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Computerized agility training (CAT) products are frequently suggested to improve agility. However, these claims often are made without unbiased scientific support. Therefore, the purpose of this study was (a) to determine the reliability and effectiveness of a 4-week CAT training program on foot speed (FS) and choice reaction (REACT), and (b) to assess whether training on the CAT would facilitate the improvement of a separate change-of-direction (COD) test in non-agility-trained, but active, men and women. Twenty-three participants (15 men, 8 women) pre- and posttested on FS, REACT, and COD drills. Eleven of those participants (7 men, 4 women) engaged in 4 weeks of training on the FS and REACT drills (EX). The remaining 12 (8 men, 4 women) did not participate in the training and served as controls (CON). Coefficients of variation indicate strong precision for FS (6.9%) and REACT (2.6%). Test-retest reliability, as analyzed by intraclass correlations (ICC), were high for both FS and REACT (0.89). Significant test-by-group interactions were observed for all three tests: FS (p = 0.004), REACT (p = 0.011), and COD (p = 0.049). Post hoc analysis indicated that EX increased foot contacts for the FS drill (p = 0.006), whereas REACT and COD demonstrated decreases in time to completion (p = 0.013 and 0.038, respectively). The CON group did not improve on any of the tests. This study indicates that the chosen CAT is an accurate and reliable tool for measuring foot speed and reaction time. These data justify the use of this CAT in analyzing foot speed and reaction time. Altogether, 4 weeks of foot speed and reaction training on the chosen CAT produced improvements in overall agility in non-agility-trained, but active, men and women. These data warrant the integration of such a device into the training program of untrained athletes attempting to improve agility. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the influence of myosin heavy chain (MHC) isoform composition and training status on the mechanomyographic (MMG) amplitude versus isometric torque relationship for the vastus lateralis. Five resistance-trained (mean +/- SD age = 23.2 +/- 3.7 years), 5 aerobically trained (mean +/- SD age = 32.6 +/- 5.2 years), and 5 sedentary (mean +/- SD age = 23.4 +/- 4.1 years) men performed isometric muscle actions of the leg extensors in 20% increments from 20% to 100% of the maximum voluntary contraction. Biopsies from the vastus lateralis revealed that the MHC composition for the resistance-trained subjects was 59.0 +/- 4.2% Type IIa, 0.1 +/- 0.1% Type IIx, and 40.9 +/- 4.3% Type I. The aerobically-trained subjects had 27.4 +/- 7.8% Type IIa, 0.0 +/- 0.0% Type IIx, and 72.6 +/- 7.8% Type I MHC. The sedentary subjects had 42.1 +/- 7.8% Type IIa, 17.8 +/- 6.4% Type IIx, and 40.1 +/- 10.9% Type I MHC. There were no consistent patterns of responses for the resistance-trained, aerobically trained, or sedentary subjects for MMG amplitude versus torque. Thus, differences in MHC isoform composition and training status did not explain the unique torque-related patterns for MMG amplitude. [ABSTRACT FROM AUTHOR]

Weightlifting exercises and methods are essential for the strength and conditioning professional. This article reviews the underlying physiology and biomechanics of these exercises and training methods. [ABSTRACT FROM AUTHOR]

To determine the effects of 12 weeks of resistance exercise with MYOVIVE and/or colostrum supplementation, 19 male and female recreationally weight-trained subjects (X +/- SE; age = 28.3 +/- 6.9 yrs; hgt = 68.2 +/- 3.8 cm) were divided into MYOVIVE + colostrum (n = 4), MYOVIVE + casein & whey (n = 4), colostrum + casein & whey (n = 6), and casein & whey (n = 5) groups. All groups similarly increased (p < .05) 1 repetition maximum (RM) leg press (kg; pre = 158.6 +/- 12.8, post = 189.3 +/- 11.3), body mass (kg; pre = 79.0 +/- 3.2, post = 80.7 +/- 3.8), and lean body mass (kg; pre = 60.1 +/- 3.1, post = 62.2 +/- 2.8). Increases were observed for peak force (N; all loads), peak velocity (m x s[-1]; 70% & 40% 1 RM), and peak power (W; 70% & 40% 1 RM) for all groups for the leg press exercise, with no differences between groups. When performance data were adjusted for body mass, lean body mass, lower body lean mass as determined by DEXA, or % change, no group differences were observed. Relative (%) fiber type content, cross-sectional areas (microm[2]), % fiber type areas, or % myosin heavy chain expression did not change for any group. These data suggest that MYOVIVE and colostrum supplementation have no greater effect on cellular and performance adaptations when compared to casein and whey protein. [ABSTRACT FROM AUTHOR]

Objective: To compare immune function in female rowers and controls in the resting state, and then correlate the results with a two month history of upper respiratory tract infection (URTI).Methods: Subjects included 20 elite female rowers located at the ARCO Olympic Training Centre in Chula Vista, California, and 19 non-athletic female controls. These two groups were compared cross sectionally for immune function and infection rates.Results: Granulocyte/monocyte phagocytosis, oxidative burst activity, and plasma cytokine concentrations (interleukin-6, tumour necrosis factor-alpha, and interleukin-1 receptor antagonist) did not differ significantly between groups. Phytohaemagglutinin induced lymphocyte proliferative response (adjusted whole blood method) was significantly higher (31% and 36% for optimal and suboptimal concentrations respectively) in rowers than in controls. Natural killer cell activity was substantially higher (1.6-fold for total lytic units) in the female rowers than in controls. Two month health logs disclosed 5.2 (1.2) and 3.3 (1.1) days with URTI symptoms for the rowers and controls respectively (p = 0.268). For all 39 subjects combined, and for the 20 rowers separately, none of the immune parameters correlated significantly with number of days with URTI symptoms.Conclusions: In this cross sectional comparison of elite female rowers and non-athletes, a group difference was found for natural killer cell activity and phytohaemagglutinin induced proliferative response (whole blood technique), but not other measures of immune function. The number of days with URTI symptoms during the spring season did not differ between groups, and variations in blood measures of immunity were unrelated to URTI. [ABSTRACT FROM AUTHOR]

Weightlifting exercises, including the snatch and clean, are an important component in the strength and conditioning programs of athletes. The stop snatch and stop clean are variations that are effective for improving performance and technique. [ABSTRACT FROM AUTHOR]