Elite Kenyan Endurance Runners are Hydrated Day-To-Day with Ad Libitum Fluid Intake

FUDGE, BARRY W.1,2; EASTON, CHRIS1,2; KINGSMORE, DAVID1,3; KIPLAMAI, FESTUS K.1,4; ONYWERA, VINCENT O.1,4; WESTERTERP, KLAAS R.1,5; KAYSER, BENGT1,6; NOAKES, TIMOTHY D.1,7; PITSILADIS, YANNIS P.1,2

Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e318169cdda
APPLIED SCIENCES: Physical Fitness and Performance
Abstract

Previous studies of elite Kenyan endurance runners reported that athletes did not consume liquids before or during training and infrequently consumed modest amounts of liquids after training that contributed to low daily fluid intake.

Purpose: To assess hydration status of elite Kenyan endurance runners during an important training period.

Methods: Hydration status was monitored in fourteen elite Kenyan endurance runners over a 5-d training period 1 wk prior to the Kenyan national trials for the 2005 IAAF Athletics World Championships by measuring body mass, urine osmolality, total body water, and daily fluid intake. Dietary sodium (Na) intake was estimated using a 5-d nutritional diary and biochemical analysis, whilst [Na] was determined in urine and sweat. Intestinal temperature was monitored continuously during training sessions.

Results: Daily fluid intake was consistent with previous observations. There was a significant body mass loss during the morning, interval, and afternoon training sessions (P < 0.05). Nevertheless, mean total body water and pretraining body mass were well maintained day-to-day throughout the 5-d recording period (P = 0.194 and P = 0.302, respectively). Furthermore, there was no significant difference between the osmolality of the morning urine sample and the evening sample (P = 0.685). Mean Na intake was not significantly different to Na loss in sweat and urine (P = 0.975). No athlete showed signs or symptoms of heat strain at any time.

Conclusions: These results demonstrate that elite Kenyan endurance runners remain well hydrated day-to-day with an ad libitum fluid intake; a pattern and volume of fluid intake that is consistent with previous observations of elite Kenyan endurance runners.

Author Information

1International Centre for East African Running Science (ICEARS); 2Institute of Biomedical & Life Sciences (IBLS), University of Glasgow, Glasgow, UNITED KINGDOM; 3Department of Surgery, Gartnavel General Hospital, Glasgow, UNITED KINGDOM; 4Department of Exercise and Sports Science, Kenyatta University, Nairobi, KENYA; 5Department of Human Biology, Maastricht University, Maastricht, THE NETHERLANDS; 6School of Physical Education and Sports, Institute of Movement Sciences and Sports Medicine, Faculty of Medicine, University of Geneva, SWITZERLAND; and 7UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town and Sports Science Institute of South Africa, Newlands, SOUTH AFRICA

Address for correspondence: Dr YP Pitsiladis, International Centre for East African Running Science (ICEARS), Institute of Biomedical & Life Sciences, West Medical Building, University of Glasgow, Glasgow, G12 8QQ, UK; E-mail: Y.Pitsiladis@bio.gla.ac.uk.

Submitted for publication September 2007.

Accepted for publication January 2008.

©2008The American College of Sports Medicine