Urine Specific Gravity as a Practical Marker for Identifying Suboptimal Fluid Intake of Runners ∼12-hr Postexercise

in International Journal of Sport Nutrition and Exercise Metabolism
Restricted access

Purchase article

USD  $24.95

Student 1 year subscription

USD  $87.00

1 year subscription

USD  $116.00

Student 2 year subscription

USD  $165.00

2 year subscription

USD  $215.00

The legitimacy of urine specific gravity (USG) as a stand-alone measure to detect hydration status has recently been challenged. As an alternative to hydration status, the purpose of this study was to determine the diagnostic capability of using the traditional USG marker of >1.020 to detect insufficient recovery fluid consumption with consideration for moderate versus high sweat losses (2.00–2.99 or >3% body mass, respectively). Adequate recovery fluid intake was operationally defined as ≥100% beverage fluid intake plus food water from one or two meals and a snack. Runners (n = 59) provided 132 samples from five previous investigations in which USG was assessed 10–14 hr after 60–90 min runs in temperate-to-hot environments. Samples were collected after a meal (n = 58) and after waking (n = 74). When sweat losses exceeded 3% body mass (n = 60), the relationship between fluid replacement percentage and USG increased from r = −.55 to −.70. Correct diagnostic decision improved from 66.6 to 83.3%, and receiver operating characteristic area under the curve increased the diagnostic accuracy score from 0.76 to approaching excellent (0.86). Artifacts of significant prerun hyperhydration (eight of 15 samples has USG <1.005) may explain false positive diagnoses, while almost all (84%) cases of false positives were found when sweat losses were <3.0% of body mass. Evidence from this study suggests that euhydrated runners experiencing significant sweat losses who fail to reach adequate recovery fluid intake levels can be identified by USG irrespective of acute meal and fluid intake ∼12-hr postrun.

O’Neal is with the University of North Alabama, Florence, AL. Johnson is with Middle Tennessee State University, Murfreesboro, TN. Davis is with Kentucky Wesleyan College, Owensboro, KY. Pribyslavska is with Arkansas State University, Jonesboro, AR. Stevenson-Wilcoxson is with the Harding University, Searcy, AR.

Address author correspondence to Eric Kyle O’Neal at eoneal1@una.edu.
  • Armstrong, L.E. (2007). Assessing hydration status: The elusive gold standard. Journal of the American College of Nutrition, 26(suppl. 5), 575S584S. PubMed ID: 17921468 doi:10.1080/07315724.2007.10719661

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Armstrong, L.E., Pumerantz, A.C., Fiala, K.A., Roti, M.W., Kavouras, S.A., Casa, D.J., & Maresh, C.M. (2010). Human hydration indices: Acute and longitudinal reference values. International Journal of Sport Nutrition and Exercise Metabolism, 20(2), 145153. PubMed ID: 20479488 doi:10.1123/ijsnem.20.2.145

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Beis, L.Y., Willkomm, L., Ross, R., Bekele, Z., Wolde, B., Fudge, B., & Pitsiladis, Y.P. (2011). Food and macronutrient intake of elite Ethiopian distance runners. Journal of the International Society of Sports Nutrition, 8, 7. PubMed ID: 21595961 doi:10.1186/1550-2783-8-7

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Beis, L.Y., Wright-Whyte, M., Fudge, B., Noakes, T., & Pitsiladis, Y.P. (2012). Drinking behaviors of elite male runners during marathon competition. Clinical Journal of Sport Medicine, 22(3), 254261. PubMed ID: 22450589 doi:10.1097/JSM.0b013e31824a55d7

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Beltrami, F.G., Hew-Butler, T., & Noakes, T.D. (2008). Drinking policies and exercise-associated hyponatraemia: Is anyone still promoting overdrinking? British Journal of Sports Medicine, 42(10), 796501. PubMed ID: 18400876 doi:10.1136/bjsm.2008.047944

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Byrne, C., Lee, J.K., Chew, S.A., Lim, C.L., & Tan, E.Y. (2006). Continuous thermoregulatory responses to mass-participation distance running in heat. Medicine & Science in Sports & Exercise, 38(5), 803810. PubMed ID: 16672830 doi:10.1249/01.mss.0000218134.74238.6a

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Casa, D.J., Armstrong, L.E., Hillman, S.K., Montain, S.J., Reiff, R.V., Rich, B.S., . . . Stone, J.A. (2000). National Athletic Trainers’ Association position statement: Fluid replacement for athletes. Journal of Athletic Training, 35(2), 212224. PubMed ID: 16558633

    • Search Google Scholar
    • Export Citation
  • Casa, D.J., Clarkson, P.M., & Roberts, W.O. (2005). American College of Sports Medicine roundtable on hydration and physical activity: Consensus statements. Current Sports Medicine Reports, 4(3), 115127. PubMed ID: 15907263 doi:10.1097/01.CSMR.0000306194.67241.76

