101
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Bartolini JA, Brown LE, Coburn JW, Judelson DA, Spiering BA, Aguirre NW, Carney KR, Harris KB. Optimal Elastic Cord Assistance for Sprinting in Collegiate Women Soccer Players. J Strength Cond Res 2011; 25:1263-70. [DOI: 10.1519/jsc.0b013e318215f575] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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102
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Muñoz CX, Judelson DA, Coburn JW, Becker AJ, Carney KR, Schick MK, Brown LE. Effects Of Drinking And External Cooling On Low Intensity Exercise And Performance In Hot-Dry Environments. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000403050.49056.2f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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103
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Judelson DA, Thomas WE, Coburn JW, Kersey RD, Rubin DA, Bagley JR, Ng J. Effect of Caffeine Supplementation on Catecholamine and Metabolic Responses to Exercise in Cold Conditions. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000401776.57960.3f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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104
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Trevino MA, Coburn JW, Brown LE, Judelson DA, Malek MH. Acute Effects of Caffeine on Strength and Muscle Activation of the Elbow Flexors. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000401769.19843.8f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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105
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Davis JT, Judelson DA, Brown LE, Coburn JW, Ellis CL, Ng J, Coats DR, Jennings CA. Effect Of Ambient Temperature On Thermoregulation, Perceptual Responses And Performance Of A 5000 m Run. Med Sci Sports Exerc 2011. [DOI: 10.1249/01.mss.0000403043.10938.d9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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106
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Marttinen RHJ, Judelson DA, Wiersma LD, Coburn JW. Effects of Self-Selected Mass Loss on Performance and Mood in Collegiate Wrestlers. J Strength Cond Res 2011; 25:1010-5. [DOI: 10.1519/jsc.0b013e318207ed3f] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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107
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Eurich AD, Brown LE, Coburn JW, Noffal GJ, Nguyen D, Khamoui AV, Uribe BP. Performance differences between sexes in the pop-up phase of surfing. J Strength Cond Res 2011; 24:2821-5. [PMID: 20733519 DOI: 10.1519/jsc.0b013e3181f0a77f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surfing is a dynamic sport that is multidirectional in nature and requires peak performance in variable ocean conditions. Its growing popularity among the female population has stirred curiosity as to whether women can and will 1 day face their male counterparts in head-to-head competition at the top levels. The purpose of this study was to examine male and female differences in performance of a simulated surfing pop-up movement. Forty recreationally trained surfers (20 men and 20 women) were instructed to lie prone on a force plate, in the pop-up position (similar to a push-up), with only their hands in contact with the plate. A velocity transducer was attached to their back via an adjustable strap around their upper trunk. They completed 3 pop-ups as explosively as possible by pushing forcefully with their hands and jumping to their feet. Absolute and relative force and power were measured. Results demonstrated that men exhibited significantly (p < 0.05) greater relative force (M = 9.56 ± 1.25 N·kg⁻¹, W = 8.15 ± 0.98) and relative power (M = 16.39 ± 4.22 W·kg⁻¹, W = 9.98 ± 2.58) when compared to women. These findings demonstrate that men produce greater force and power than do women even relative to body weight when performing a simulated surfing pop-up movement. It appears that women may be at a disadvantage in regards to peak performance when compared to their male counterparts in the surfing pop-up movement. Therefore, women should train for both maximum and explosive upper-body strength in addition to their time spent surfing.
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108
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Johnson TM, Brown LE, Coburn JW, Judelson DA, Khamoui AV, Tran TT, Uribe BP. Effect of four different starting stances on sprint time in collegiate volleyball players. J Strength Cond Res 2011; 24:2641-6. [PMID: 20885191 DOI: 10.1519/jsc.0b013e3181f159a3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Starting stance plays an important role in influencing short-distance sprint speed and, therefore, the ability to reach a ball during sport play. The purpose of this study was to evaluate 4 different starting stances on sprint time. Twenty-six male and female collegiate volleyball players volunteered to participate in 1 testing session. Each subject performed 3 15-ft sprint trials at each of 4 different starting stances (P-parallel, FS-false step, S-staggered, and SFS-staggered false step) in random order. Analysis of variance revealed that there was no significant interaction of sex by stance, but there were main effects for sex (men were faster than women) and stance. The FS (1.18 ± 0.10 seconds), S (1.16 ± 0.07 seconds), and SFS (1.14 ± 0.06 seconds) stances were faster than the P (1.25 ± 0.09 seconds) stance, and the SFS stance was faster than the FS stance. This indicates that starting with a staggered stance (regardless of stepping back) produced the greatest sprinting velocity over the initial 15 feet. Although taking a staggered stance seems counterproductive, the resultant stretch-shortening cycle action and forward body lean likely increase force production of the push-off phase and place the total body center of mass ahead of the contacting foot, thereby, decreasing sprint time.
