Biomedical subjects

Jude C Sullivan

Publications and source records attributed to Jude C Sullivan.

7 recordsLinked to original sources

PubMed2005

Is leg-to-leg BIA valid for predicting minimum weight in wrestlers?

BACKGROUND: The National Collegiate Athletic Association (NCAA) and several state associations require prediction of minimum weight (MW) for collegiate and high school wrestlers. The rule requires assessment of body composition before the competitive season to minimize unhealthy weight-loss practices. Leg-to-leg bioelectrical impedance analysis (BIA) has been suggested for use with wrestlers. PURPOSE: To evaluate leg-to-leg BIA against a four-component (4C) criterion to determine whether leg-to-leg BIA predicted MW within acceptable limits for the sport of wrestling. METHODS: Criterion MW was calculated by the 4C equation of Lohman (19) using independent measurement of body density (BD) by hydrostatic weighing, bone mineral content (BMC) by dual x-ray absorptiometry (DXA), and total body water (TBW) by deuterium dilution. Subjects were 57 wrestlers (mean +/- SD; age = 19.7 +/- 1.3 yr, height = 176.6 +/- 7.3 cm, weight = 77.7 +/- 12.4 kg). Hydration was confirmed by the NCAA guidelines. Accuracy, precision, and systematic bias were examined. RESULTS: Comparable mean values (72.2 +/- 9.7 vs 72.2 +/- 10.3 kg), a high correlation (r = 0.94), and a regression line similar to the line of identity were found between BIA and 4C. However, large individual differences and systematic bias were seen across the range of MW. BIA predicted MW within 3.5 kg 68% of the time and within 7.0 kg 95% of the time. MW residuals ranged from -10.4 kg to +6.9 kg. When using 2.0 kg as an acceptable cutoff for error, only 40% of the BIA values were within 2.0 kg of the criterion. CONCLUSION: Large individual variation was seen, and, by definition, the precision was poor when estimating MW for individuals. In practical terms, the prediction error may span multiple weight classes, thus making leg-to-leg BIA unacceptable for prediction of MW in this sample under the conditions of the study.

Absorptiometry, Photon↗

PubMed2004

The effect of dehydration on wrestling minimum weight assessment.

UNLABELLED: Given that some wrestlers arrive for minimum weight (MW) testing in a dehydrated condition, it is important to understand the effects of dehydration on MW assessment methods. PURPOSE: To determine the effect of dehydration on the assessment of MW by three-site skinfolds with the Lohman formula (SF), leg-to-leg bioelectrical impedance analysis (BIA), and multifrequency bioelectrical impedance spectroscopy (BIS) compared with a four-component (4C) criterion. METHODS: Twenty-two male collegiate wrestlers (mean +/- SD, age: 19.9 +/- 1.4 yr, height: 174.0 +/- 6.8 cm, body mass: 77.4 +/- 9.1 kg) had their body composition assessed by the 4C criterion, hydrostatic weighing (HW), SF, BIA, and BIS in euhydration (EUH) and dehydration (DEH). Subjects dehydrated 2-5% of body weight through fluid restriction and exercise in a hot environment. RESULTS: In EUH, the total error (TE) for HW (1.75 kg) and SF (2.15 kg) were not significantly different, but the TE for HW and SF methods were significantly lower than the TE for both BIS (3.68 kg) and BIA (3.77 kg). In DEH, SF, BIA, and BIS methods had a TE approaching or exceeding 4 kg (8.8 lb). Dehydration increased the TE for SF and BIA through an artificial lowering of body weight and for BIS by an increased error in intracellular water prediction. CONCLUSION: Acute thermal dehydration violates assumptions necessary for the accurate and precise prediction of MW by SF, leg-to-leg BIA, and multifrequency BIS.

Adolescent↗

PubMed2004

Hydration testing in collegiate wrestlers undergoing hypertonic dehydration.

