title: Estimation of prepractice hydration status of National Collegiate Athletic Association Division I athletes.
abstract: BACKGROUND
  To our knowledge, no one has compared the prepractice hydration status of male and female National Collegiate Athletic Association (NCAA) Division I athletes or has studied the effects of the menstrual cycle phase on women's prepractice hydration status.
  
  
  OBJECTIVE
  To report prepractice hydration status of collegiate athletes and determine the factors that might influence that status.
  
  
  METHODS
  Cross-sectional, descriptive study.
  
  
  METHODS
  University sports team practices.
  
  
  METHODS
  Participants included 138 male and 125 female athletes (age = 19.9 + or - 1.3 years, height = 165.8 + or - 42.9 cm, mass = 77.4 + or - 17.5 kg) from an NCAA Division I New England university.
  
  
  METHODS
  One spontaneously voided (spot) urine sample was collected from each participant before his or her team practice and was measured 2 times.
  
  
  METHODS
  A refractometer was used to analyze the amount of light that passed through a small drop of urine and assess urine specific gravity. Fluid intake and menstrual history for women were also collected. Three hydration-status groups were defined based on the American College of Sports Medicine and National Athletic Trainers' Association criteria: (1) euhydrated, which was urine specific gravity less than 1.020; (2) hypohydrated, from 1.020 to 1.029; and (3) significantly hypohydrated, equal to or more than 1.030.
  
  
  RESULTS
  Thirteen percent of student-athletes appeared significantly hypohydrated, with a mean urine specific gravity of 1.031 + or - 0.002 (chi(2) = 12.12, P < .05); 53% appeared hypohydrated, with a mean urine specific gravity of 1.024 + or - 0.003 (chi(2) = 12.12, P < .05); and 34% appeared euhydrated, with a mean urine specific gravity of 1.012 + or - 0.005 (chi(2) = 0.03, P > .05). A greater percentage of men (47%) than women (28%) were hypohydrated (chi(2) = 8.33, P < .05). In women, no difference was evident between the luteal and follicular phases of their menstrual cycles (chi(2) = 0.02, P > .05).
  
  
  CONCLUSIONS
  Before activity, athletes were hypohydrated at different levels. A greater percentage of men than women were hypohydrated. Menstrual cycle phase did not appear to affect hydration in women.
authors.affiliation: University of Pennsylvania, Division of Biobehavioral and Health Sciences, School of Nursing, Claire M. Fagin Hall, 418 Curie Boulevard, Philadelphia, PA 19104-4217, USA. svolpe@nursing.upenn.edu
authors.forename: Stella L
authors.initials: SL
authors.lastname: Volpe
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Poule
authors.forename: Erica G
authors.initials: EG
authors.lastname: Bland
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D003681:Dehydration / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D004326:Drinking; D005260:Female; D005440:Fluid Therapy; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology; D012031:Refractometry; D013046:Specific Gravity; D013177:Sports / Q000502:physiology; D013178:Sports Medicine; D011795:Surveys and Questionnaires; D013997:Time Factors; D014481:United States; D014495:Universities; D016482:Urinalysis; D014882:Water-Electrolyte Balance; D055815:Young Adult