Thursday-Abstracts

Official Journal of the American College of Sports Medicine
CONCLusION: Caffeine enhanced triathlon performance, but the effect was not
as pronounced as seen in previous laboratory trials. Caffeine supplementation taken
45-60 minutes before an Olympic-distance triathlon exerted the greatest effect on
performance in the swimming section of the triathlon, as well as on the overall time to
complete the triathlon, in the whole subject group.
1110 Board #55 May 30, 8:00 AM - 9:30 AM
high but not Low Caffeine Ingestion augments Fluid and
Electrolyte Excretion at rest
Stavros A. Kavouras, FACSM1 , Costas N. Bardis2 , Petros
Grigorakis2 , Georgia Georgiou2 , Anna Gavrieli2 , Mary
Yannakoulia2 . 1University of Arkansas, Human Performance
Lab, Fayetteville, AR. 2Harokopio University, Athens, Greece.
Supported by s.a. Kavouras: Consulting Fee; Gatorade Sports Science
Insitute.
It is documented that at rest, large doses of caffeine have diuretic effect and in turn
may lead to hypohydration. However, the acute effect of smaller caffeine doses on
urine excretion is less clear.
PurPOsE: The aim of the present investigation was to examine the acute effect of
coffee with low (3 mg/kg; L-CAF) or high (6 mg/kg ; H-CAF) caffeine content on fluid
and electrolyte urinary excretion in habitual coffee drinkers at rest.
METhOds: Twenty-five healthy adult males (age: 28±5 y, body mass index: 28±5,
mass: 84.6±7.7 kg, height: 1.79±0.01 m) consumed 200 ml of water (W) or coffee
with 3 mg/kg caffeine (L-CAF) on two separate occasions. Nine of the 25 subjects
participated in a third trial when consumed coffee high in caffeine (H-CAF). Subjects
remained in the laboratory while urine samples were collected every 60 min for three
hours. Mean caffeine consumption for L-CAF and H-CAF trials was 254 mg and 552
mg, respectively. The subjects were habitual coffee drinkers (2-3 cups per day) who
abstained from foods and drinks containing caffeine or other methylxanthines 24 h
before each study. All sessions were performed at 0900 in a counterbalance, crossover
manner, at least 5 days apart.
rEsuLTs: Cumulative urine volume during the 3h period was significantly elevated
only in the higher caffeine trial (W: 292±165 ml, L-CAF: 316±194 ml, and H-CAF:
630±391 ml; P