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109
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Khamoui AV, Brown LE, Nguyen D, Uribe BP, Coburn JW, Noffal GJ, Tran T. Relationship Between Force-Time and Velocity-Time Characteristics of Dynamic and Isometric Muscle Actions. J Strength Cond Res 2011; 25:198-204. [DOI: 10.1519/jsc.0b013e3181b94a7b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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110
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Cherry EA, Brown LE, Coburn JW, Noffal GJ. Effect of Remote Voluntary Contractions on Knee Extensor Torque and Rate of Velocity Development. J Strength Cond Res 2010; 24:2564-9. [DOI: 10.1519/jsc.0b013e3181e7f961] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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111
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Dabbs NC, Brown LE, Coburn JW, Lynn SK, Biagini MS, Tran TT. Effect of whole-body vibration warm-up on bat speed in women softball players. J Strength Cond Res 2010; 24:2296-9. [PMID: 20683351 DOI: 10.1519/jsc.0b013e3181eccde5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Whole-body vibration (WBV) may enhance human performance via augmented muscular strength and motor function if used before performance. Because warm-up is a crucial aspect of preparation for performance, it remains unknown if WBV may enhance bat speed. The purpose of this study was to investigate the effect of WBV warm-up on bat speed. Eleven National Collegiate Athletic Association division I and 11 recreationally trained female softball players volunteered to participate. Subjects randomly performed 3 different warm-up conditions consisting of WBV alone, dry swings alone (DS), and WBV with dry swings (WBVDS). Whole-body vibration was performed on a pivotal vibration platform at a frequency of 25 Hz and an amplitude of 13 mm for one 30-second bout. Thirty seconds after each warm-up condition, 5 maximal bat swings were recorded. There was no significant (p > 0.05) difference between groups by training status, and there was no significant (p > 0.05) difference between WBV (42.39 +/- 9.83 mph), DS (40.45 +/- 11.00 mph), or WBVDS (37.98 +/- 12.40 mph) conditions. These results indicate that WBV warm-up may be used in place of DS to achieve similar bat speeds. Future research should investigate different combinations of WBV warm-up using various frequencies, durations, amplitudes, and rest times.
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112
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Rapisura KP, Coburn JW, Brown LE, Kersey RD. Physiological variables and mouthguard use in women during exercise. J Strength Cond Res 2010; 24:1263-8. [PMID: 20386126 DOI: 10.1519/jsc.0b013e3181d1572d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although mouthguards have been found to reduce injury, many athletes choose not to use them because of the belief of negative effects on breathing with mouthguard use. Therefore, this study investigated the effects of mouthguard use on physiological variables in women using a self-adapted mouthguard made for women and a universal self-adapted mouthguard. Eleven subjects (mean +/- SD; age: 22 +/- 3.3 y; height: 159.8 +/- 4.3 cm; body mass: 63.7 +/- 8.9 kg) performed 3 separate maximal cycle ergometer tests with either 1 mouthguard or no mouthguard. Heart rate (HR), rating of perceived exertion (RPE), oxygen consumption VO2), minute ventilation VE), and respiratory exchange ratio (RER) were measured at each exercise intensity and at the end of each test. HR, RPE, and VO2 increased for each mouthguard condition across power levels. VE and RER increased more from 110W to max with the no mouthguard condition than for either mouthguard. However, there was no significant difference in VE or RER at any given power level between mouthguard conditions. The results indicated mouthguard use did not affect HR, RPE, VE, VO2, or RER at any given power level during exercise, including the guard made specifically for women. Therefore, athletes are encouraged to use mouthguards without fear of negative aerobic performance effects.
