Ad libitum fluid consumption via self- or external administration.
BACKGROUND
During team athletic events, athletic trainers commonly provide fluids with water bottles. When a limited number of water bottles exist, various techniques are used to deliver fluids.


OBJECTIVE
To determine whether fluid delivered via water-bottle administration influenced fluid consumption and hydration status.


METHODS
Crossover study.


METHODS
Outdoor field (22.2°C ± 3.5°C).


METHODS
Nineteen participants (14 men, 5 women, age = 30 ± 10 years, height = 176 ± 8 cm, mass = 72.5 ± 10 kg) were recruited from the university and local running clubs.


METHODS
The independent variable was fluid delivery with 3 levels: self-administration with mouth-to-bottle direct contact (SA-DC), self-administration with no contact between mouth and bottle (SA-NC), and external administration with no contact between the mouth and the bottle (EA-NC). Participants warmed up for 10 minutes before completing 5 exercise stations, after which an ad libitum fluid break was given, for a total of 6 breaks.


METHODS
We measured the fluid variables of total volume consumed, total number of squirts, and average volume per squirt. Hydration status via urine osmolality and body-mass loss, and perceptual variables for thirst and fullness were recorded. We calculated repeated-measures analyses of variance to assess hydration status, fluid variables, and perceptual measures to analyze conditions across time.


RESULTS
The total volume consumed for EA-NC was lower than for SA-DC (P = .001) and SA-NC (P = .001). The total number of squirts for SA-DC was lower than for SA-NC (P = .009). The average volume per squirt for EA-NC was lower than for SA-DC (P = .020) and SA-NC (P = .009). Participants arrived (601.0 ± 21.3 mOsm/L) and remained (622.3 ± 38.3 mOsm/L) hydrated, with no difference between conditions (P = .544); however, the EA-NC condition lost more body mass than did the SA-DC condition (P = .001). There was no main effect for condition on thirst (P = .147) or fullness (P = .475).


CONCLUSIONS
External administration of fluid decreased total volume consumed via a decreased average volume per squirt. The SA-DC method requires fewer squirts within a specific time frame. Fluid breaks every 15 minutes resulted in maintenance of euhydration; however, loss of body mass was influenced by fluid administration. Athletic trainers should avoid external administration to promote positive hydration behaviors. When fluid is self-administered, individual bottles may be the best clinical practice because more volume can be consumed per squirt.
Department of Physical Education and Athletic Training, University of South Carolina, Columbia;
Susan W
SW
Yeargin
Megan E
ME
Finn
Lindsey E
LE
Eberman
Matthew J
MJ
Gage
Brendon P
BP
McDermott
Andrew
A
Niemann
D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D003681:Dehydration / Q000209:etiology / Q000517:prevention & control*; D004326:Drinking / Q000502:physiology; D060766:Drinking Water / Q000008:administration & dosage; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D012646:Self Administration; D013894:Thirst / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000502:physiology
D060766:Drinking Water
disease transmission; fluid breaks; hydration; water bottles