Journal of strength and conditioning research
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J Strength Cond Res · Jan 2012
The validity of multifrequency bioelectrical impedance measures to detect changes in the hydration status of wrestlers during acute dehydration and rehydration.
The objective of this study was to examine the validity of multifrequency direct segmental bioelectrical impedance analysis (DSM-BIA) measures to detect changes in the hydration status of wrestlers after they underwent 3% acute dehydration and a 2-hour rehydration period. Fifty-six National Collegiate Athletic Association wrestlers: (mean ± SEM); age 19.5 ± 0.2 years, height 1.73 ± 0.01 m, and body mass (BM) 82.5 ± 2.3 kg were tested in euhydrated, dehydrated (-3.5%), and 2-hour rehydration conditions using DSM-BIA to detect the changes in hydration status. The hydration status was quantified by measuring the changes in plasma osmolality (P(osm)), urine osmolality (Uosm), urine specific gravity (U(sg)), BM, and weighted segmental impedance at frequencies of 5, 20, 50, 100, and 500 kHz. ⋯ Estimations of extracellular water were significantly different throughout the trial, but there were no significant changes in the estimations of the total body water or intracellular water. The results of this study demonstrate the potential use of DSM-BIA as a field measure to assess the hydration status of wrestlers for the purpose of minimal weight certification before the competitive season. When employing DSM-BIA to assess the hydration status, the results indicated that the changes in weighted segmental impedance at the frequencies evaluated (5, 20, 50, 100, and 500 kHz) are sensitive to acute changes in dehydration but lag behind changes in the standard physiological (plasma and urinary) markers of hydration status after a 2-hour rehydration period.
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J Strength Cond Res · Dec 2011
Core stability exercises in individuals with and without chronic nonspecific low back pain.
Marshall, PWM, Desai, I, and Robbins, DW. Core stability exercises in individuals with and without chronic nonspecific low back pain. J Strength Cond Res 25(12): 3404-3411, 2011-The aim of this study was to measure trunk muscle activity during several commonly used exercises in individuals with and without low back pain (LBP). ⋯ The LROM was no different between groups for any exercise. The lack of worsening of symptoms in the LBP group and similar LROM observed between groups suggest that all exercises investigated in this study are of use in rehabilitating LBP patients. The widespread use of abdominal bracing in clinical practice, whether it be for patients with LBP or healthy individuals, may not be justified unless symptoms of spinal instability are identified.
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J Strength Cond Res · Dec 2011
Case ReportsExertional rhabdomyolysis in an adolescent athlete during preseason conditioning: a perfect storm.
Cleary, MA, Sadowski, KA, Lee, SY-C, Miller, GL, and Nichols, AW. Exertional rhabdomyolysis in an adolescent athlete during preseason conditioning: a perfect storm. J Strength Cond Res 25(12): 3506-3513, 2011-The purpose of this brief review is to present a case of a healthy, male adolescent athlete (age = 16 years, body mass = 67.9 kg, height = 165.5 cm) who participated in a 3-day preseason wrestling camp which resulted in hospitalization for exertional rhabdomyolysis. ⋯ The athlete was hospitalized for 6 days where he received intravenous normal saline for rehydration, and his CK levels were assessed daily. Athletic Trainers, personal trainers, physical education teachers, and coaches should be aware that exertional rhabdomyolysis is the most common form of rhabdomyolysis and affects individuals who participate in novel and intense exercise to which they are unaccustomed. Stressful ambient conditions may lead to dehydration and exacerbation of the condition, particularly when the individual is not accustomed to the exercise intensity.
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J Strength Cond Res · Aug 2011
Randomized Controlled TrialComparison of body cooling methods on physiological and perceptual measures of mildly hyperthermic athletes.
Hyperthermia is common among athletes and in a variety of environments. The purpose of this study was to evaluate the effectiveness of cooling methods on core body temperature, heart rate (HR), and perceptual readings in individuals after exercise. Sixteen subjects (age: 24 ± 6 years, height: 182 ± 7 cm, weight: 74.03 ± 9.17 kg, and body fat: 17.08 ± 6.23%) completed 10 exercise sessions in warm conditions (WBGT: 26.64 ± 4.71°C) followed by body cooling by 10 different methods. ⋯ The ESQ scores were significantly (p < 0.006) lower for CWI (1 ± 6), Fan (4 ± 5), and IT (3 ± 8) compared with that for SUN (13 ± 12). In conclusion, when athletes experience mild hyperthermia, CWI, ECCS, and IB resulted in a significantly greater decrease in T(re). These cooling strategies are recommended to decrease T(re) during a brief recovery period between exercise bouts.
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J Strength Cond Res · Aug 2011
Intra and intersession reliability of balance measures during one-leg standing in young adults.
A study was designed to investigate the intra and intersession reliability during 1-leg standing recorded from a computerized balance platform. Thirty-nine healthy young men (n = 17, age range: 20-30 years) and women (n = 22, age range: 21-28 years) performed 3 testing sessions, with the second session 30 minutes (intrasession comparison) and the third session 1 week (intersession comparison) after the initial testing session. Within each testing session, participants completed 3 trials of 1-leg standing with their dominant leg. ⋯ Bland-Altman plots confirmed these findings by showing that only 1 or 2 (4.5-11.8%) of the data points were beyond the 95% CI. Practitioners and clinicians are provided with a posturographic test setup that proved to be reliable. Researchers can use these data to identify the range in which the true value of a subject's score lies and estimate a priori sample sizes.