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Casa, D.J., Stearns, R.L., Lopez, R.M., Ganio, M.S., McDermott, B.P., Walker Yeargin, S., . . . Maresh, C.M. (2010). Influence of hydration on physiological function and performance during trail running in the heat. Journal of Athletic Training, 45(2), 147156. PubMed ID: 20210618 doi:10.4085/1062-6050-45.2.147

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., Carter, R., 3rd, Montain, S.J., & Sawka, M.N. (2004). Daily body mass variability and stability in active men undergoing exercise-heat stress. International Journal of Sport Nutrition and Exercise Metabolism, 14(5), 532540. PubMed ID: 15673099 doi:10.1123/ijsnem.14.5.532

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., Carter, R., 3rd, & Sawka, M.N. (2003). Fluid balance and endurance exercise performance. Current Sports Medicine Reports, 2(4), 202208. PubMed ID: 12834575 doi:10.1249/00149619-200308000-00006

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., & Kenefick, R.W. (2014). Dehydration: Physiology, assessment, and performance effects. Comprehensive Physiology, 4(1), 257285. PubMed ID: 24692140 doi:10.1002/cphy.c130017

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., Kenefick, R.W., Charkoudian, N., & Sawka, M.N. (2013). Physiologic basis for understanding quantitative dehydration assessment. The American Journal of Clinical Nutrition, 97(3), 455462. PubMed ID: 23343973 doi:10.3945/ajcn.112.044172

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., Kenefick, R.W., & Zambraski, E.J. (2015). Spot urine concentrations should not be used for hydration assessment: A methodology review. International Journal of Sport Nutrition and Exercise Metabolism, 25(3), 293297. PubMed ID: 25386829 doi:10.1123/ijsnem.2014-0138

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cheuvront, S.N., Montain, S.J., & Sawka, M.N. (2007). Fluid replacement and performance during the marathon. Sports Medicine, 37(4–5), 353357. PubMed ID: 17465606 doi:10.2165/00007256-200737040-00020

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Convertino, V.A., Armstrong, L.E., Coyle, E.F., Mack, G.W., Sawka, M.N., Senay, L.C., Jr., & Sherman, W.M. (1996). American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 28(1), ivii. PubMed ID: 9303999 doi:10.1097/00005768-199610000-00045

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davis, B.A., O’Neal, E.K., Johnson, S.L., & Farley, R.S. (2016). Ad libitum fluid replacement threshold evidenced in runners at 12-h post-run in hot environment. Medicine & Science in Sports & Exercise, 48(5, suppl. 1), 166. PubMed ID: 27584252 doi:10.1249/01.mss.0000485501.14665.13

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Davis, B.A., Thigpen, L.K., Hornsby, J.H., Green, J.M., Coates, T.E., & O’Neal, E.K. (2014). Hydration kinetics and 10-km outdoor running performance following 75% versus 150% between bout fluid replacement. European Journal of Sport Science, 14(7), 703710. PubMed ID: 24697790 doi:10.1080/17461391.2014.894578

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Evans, G.H., James, L.J., Shirreffs, S.M., & Maughan, R.J. (2017). Optimizing the restoration and maintenance of fluid balance after exercise-induced dehydration. Journal of Applied Physiology (1985), 122(4), 945951. PubMed ID: 28126906 doi:10.1152/japplphysiol.00745.2016

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fudge, B.W., Easton, C., Kingsmore, D., Kiplamai, F.K., Onywera, V.O., Westerterp, K.R., . . . Pitsiladis, Y.P. (2008). Elite Kenyan endurance runners are hydrated day-to-day with ad libitum fluid intake. Medicine & Science in Sports & Exercise, 40(6), 11711179. PubMed ID: 18460986 doi:10.1249/MSS.0b013e318169cdda

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hew-Butler, T., Almond, C., Ayus, J.C., Dugas, J., Meeuwisse, W., Noakes, T., . . . Exercise-Associated Hyponatremia Consensus Panel. (2005). Consensus statement of the 1st International Exercise-Associated Hyponatremia Consensus Development Conference, Cape Town, South Africa 2005. Clinical Journal of Sport Medicine, 15(4), 208213. PubMed ID: 16003032

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kavouras, S.A., Arnaoutis, G., Makrillos, M., Garagouni, C., Nikolaou, E., Chira, O., . . . Sidossis, L.S. (2012). Educational intervention on water intake improves hydration status and enhances exercise performance in athletic youth. Scandinavian Journal of Medicine & Science in Sports, 22(5), 684689. PubMed ID: 21410548 doi:10.1111/j.1600-0838.2011.01296.x

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, J.K., Nio, A.Q., Lim, C.L., Teo, E.Y., & Byrne, C. (2010). Thermoregulation, pacing and fluid balance during mass participation distance running in a warm and humid environment. European Journal of Applied Physiology, 109(5), 887898. PubMed ID: 20237797 doi:10.1007/s00p421-010-1405-y

