Relationship Between Changes in Upon-Waking Urinary Indices of Hydration Status and Body Mass in Adolescent Singaporean Athletes

Click name to view affiliation

Chin Han Lew
Search for other papers by Chin Han Lew in
Current site
Google Scholar
PubMed
Close
,
Gary Slater
Search for other papers by Gary Slater in
Current site
Google Scholar
PubMed
Close
,
Gobinathan Nair
Search for other papers by Gobinathan Nair in
Current site
Google Scholar
PubMed
Close
, and
Michelle Miller
Search for other papers by Michelle Miller in
Current site
Google Scholar
PubMed
Close
Restricted access

This study investigated the relationship between changes in upon-waking body mass (BM) and changes in urine specific gravity (Usg) and urine color (Ucol) from 1 day to the next. Throughout the 5-day investigation, healthy adolescent Singaporean athletes (n = 66) had their upon-waking, bladder-voided BM measured. A small aliquot of the first bladder void each day was collected and analyzed for Usg and Ucol, the latter by both an investigator (IUcol) and individual participants (SUcol). Results revealed a significant inverse relationship between changes in BM and changes in Usg (p = .003) and Ucol (p = .001). On average, Usg and Ucol changed by ~0.003 units and ~1 color (across a 9-unit scale), respectively, with every 1% change in BM from 1 day to the next. There was a stronger relationship between Usg and IUcol (r = .82, p < .001) than between Usg and SUcol (r = .60, p < .001). These results suggest that the degree of fluid deficit may be predicted from the Usg measurements among moderately hypohydrated athletes. In addition, training athletes to interpret and use the Ucol chart is recommended.

Lew is with the Nutrition Dept., Adult Health Division, Health Promotion Board, Singapore. Slater is with High Performance Group, Singapore Sports Council, Singapore. Nair is with the Sports Science Academy, Singapore Sports School, Singapore. Miller is with the Dept. of Nutrition and Dietetics, Flinders University, Bedford Park, Australia.

  • Collapse
  • Expand