UNLABELLED: Because dehydration (DEH) violates assumptions used in the assessment of body composition, hydration testing has become an integral part of minimal weight (MW) assessment. PURPOSE: To determine the accuracy of hydration tests for the detection and quantification of hypertonic DEH. METHODS: Twenty-five male collegiate wrestlers (mean +/- SD, age: 20.0 +/- 1.4 yr, height: 175.0 +/- 7.1 cm, body mass: 81.7 +/- 15.3 kg) had their hydration assessed under well-controlled conditions of euhydration (EUH) and DEH. The DEH phase occurred on the same day as EUH, after subjects acutely dehydrated 2-6% of body weight through fluid/food restriction and exercise in a hot environment. RESULTS: All hydration tests except plasma potassium significantly increased from EUH to DEH, and meaningful cutoff values could be established for most tests. Cutoff values for urine tests were 586 mOsm.L(-1) for osmolality and 71 mEq.L(-1) for potassium. Plasma cutoff values were 293 mOsm.L(-1) for osmolality, 140 mEq.L(-1) for sodium, 103 mEq.L(-1) for chloride, and 3.5 pg.mL(-1) for arginine vasopressin. For ratio tests, a urine:plasma osmolality of 2.06 and an extracellular:intracellular water of 0.533 measured by the bioelectrical impedance spectroscopy were cutoff values. For urine specific gravity, a cutoff value of 1.020 g.mL(-1) had a sensitivity and specificity of 96% each for the automated harmonic oscillation technique and 87% and 91% (respectively) for the dipstick technique. Protein (by dipstick) was detected in 5% of subjects in EUH, and 100% of subjects in DEH. Correlations between hydration tests and dehydration were only low to moderate. CONCLUSION: This study supports a specific gravity cutoff of 1.020 g.mL(-1) for the identification of hypertonic DEH. Future research should test the cutoff values established in this study and explore the relationship between DEH and urine protein.

Adult↗

PubMed2004

Minimum weight prediction methods cross-validated by the four-component model.

UNLABELLED: The National Collegiate Athletic Association (NCAA) requires prediction of minimum weight (MW) for collegiate wrestlers. The rule was implemented to minimize unhealthy weight loss practices and requires assessment of body composition before the competitive season. PURPOSE: This study cross-validated the body composition methods of dual energy x-ray absorptiometry (DXA), leg-to-leg bioelectrical impedance analysis (BIA), hydrostatic weighing (HW), and skinfolds (SF) for predicting MW using a four-component criterion (4C). METHODS: Criterion MW was calculated by the 4C model using independent measurement of body density (BD), bone mineral content (BMC), and total body water (TBW). Subjects were 53 Division I athletes from the University of Wisconsin (mean +/- SD; age = 19.7 +/- 1.3 yr, height = 176.2 +/- 7.4 cm, weight = 75.6 +/- 8.9 kg). Accuracy, precision, and systematic bias were examined in the predictions. RESULTS: There were no significant differences in mean MW from HW (70.5 +/- 7.3 kg, P = 0.57), SF (70.5 +/- 7.2 kg, P = 0.29) BIA (70.6 +/- 7.6 kg, P = 0.39), DXA (70.3 +/- 7.5, P = 0.97), and the 4C criterion (70.3 +/- 7.4 kg). The regression for the relationships between 4C and HW (y = 0.994 x HW + 0.077 kg), 4C and SF (y = 1.003 x SF-0.437 kg), 4C and DXA (y = 0.942 x DXA + 4.034 kg), and 4C and BIA (y = 0.896 x BIA + 6.987 kg) did not significantly deviate from the line of identity. Pure error (PE) values ranged from 1.34 kg for HW to 3.08 kg for BIA. CONCLUSION: Comparable means, high correlations, regression lines that did not significantly deviate from the line of identity, and no systematic bias were found. However, the methods differed widely in precision. The best precision, based on SEE and PE values, were seen in the HW and SF methods. In conclusion, this rigorous four-component cross-validation study supports the NCAA methods as the most accurate and precise MW prediction methods in this sample.

Absorptiometry, Photon↗

PubMed2003

Multicomponent cross-validation of minimum weight predictions for college wrestlers.