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Maughan, R.J., & Shirreffs, S.M. (2008). Development of individual hydration strategies for athletes. International Journal of Sport Nutrition and Exercise Metabolism, 18(5), 457472. PubMed ID: 19033609 doi:10.1123/ijsnem.18.5.457

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McDermott, B.P., Anderson, S.A., Armstrong, L.E., Casa, D.J., Cheuvront, S.N., Cooper, L., . . . Roberts, W.O. (2017). National athletic trainers’ association position statement: Fluid replacement for the physically active. Journal of Athletic Training, 52(9), 877895. PubMed ID: 28985128 doi:10.4085/1062-6050-52.9.02

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Neal, E.K., Caufield, C.R., Lowe, J.B., Stevenson, M.C., Davis, B.A., & Thigpen, L.K. (2014). 24-h fluid kinetics and perception of sweat losses following a 1-h run in a temperate environment. Nutrients, 6(1), 3749. PubMed ID: 24451307 doi:10.3390/nu6010037

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Neal, E.K., Davis, B.A., Thigpen, L.K., Caufield, C.R., Horton, A.D., & McIntosh, J.R. (2012). Runners greatly underestimate sweat losses before and after a 1-hr summer run. International Journal of Sport Nutrition and Exercise Metabolism, 22(5), 353362. PubMed ID: 23011653 doi:10.1123/ijsnem.22.5.353

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Neal, E.K., Wingo, J.E., Richardson, M.T., Leeper, J.D., Neggers, Y.H., & Bishop, P.A. (2011). Half-marathon and full-marathon runners’ hydration practices and perceptions. Journal of Athletic Training, 46(6), 581591. PubMed ID: 22488182 doi:10.4085/1062-6050-46.6.581

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Oppliger, R.A., Magnes, S.A., Popowski, L.A., & Gisolfi, C.V. (2005). Accuracy of urine specific gravity and osmolality as indicators of hydration status. International Journal of Sport Nutrition and Exercise Metabolism, 15(3), 236251. PubMed ID: 16131695 doi:10.1123/ijsnem.15.3.236

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Passe, D., Horn, M., Stofan, J., Horswill, C., & Murray, R. (2007). Voluntary dehydration in runners despite favorable conditions for fluid intake. International Journal of Sport Nutrition and Exercise Metabolism, 17(3), 284295. PubMed ID: 17693689 doi:10.1123/ijsnem.17.3.284

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Popowski, L.A., Oppliger, R.A., Patrick Lambert, G., Johnson, R.F., Kim Johnson, A., & Gisolf, C.V. (2001). Blood and urinary measures of hydration status during progressive acute dehydration. Medicine & Science in Sports & Exercise, 33(5), 747753. PubMed ID: 11323543 doi:10.1097/00005768-200105000-00011

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sawka, M.N., Burke, L.M., Eichner, E.R., Maughan, R.J., Montain, S.J., & Stachenfeld, N.S. (2007). American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 39(2), 377390. PubMed ID: 17277604 doi:10.1249/mss.0b013e31802ca597

    • Search Google Scholar
    • Export Citation
  • Shirreffs, S.M., Armstrong, L.E., & Cheuvront, S.N. (2004). Fluid and electrolyte needs for preparation and recovery from training and competition. Journal of Sports Sciences, 22(1), 5763. PubMed ID: 14971433 doi:10.1080/0264041031000140572

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sobana, R.M., & Many, J.M. (2014). Effect of hydration education on college athlete’s hydration status and KAP. International Journal of Science and Research, 3(7), 16541658.

    • Search Google Scholar
    • Export Citation
  • Stearns, R.L., Casa, D.J., Lopez, R.M., McDermott, B.P., Ganio, M.S., Decher, N.R., . . . Maresh, C.M. (2009). Influence of hydration status on pacing during trail running in the heat. Journal of Strength & Conditioning Research, 23(9), 25332541. PubMed ID: 19675477 doi:10.1519/JSC.0b013e3181b73c3f

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilcoxson, M.C., Johnson, S.L., Pribyslavska, V., Green, J.M., & O’Neal, E.K. (2017). Fluid retention and utility of practical hydration markers to detect three levels of recovery fluid intake in male runners. International Journal of Sport Nutrition and Exercise Metabolism, 27(2), 178185. PubMed ID: 27710148 doi:10.1123/ijsnem.2015-0362

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Winger, J.M., Dugas, J.P., & Dugas, L.R. (2011). Beliefs about hydration and physiology drive drinking behaviours in runners. British Journal of Sports Medicine, 45(8), 646649. PubMed ID: 20876587 doi:10.1136/bjsm.2010.075275

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yates, B.A., Ellis, L.A., Butts, C.L., McDermott, B.P., Williamson, K.H., & Armstrong, L.E. (2017). Factors associated with pre-event hydration status and drinking behavior of middle-aged cyclists. The Journal of Nutrition, Health & Aging. 22(3):335340. PubMed ID: 29484346 doi:10.1007/s12603-017-0927-y

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 212 212 14
Full Text Views 15 15 3
PDF Downloads 13 13 1