VO(2RCT) (ml x kg(-1) min(-1)) was significantly greater ( P<0.05) for ARC [51.6 (11.0)] and ANC [40.2 (6.6)] than for UT [27.4 (5.4)], with a significant difference also between ARC and ANC. While used as a criterion for group assignment, greater VO(2max), as well as RCT values in ARC (vs UT), reflect chronic aerobic training adaptations. ANC demonstrated VO(2max) values intermediate to ARC and UT, with RCT very comparable to those found in ARC. The results suggest subjects competitive in highly anaerobic events do not possess excessively high VO(2max) values. These individuals, however, demonstrate a high RCT when values are expressed relative to VO(2max). Oxygen consumption at the RCT in this group is superior to that in UT but inferior to that in ARC, which likely has important implications regarding performance.


Asunto(s)
Umbral Anaerobio/fisiología , Carrera/fisiología , Adaptación Fisiológica , Adulto , Femenino , Humanos , Masculino , Deportes
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