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113
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Malek MH, Coburn JW, York R, Ng J, Rana SR. Comparison of mechanomyographic sensors during incremental cycle ergometry for the quadriceps femoris. Muscle Nerve 2010; 42:394-400. [DOI: 10.1002/mus.21686] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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114
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Chattong C, Brown LE, Coburn JW, Noffal GJ. Effect of a Dynamic Loaded Warm-Up on Vertical Jump Performance. J Strength Cond Res 2010; 24:1751-4. [DOI: 10.1519/jsc.0b013e3181ddf665] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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115
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Schick EE, Coburn JW, Brown LE, Judelson DA, Khamoui AV, Tran TT, Uribe BP. A comparison of muscle activation between a Smith machine and free weight bench press. J Strength Cond Res 2010; 24:779-84. [PMID: 20093960 DOI: 10.1519/jsc.0b013e3181cc2237] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The bench press exercise exists in multiple forms including the machine and free weight bench press. It is not clear though how each mode differs in its effect on muscle activation. The purpose of this study was to compare muscle activation of the anterior deltoid, medial deltoid, and pectoralis major during a Smith machine and free weight bench press at lower (70% 1 repetition maximum [1RM]) and higher (90% 1RM) intensities. Normalized electromyography amplitude values were used during the concentric phase of the bench press to compare muscle activity between a free weight and Smith machine bench press. Participants were classified as either experienced or inexperienced bench pressers. Two testing sessions were used, each of which entailed either all free weight or all Smith machine testing. In each testing session, each participant's 1RM was established followed by 2 repetitions at 70% of 1RM and 2 repetitions at 90% of 1RM. Results indicated greater activation of the medial deltoid on the free weight bench press than on the Smith machine bench press. Also, there was greater muscle activation at the 90% 1RM load than at the 70% 1RM load. The results of this study suggest that strength coaches should consider choosing the free weight bench press over the Smith machine bench press because of its potential for greater upper-body muscular development.
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116
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Jo E, Judelson DA, Brown LE, Coburn JW, Dabbs NC. Influence of recovery duration after a potentiating stimulus on muscular power in recreationally trained individuals. J Strength Cond Res 2010; 24:343-7. [PMID: 20072066 DOI: 10.1519/jsc.0b013e3181cc22a4] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Research examining postactivation potentiation (PAP) in recreationally trained individuals (RTI) shows mixed results. Because the balance of PAP and fatigue after heavy-load exercise influences performance outcomes, recovery duration after the stimulus might explain inconsistent results noted in RTI. The purpose of this study was to investigate the effect of recovery duration after a potentiating stimulus on muscular power in RTI. Twelve healthy RTI males (age = 23 +/- 1 yr, height = 174.6 +/- 2.5 cm, mass = 86.3 +/- 6.6 kg, 1 repetition maximum [1RM]:mass = 1.4 +/- 0.1, body fat = 15.1 +/- 2.5 %) minimally possessing 1 year of back squat experience participated. A control session assessed baseline measures on a 30-second Wingate Test. During experimental sessions, subjects performed a back squat exercise (1 set of 5 repetitions at 85% 1RM), rested for 5, 10, 15, or 20 minutes, and performed the Wingate Test. No significant differences existed among control and experimental conditions in all outcome variables; however, maximal values (regardless of rest duration) for absolute peak power (APpwr) (+7.1%), relative peak power (RPpwr) (+7.1%), and fatigue index (FI) (+8.9%) significantly differed from respective control values. The rest duration eliciting maximal PAP significantly correlated (r = -0.771) with relative 1RM. Although recovery duration failed to influence performance after a heavy-load exercise in RTI, discrepancies in individual strength might have influenced the time subjects potentiated. These results suggest stronger subjects might potentiate with less rest after a stimulus (5-10 min), whereas weaker subjects require longer rest durations (15-20 min).