UNLABELLED: In 1998, the National Collegiate Athletic Association (NCAA) adopted a rule requiring that skinfolds (SF) or hydrostatic weighing (HW) be used to estimate minimum weight (MW) in college wrestlers. PURPOSE: To cross-validate the NCAA methods for estimation of MW using a multicomponent criterion (4C). METHODS: Criterion MW was calculated from body density (BD), bone mineral content (BMC), and total body water (TBW) using the 4C equation of Lohman (1992). BMC was measured by dual energy x-ray absorptiometry (DXA), TBW by deuterium dilution, and BD by HW. Subjects were Division I athletes from the University of Wisconsin (mean +/- SD; N = 33, age = 19.5 +/- 1.3 yr, height = 177.3 +/- 7.8 cm, weight = 74.2 +/- 9.3kg). RESULTS: There was no significant difference between mean MW from HW (69.6 +/- 8.5 kg) and SF (70.1 +/- 8.3 kg) ( P = 0.113), and between mean MW from HW (69.6 +/- 8.5 kg) and 4C (69.5 +/- 8.6 kg) ( P = 0.46). A clinically small, yet significant difference was seen when comparing mean MW from SF to 4C ( P = 0.013). The regression for the relationship between 4C and HW (y = 0.994 x HW + 0.294 kg, R2 = 0.985) and 4C and SF (y = 1.019 x SF - 1.885 kg, R2 = 0.979) did not significantly deviate from the line of identity. Pure error (PE) values of 1.04 kg and 1.35 kg were found for HW and SF, respectively. The difference between the methods was plotted as a function of the 4C criterion. The regression line for HW and 4C (y = -0.009x + 0.743, r = -0.07, P = 0.69) and SF and 4C (y = -0.038x + 3.259, r = -0.27, P = 0.13) suggest that no systematic differences in the prediction were associated with the size of the criterion. CONCLUSION: These data support the NCAA methods of HW and SF to predict MW when cross-validated using a 4C criterion in this sample.

Absorptiometry, Photon↗

PubMed2002

Cross-validation of the NCAA method to predict body fat for minimum weight in collegiate wrestlers.

OBJECTIVE: In 1998, the National Collegiate Athletic Association (NCAA) adopted a new rule that required minimum weight testing for collegiate wrestlers. The objective of the study was to cross-validate the method used by the NCAA to estimate minimum weight in collegiate wrestlers. DESIGN: The NCAA skinfold equation was cross-validated against a criterion value from hydrostatic weighing (HW). SETTING The subjects were tested at the Universities of Wisconsin and Iowa. SUBJECTS: A sample of 93 college wrestlers from the Universities of Wisconsin and Iowa (mean +/- SD; age = 20.20 +/- 1.67 years, height = 171.98 +/- 6.63 cm, weight = 74.44 +/- 11.48 kg) were studied. OUTCOME MEASURES: Cross-validation included analysis of the standard error of estimate (SEE), total error (TE), and residual plots. RESULTS: The mean body fat from the NCAA prediction (10.61 +/- 3.58%) was not significantly different than HW (9.70 +/- 3.95%). The SEE was low (2.32%), and the TE was low (2.49%). The difference in methods was related to the size of the HW value. The residual plot (y = -0.26x + 3.45, R(2) = 0.198) suggests that fat is overestimated in the leaner wrestlers and underestimated in fatter wrestlers. CONCLUSION: The authors found the NCAA method to be a valid predictor of body fat in this sample of 93 collegiate wrestlers under the conditions of the study. Although some bias was seen across the range of fatness, these data support the NCAA method to estimate body fat in college wrestlers for establishment of minimum weight.

Adipose Tissue↗

PubMed2002

Creatine supplementation in Wisconsin high school athletes.

BACKGROUND: Creatine is a nutritional supplement used to enhance athletic performance in collegiate and professional athletes. There is increasing evidence that high school athletes are using creatine as well. The objective of this study was to describe patterns of creatine supplementation as well as the behaviors and beliefs associated with creatine use in high school athletes. METHODS: 4011 high school student-athletes from 37 public high schools in Wisconsin took part in a cross-sectional, multi-site, anonymous, descriptive survey. Measurements included self-reported patterns of creatine use. RESULTS: 16.7% of the athletes (25.3% males, 3.9% females) reported using creatine. Creatine use was lowest in the 9th grade (8.4%) and highest in the 12th grade (24.6%). The percentage of participants in each sport who used creatine varied considerably from 1.3% (female cross country) to 30.1% (football). Increased strength was the most likely perceived benefit of creatine supplementation, while dehydration was cited most often as a perceived risk of creatine use. Users were encouraged to take creatine most often by their friends while their parents discouraged its use. CONCLUSION: Despite the lack of research regarding the efficacy or safety of creatine supplementation in high school athletes, creatine was used by 25% of males and 4% of female high school athletes in Wisconsin. High school athletes who use creatine may not be aware of the risks and benefits associated with creatine supplementation. Primary care providers and sports medicine professionals need to educate athletes, coaches and parents about the creatine use as a performance enhancing supplement.

Adolescent↗