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  • Author: Michael G. Bemben x
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Michael J. Hartman, Brandon Clark, Debra A. Bemben, J. Lon Kilgore and Michael G. Bemben

Context:

Many elite athletes use increased daily training frequencies as a means to increase training load without substantial published literature to support this practice.

Purpose:

To compare the physiological responses to twice- and once-daily training sessions with similar training volumes.

Methods:

Ten nationally competitive male weightlifters (age 20.5 ± 1.2 y, body mass 92.9 ± 23.6 kg, training history 5.5 ± 1.5 y) were matched on body mass and training experience, then randomly assigned to train either once or twice daily for 3 wk. Isometric knee-extension strength (ISO), muscle cross-sectional area, vertical-jump peak power, resting hormone concentrations, neuromuscular activation (EMG), and weightlifting performance were obtained before and after the experimental training period.

Results:

All dependent measures before the training intervention were similar for both groups. A 2-way repeated-measures ANOVA did not reveal any significant main effects (group or trial) or interaction effects (group × trial) for any of the dependent variables. There were also no significant group differences when parameters were expressed as percentage change, but the twice-daily training group had a greater percentage change in ISO (+5.1% vs +3.2%), EMG (+20.3% vs +9.1%), testosterone (+10.5% vs +6.4%), and testosterone:cortisol ratio (−10.5% vs +1.3%) than did the once-daily training group.

Conclusions:

There were no additional benefits from increased daily training frequency in national-level male weightlifters, but the increase in ISO and EMG activity for the twice-daily group might provide some rationale for dividing training load in an attempt to reduce the risk of overtraining.

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Madoka Ogawa, Naotoshi Mitsukawa, Michael G. Bemben and Takashi Abe

Context:

Previous studies investigated the relationship between ultrasound-derived anatomical muscle thickness (MTH) and individual muscle cross-sectional area (CSA) and muscle volume in several limb and trunk muscles; however, the adductor muscle that contributes to hip adduction and pelvic stabilization, as well as balance ability, has not been studied.

Objective:

To examine the relationship between MTH of the lower, middle, and upper thigh measured by B-mode ultrasound and the muscle CSA and volume of adductor muscle obtained by magnetic resonance imaging (MRI) to confirm the possibility of predicting adductor muscle CSA/volume using ultrasound-derived MTH.

Setting:

University research laboratory.

Subjects:

10 men and 10 women (20–41 y old) volunteered to participate in this study.

Main Outcome Measures:

A series of continuous muscle CSAs along the thigh were measured by MRI scans (1.5-T scanner, GE Signa). In each slice, the anatomical CSA of the adductors was analyzed, and the muscle volume was calculated by multiplying muscle CSA by slice thickness. Thigh MTH was measured by B-mode ultrasound (Aloka SSD-500) at 5 sites (anterior 30%, 50%, and 70% and posterior 50% and 70% of thigh length).

Results:

A strong correlation was observed between anterior 30% MTH and 30% adductor CSA in men (r = .845, P < .002) and women (r = .952, P < .001) and in both groups combined (r = .922, P < .001). Anterior 30% MTH was also strongly correlated to adductor muscle volume when combined with thigh length (n = 20, r = .949, P < .001). However, there were moderate or nonsignificant correlations between anterior and posterior 50% and 70% MTH and adductor muscle CSA/volume.

Conclusions:

The results suggest that MTH in the upper portion of anterior thigh best reflects adductor muscle CSA or muscle volume, while the lower portions of the anterior and posterior sites are least likely to predict adductor muscle size.

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Jerry L. Mayhew, Michael G. Bemben and Donna M. Rohrs

The purpose of this study was to determine the relationships among the seated shot put (SSP), bench press power (BPP), and body composition in adolescent wrestlers. Seventy-five wrestlers from three high schools were tested during their preseason training. Upper body power was tested with a plate-loaded bench press machine equipped with infrared sensors attached to a digital timer. Each subject was given three trials with a constant 24.5-kg load (CLP) and with a variable load equal to 60% of body mass (VLP). Skinfolds were used to estimate body composition. The SSP was significantly related to both CLP and VLP as well as to body mass, lean body mass (LBM), and % fat. Removing the effect of body mass reduced the relationship between SSP and both CLP and VLP. Removing the effect of LBM had a slightly greater effect on the relationships between SSP and both CLP and VLP, although the correlations remained significant. Therefore it appears that the SSP is only moderately related to upper body power in adolescent wrestlers and may be greatly influenced by size and muscularity.

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Jerry L. Mayhew, Michael G. Bemben, Donna M. Rohrs, Fontaine C. Piper and Michael K. Willman

The purpose of this study was to compare the measurement of upper body power between male (n = 36) and female (n = 23) adolescent wrestlers and basketball players using the seated shot put (SSP) and a bench press power test (BPP). Boys were significantly different from girls on all physical and performance measures except age. The two SSP tests were significantly related to the two BPP tests in boys, but not in girls. Both SSP tests were significantly related to body mass and fat-free mass (FFM) in boys, but not in girls. Removing the effect of body mass or FFM reduced the relationships of both SSP tests with both BPP tests. BPP output was more dependent on age, height, and body mass in boys than in girls. The SSP may be measuring a different component of upper body power than a BPP test in either male or female adolescent athletes.