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117
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Dabbs NC, Brown LE, Coburn JW, Lynn SK, Biagini MS, Tran TT. Effect Of Whole-body Vibration Warm-up On Bat Speed. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000384482.21703.f2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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118
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Schick EE, Coburn JW, Brown LE, Judelson DA, Khamoui AV, Tran TT, Uribe BP. Comparison Of 1RM Strength And Muscle Activation Between The Smith Machine And Free Weight Bench Press In Experienced And Inexperienced Lifters. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000384409.98097.95] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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119
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Tran TT, Brown LE, Coburn JW, Lynn SK, Dabbs NC, Gochioco MK, Schick EE, Khamoui AV, Uribe BP, Noffal GJ. Effects Of Different Levels Of Assisted Jumping On Vertical Jump Height And Relative Ground Reaction Force. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000384662.00137.eb] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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120
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Thomas WE, Judelson DA, Bagley JR, Coburn JW, Kersey RD, Rubin DA. Effect Of Caffeine Supplementation On Cycling Performance During Cold Stress. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000385976.10578.b1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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121
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Jo E, Martinez M, Lee BE, Coburn JW, Matthew B, Gochioco M, Judelson DA. Effects Of Caffeine On Resistance Exercise Performance, Mood, Heart Rate, And Rating Of Perceived Exertion. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000384998.72523.6b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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122
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Stevens HB, Brown LE, Coburn JW, Spiering BA. Effect of Swim Sprints on Throwing Accuracy and Velocity in Female Collegiate Water Polo Players. J Strength Cond Res 2010; 24:1195-8. [DOI: 10.1519/jsc.0b013e3181d82d3b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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123
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Gochioco MK, Schick EE, Dabbs NC, Khamoui AV, Tran TT, Brown LE, Coburn JW, Beam WC. Physiological Profile of Amateur Mixed Martial Artists. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000386626.85052.ea] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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124
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Uribe BP, Coburn JW, Brown LE, Judelson DA, Khamoui AV, Nguyen D. Muscle Activation When Performing the Chest Press and Shoulder Press on a Stable Bench vs. a Swiss Ball. J Strength Cond Res 2010; 24:1028-33. [DOI: 10.1519/jsc.0b013e3181ca4fb8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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125
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Nguyen D, Brown LE, Coburn JW, Judelson DA, Eurich AD, Khamoui AV, Uribe BP. Effect of delayed-onset muscle soreness on elbow flexion strength and rate of velocity development. J Strength Cond Res 2009; 23:1282-6. [PMID: 19568034 DOI: 10.1519/jsc.0b013e3181970017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Eccentric muscle actions cause muscle damage and lead to delayed-onset muscle soreness (DOMS), which may impair performance. The purpose of this study was to examine the effect of DOMS on elbow flexion strength and rate of velocity development (RVD). Nineteen college male subjects performed 6 tests (pre- and posteccentric and every 24 hours for 4 days). In the preeccentric tests, each subject reported his arm pain and then did 5 concentric repetitions of elbow flexion/extension on an isokinetic dynamometer at 240 degrees x s(-1). Each subject then completed 6 sets of 10 eccentric elbow flexion actions at 30 degrees x s(-1) and finished with a posteccentric test with another 5 concentric repetitions at 240 degrees x s(-1). On days 1-4, each subject reported his arm pain and then did 5 more repetitions at 240 degrees x s(-1). Analysis was performed on the values for DOMS, peak torque (PT), and RVD. For DOMS, scores on the posteccentric test (2.34 +/- 2.53), day 1 (3.18 +/- 2.18), day 2 (3.21 +/- 2.91), day 3 (1.81 +/- 1.78), and day 4 (1.02 +/- 1.30) were all significantly (p < 0.05) greater than the preeccentric scores (0.00 +/- 0.00). For PT, the scores on the posteccentric test (22.40 +/- 8.87 ft x lb(-1)) and day 1 (23.88 +/- 9.00 ft x lb(-1)) were both significantly less than on the preeccentric test (29.56 +/- 8.42 ft x lb(-1)). The RVD scores on the posteccentric test (1505.73 +/- 462.12 d x s(-1) x s(-1)), day 1 (1571.55 +/- 475.99 d x s(-1) x s(-1)), and day 2 (1546.99 +/- 494.52 d x s(-1) x s(-1)) were all significantly less than on the preeccentric test (1719.86 +/- 473.18 d x s(-1) x s(-1)). This suggests that muscle damage may cause significant decreases in elbow flexion concentric strength and RVD even as DOMS remains elevated.
