Estimation of prepractice hydration status of National Collegiate Athletic Association Division I athletes

J Athl Train. Nov-Dec 2009;44(6):624-9. doi: 10.4085/1062-6050-44.6.624.

Abstract

Context: 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.

Design: Cross-sectional, descriptive study.

Setting: University sports team practices.

Patients or other participants: 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.

Intervention(s): One spontaneously voided (spot) urine sample was collected from each participant before his or her team practice and was measured 2 times.

Main outcome measure(s): 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.

Keywords: dehydration; hypohydration; refractometer; sex; sports; urine specific gravity.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Cross-Sectional Studies
  • Dehydration* / diagnosis
  • Dehydration* / etiology
  • Dehydration* / prevention & control
  • Drinking*
  • Female
  • Fluid Therapy
  • Health Behavior*
  • Health Status
  • Humans
  • Male
  • Menstrual Cycle / physiology
  • Refractometry
  • Specific Gravity
  • Sports Medicine
  • Sports* / physiology
  • Surveys and Questionnaires
  • Time Factors
  • United States
  • Universities
  • Urinalysis
  • Water-Electrolyte Balance*
  • Young Adult