Urinalysis has been shown to be the most valid and reliable method for determining moderate changes in fluid balance. This test involves collecting a sample of urine, and comparing the color to a color chart.
equipment required: Urine specimen containers, ice bucket for storage and ice, color rating chart, gloves, clip boards, recording sheet, pen.
procedure: The first part of the urine stream is discarded, then a small sample of urine is collected into a clear container. Measurement may be done immediately, or the specimen can be stored for later analysis. The sample is usually collected first thing in the morning. It may also be of interest to collect samples prior to or post-exercise, though there may be a time delay for the effect of dehydration to show in the urine color.
interpretation: The sample should be held up in front of a white background, in good light, and the color compared to a standard color chart. The lower the number, the better the result. A urine color rating of 1, 2 or 3 is considered to be well-hydrated (Armstrong, 2000). Based on these results, changes in fluid intake can be made.
- Certain medicines and vitamins may cause the color of the urine to change. If any of these have been taken, this test is unreliable.
- The colors your see for a urine color chart on the screen, or when you print an image out, may appear different to the original chart. Therefore colors should only be used as a guide. If more accurate comparison is required, please go to an original chart with accurate colors.
Comments: There is a minimal difference in the accuracy of the related measures of urine specific gravity, urine osmolarity, and urine color (Armstrong et al. 1998).
- Armstrong, L.E., Maresh, C.M., Castellani, J.W., Bereron, M.F., Kenefick, R.W., LaGassee, K.E., and Riebe, D. (1994). "Urinary Indices of Hydration Status.", Int. J. Sport Nutr., 4, 265-279.
- Armstrong, L.E., Soto, J.A., Hacker, F.T., Casa, D.J., Kavouras, S.A., Maresh, C.M. (1998). "Urinary indices during dehydration, exercise, and rehydration." Int. J. Sport Nutr. 8: 345-355.
- Armstrong, L.E. (2000). Performing in Extreme Environments, Human Kinetics, Champaign, IL.
- Urine specific gravity — using a refractometer to measure the density of urine.
- Sweat Collection for Analysis — collecting sweat using patches to measure electrolyte composition.
- Sweat Loss Measurement — whole body fluid loss measurement using body weight changes.
- Sweat Monitoring — skin monitors to measure sweat rate and composition.
- Sweat Rate using patches — measurement of site-specific sweating rate.
- About testing hydration
- Hydration for sport: a collection of articles
- Sweat Analysis Methods
- Discussion of methods of measuring hydration
- Drug Testing
- Urinalysis health testing