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126
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Montoya BS, Brown LE, Coburn JW, Zinder SM. Effect of Warm-up With Different Weighted Bats on Normal Baseball Bat Velocity. J Strength Cond Res 2009; 23:1566-9. [DOI: 10.1519/jsc.0b013e3181a3929e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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127
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Khamoui AV, Brown LE, Coburn JW, Judelson DA, Uribe BP, Nguyen D, Tran T, Eurich AD, Noffal GJ. Effect of Potentiating Exercise Volume on Vertical Jump Parameters in Recreationally Trained Men. J Strength Cond Res 2009; 23:1465-9. [DOI: 10.1519/jsc.0b013e3181a5bcdd] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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128
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Malek MH, Coburn JW, Tedjasaputra V. Comparison of electromyographic responses for the superficial quadriceps muscles: Cycle versus knee-extensor ergometry. Muscle Nerve 2009; 39:810-8. [DOI: 10.1002/mus.21295] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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129
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Malek MH, Coburn JW. A new ventilatory threshold equation for aerobically trained men and women. Clin Physiol Funct Imaging 2009; 29:143-50. [PMID: 19207417 DOI: 10.1111/j.1475-097x.2008.00850.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purposes of the present study were to (i) modify previously published ventilatory threshold (VT) equations using the constant error (CE) values for aerobically trained individuals from a recent study; (ii) cross-validate the modified equations to determine their accuracy for estimating VT in aerobically trained individuals; (iii) derive a new non-exercise based equation for estimating VT in aerobically trained individuals if the modified equations are found to be inaccurate; and (iv) cross-validate the new VT equation using the Predicted REsidual Sum of Squares (PRESS) statistic and an independent sample of aerobically trained individuals. Two hundred and eight (n = 208) aerobically trained men and women (mean +/- SD: age = 38.8 +/- 10.4 year) performed a maximal incremental test on a cycle ergometer to determine the observed VT. The predicted VT values from seven published equations were compared with the observed VT by examining the CE, standard error of estimate, validity coefficient (r), and total error (TE). Cross-validation of the modified equations resulted in high %TE values. Therefore, a new VT equation was derived. Cross-validation of this equation on an independent sample of 72 subjects resulted in a low %TE value. The new model is recommended over previous models for estimating VT in aerobically trained individuals.
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130
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Jo E, Judelson DA, Brown LE, Coburn JW, Dabbs NC, Uribe BP. Influence Of Recovery Duration Following A Potentiating Stimulus On Muscular Power In Recreationally Trained Individuals. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000355017.92025.3b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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131
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Uribe BP, Khamoui AV, Tran T, Nguyen D, Brown LE, Coburn JW, Judelson DA. Sex Differences In Hamstring Relative Torque. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000354966.17575.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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132
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Altamirano KM, Coburn JW, Brown LE, Judelson DA. Effects Of Warm-up On Peak Torque, Rate Of Torque Development, And Electromyographic And Mechanomyographic Signals. Med Sci Sports Exerc 2009. [DOI: 10.1249/01.mss.0000354961.23855.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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133
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Kelly SB, Brown LE, Coburn JW, Zinder SM, Gardner LM, Nguyen D. The effect of single versus multiple sets on strength. J Strength Cond Res 2008; 21:1003-6. [PMID: 18076273 DOI: 10.1519/r-22356.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Research has previously been divided on whether performing resistance training with a single set per training session is as effective for increasing strength as training with multiple sets. The purpose of this study was to determine the effect of single sets versus multiple sets on strength. Forty subjects were randomly assigned into 1 of 3 groups: control (C; n = 8), single set (SS; n = 14), or multiple sets (MS; n = 18) to perform 8 maximal knee extensions at 60 degrees .s(-1) on a Biodex System 3 isokinetic dynamometer twice a week for 8 weeks. The SS group performed 1 set while the MS group performed 3 sets. All groups were pre-, mid- (4 weeks), and posttested at 60 degrees x s(-1). Strength was expressed as peak torque (PT). A 3 x 3 x 2 (time x group x sex) mixed factor repeated measures analysis of variance (ANOVA) revealed no interaction involving sex, but there was an interaction of group by time. The MS group exhibited a significant (p < 0.05) increase in PT (pre = 171.39 +/- 61.98 Nm; mid = 193.08 +/- 66.23 Nm) between the pretest and the midtest while the SS (pre = 163.45 +/- 56.37 Nm; mid = 172.60 +/- 61.78 Nm) and C groups (pre = 135.997 +/- 54.31 Nm; mid = 127.66 +/- 53.12 Nm) did not change. Strength did not change between the midtest and the posttest for any group. It was concluded that performing 3 sets of isokinetic knee extensions was more effective than performing a single set for increasing peak torque. These results seem to indicate that for increasing strength of the quadriceps, performing multiple sets is superior to performing a single set of resistance exercise.
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134
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Uribe B, Nguyen D, Nishimura K, Brown LE, Coburn JW, Judelson DA. Relationship Between Maximum Isometric Force And Maximum Velocity. Med Sci Sports Exerc 2008. [DOI: 10.1249/01.mss.0000322410.59300.92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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135
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Nguyen D, Uribe B, Nishimura K, Brown LE, Coburn JW, Judelson DA. Gender Effects On Dynamic Rvd And Static Rfd. Med Sci Sports Exerc 2008. [DOI: 10.1249/01.mss.0000322409.51677.a2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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136
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Weber KR, Brown LE, Coburn JW, Zinder SM. Acute Effects of Heavy-Load Squats on Consecutive Squat Jump Performance. J Strength Cond Res 2008; 22:726-30. [PMID: 18438248 DOI: 10.1519/jsc.0b013e3181660899] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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137
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Coburn JW, Malek MH, Brown LE. Interlimb Comparison of the Mechanomyographic Time and Frequency Domain Responses of the Vastus Medialis. Med Sci Sports Exerc 2008. [DOI: 10.1249/01.mss.0000323403.85790.c1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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138
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Malek MH, Coburn JW. Strategies for cardiopulmonary exercise testing of pectus excavatum patients. Clinics (Sao Paulo) 2008; 63:245-54. [PMID: 18438580 PMCID: PMC2664209 DOI: 10.1590/s1807-59322008000200014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 12/29/2007] [Indexed: 11/22/2022] Open
Abstract
The purpose of this paper is to provide strategies for cardiopulmonary exercise testing of pectus excavatum patients. Currently, there are no standardized methods for assessing cardiovascular and pulmonary responses in this population; therefore, making comparisons across studies is difficult if not impossible. These strategies are intended for physicians, pulmonary technicians, exercise physiologists, and other healthcare professionals who conduct cardiopulmonary exercise testing on pectus excavatum patients. By using the strategies outlined in this report, comparisons across studies can be made, and the effects of pectus excavatum on cardiopulmonary function can be assessed with greater detail.
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139
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Coburn JW, Malek MH, Brown LE, Zinder SM. Mechanomyographic responses of the superficial quadriceps femoris muscles to incremental isometric muscle actions. ELECTROMYOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 2008; 48:97-102. [PMID: 18435213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The purpose of this study was to compare the composite and individual relationships for mechanomyographic (MMG) amplitude vs. torque during incremental isometric muscle actions. Ten women and six men (mean age +/- SD = 21.8 +/- 1.6 y) performed isometric leg extension muscle actions at 10-100% of peak isometric torque. Accelerometers were placed over the superficial quadriceps femoris muscles to detect the MMG signals. Polynomial regression analyses were used to determine the composite and individual patterns for MMG amplitude vs. isometric torque. The results indicated that the composite MMG amplitude vs. isometric torque relationships for all subjects combined were quadratic for the vastus lateralis and vastus medialis, and linear for the rectus femoris. The results of the individual analyses for the vastus lateralis revealed that the best fit model was linear for six subjects, quadratic for five subjects, cubic for three subjects, while two subjects exhibited no significant relationship. For the rectus femoris, eight subjects demonstrated linear patterns, six were quadratic, and two were cubic. For the vastus medialis, six subjects demonstrated linear patterns, four were quadratic, four were cubic, and two demonstrated no significant relationship. Examination of the patterns between muscles for each individual subject demonstrated that twelve of the sixteen subjects demonstrated different patterns for MMG amplitude vs. isometric torque for at least two of the three muscles examined. The results indicated there were differences in the patterns of responses for the composite MMG amplitude vs. isometric torque relationships for the three muscles. Furthermore, individual patterns for MMG amplitude frequently differed from the composite patterns, as well as between muscles. The results suggested that, in addition to using composite results of MMG responses, individual subject responses should be examined. Furthermore, caution should be used in generalizing the MMG responses of the quadriceps femoris muscles when examining a single muscle.
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140
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McClenton LS, Brown LE, Coburn JW, Kersey RD. The Effect of Short-Term VertiMax vs. Depth Jump Training on Vertical Jump Performance. J Strength Cond Res 2008; 22:321-5. [DOI: 10.1519/jsc.0b013e3181639f8f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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141
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Malek MH, Berger DE, Marelich WD, Coburn JW. On the application of meta-analysis in pectus excavatum research. Am J Cardiol 2008; 101:415-7. [PMID: 18237612 DOI: 10.1016/j.amjcard.2007.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 07/18/2007] [Accepted: 07/18/2007] [Indexed: 11/27/2022]
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142
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Beck TW, Housh TJ, Johnson GO, Schmidt RJ, Housh DJ, Coburn JW, Malek MH, Mielke M. Effects of a protease supplement on eccentric exercise-induced markers of delayed-onset muscle soreness and muscle damage. J Strength Cond Res 2007; 21:661-7. [PMID: 17685720 DOI: 10.1519/r-21016.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This investigation examined the effects of a protease supplement on selected markers of muscle damage and delayed-onset muscle soreness (DOMS). The study used a double-blinded, placebo-controlled, crossover design. Twenty men (mean +/- SD age = 21.0 +/- 3.1 years) were randomly assigned to either a supplement group (SUPP) or a placebo group (PLAC). All subjects were tested for unilateral isometric forearm flexion strength, hanging joint angle, relaxed arm circumference, subjective pain rating, and plasma creatine kinase activity and myoglobin concentration. The testing occurred before (TIME1), immediately after (TIME2), and 24 (TIME3), 48 (TIME4), and 72 (TIME5) hours after a bout of eccentric exercise. During these tests, the subjects in the SUPP group ingested a protease supplement. The subjects in the PLAC group took microcrystalline cellulose. After testing at TIME5 and 2 weeks of rest, the subjects were crossed over into the opposite group and performed the same tests as during visits 1-5, but with the opposite limb. Overall, isometric forearm flexion strength was greater (7.6%) for the SUPP group than for the PLAC group, despite nearly identical (difference = 0.14 N.m, p = 0.940) mean strength values before (TIME1) the eccentric exercise protocol. There were no between-group differences for hanging joint angle, relaxed arm circumference, subjective pain ratings, and plasma creatine kinase activity and myoglobin concentration from TIME1 to TIME5. These findings provided initial evidence that the protease supplement may be useful for reducing strength loss immediately after eccentric exercise and for aiding in short-term strength recovery. The protease supplement had no effect, however, on the perception of pain associated with DOMS or the blood markers of muscle damage.
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143
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Beck TW, Housh TJ, Johnson GO, Weir JP, Cramer JT, Coburn JW, Malek MH, Mielke M. Effects of two days of isokinetic training on strength and electromyographic amplitude in the agonist and antagonist muscles. J Strength Cond Res 2007; 21:757-62. [PMID: 17685705 DOI: 10.1519/r-20536.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to examine the effects of 2 days of isokinetic training of the forearm flexors and extensors on strength and electromyographic (EMG) amplitude for the agonist and antagonist muscles. Seventeen men (mean +/- SD age = 21.9 +/- 2.8 years) were randomly assigned to 1 of 2 groups: (a) a training group (TRN; n = 8), or (b) a control group (CTL; n = 9). The subjects in the TRN group were tested for maximal isometric and concentric isokinetic (randomly ordered velocities of 60, 180, and 300 degrees x s(-1)) torque of the dominant forearm flexors and extensors before (pretest) and after (posttest) 2 days of isokinetic strength training. Each training session involved 6 sets of 10 maximal concentric isokinetic muscle actions of the forearm flexors and extensors at a velocity of 180 degrees x s(-1). The subjects in the CTL group were also tested for strength but did not perform any training. Surface EMG signals were detected from the biceps brachii and triceps brachii muscles during the strength testing. The results indicated that there were no significant (p > 0.05) pre- to post-test changes in forearm flexion and extension torque or EMG amplitude for the agonist and antagonist muscles. Thus, unlike previous studies of the quadriceps femoris muscles, these findings for the forearm flexors and extensors suggested that 2 days of isokinetic training may not be sufficient to elicit significant increases in strength. These results may have implications for the number of visits that are required for rehabilitation after injury, surgery, or both.
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144
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Malek MH, Berger DE, Coburn JW. On the inappropriateness of stepwise regression analysis for model building and testing. Eur J Appl Physiol 2007; 101:263-4; author reply 265-6. [PMID: 17520270 DOI: 10.1007/s00421-007-0485-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2007] [Indexed: 10/23/2022]
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145
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Kelly SB, Brown LE, Coburn JW, Zinder SM, Gardner LM, Nguyen D. Effect of Single Vs. Multiple Sets for Strength. Med Sci Sports Exerc 2007. [DOI: 10.1249/01.mss.0000274866.32132.1b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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146
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Malek MH, Coburn JW, Weir JP, Beck TW, Housh TJ. The Relationship Between Mechanomyographic Responses Of The Superficial Quadriceps Muscles And Excess Post-exercise Oxygen Consumption Following Constant Power Output Cycle Ergometry. Med Sci Sports Exerc 2007. [DOI: 10.1249/01.mss.0000274339.36520.9e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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147
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Coburn JW, Malek MH, Brown LE, Zinder SM. Mechanomyographic Responses of the Superficial Quadriceps Femoris Muscles to Incremental Isometric Muscle Actions. Med Sci Sports Exerc 2007. [DOI: 10.1249/01.mss.0000274716.99813.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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148
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Hendrix CR, Beck TW, Housh TJ, Johnson GO, Weir JP, Cramer JT, Coburn JW, Malek MH, Mielke M. Effects of Very Short-term, Unilateral, Isokinetic TVaining of the forearm flexors on Strength in the TVained and Untrained Limbs. Med Sci Sports Exerc 2007. [DOI: 10.1249/01.mss.0000274151.28033.d2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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149
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Nguyen D, Brown LE, Gardner LM, Coburn JW, Zinder SM, Kelly SB. The Effect Of Sex On Isokinetic Knee Extension Total Work. Med Sci Sports Exerc 2007. [DOI: 10.1249/01.mss.0000274187.74185.49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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150
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Malek MH, Housh TJ, Coburn JW, Schmidt RJ, Beck TW. Cross-validation of ventilatory threshold prediction equations on aerobically trained men and women. J Strength Cond Res 2007; 21:29-33. [PMID: 17313275 DOI: 10.1519/00124278-200702000-00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this investigation was to determine the validity of the non-exercise-based equations of Davis et al. (13), Jones et al. (20), and Neder et al. (30) for estimating the ventilatory threshold (VT) in samples of aerobically trained men and women. One hundred and forty-four aerobically trained men (mean +/- SD age, 41.0 +/- 11.6 years; N = 83) and women (37.1 +/- 9.0 years, N = 61) performed a maximal incremental test to determine VO2max and observed VT on a cycle ergometer. The observed VT was determined by gas exchange measurements using the V-slope method (VCO2/VO2) in conjunction with analyses of the ventilatory equivalents (i.e., minute ventilation VE/VO2 and VE/VCO2) and end-tidal gas tensions (i.e., P(ET)O2 and P(ET)CO2) for oxygen and carbon dioxide. The predicted VT values from 14 equations were compared to the observed VT values by examining the constant error (CE), standard error of estimate (SEE), Pearson correlation coefficient (r), and total error (TE). The results of this investigation indicated that all 14 equations resulted in significant (p < 0.008) CE values ranging from 1.13 to 1.72 L x min(-1) for the men and from 0.58 to 1.12 L x min(-1) for the women. Furthermore, the SEE, r, and TE values ranged from 0.37 to 0.54, from 0.36 to 0.53, and from 0.68 to 1.81 L x min(-1), respectively. The lowest TE values for the men and women represented 45 and 36% of the mean of the observed VT values, respectively. The results of this study indicated that the errors associated with all 14 equations were too large to be of practical value for estimating VT in aerobically trained men and women.
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