Effects of a pre-moistened multilayered breathable fabric in promoting heat loss during recovery after exercise under hot conditions.

REASONS FOR PERFORMING STUDY

Horses generate considerable internal heat burdens when exercising. Although common practice for a trainer or groom to place a wet blanket or towel on the dorsum of a hot horse post exercise, there are no data supporting the efficacy of this cooling method.

OBJECTIVE

To test the hypothesis that a pre-moistened blanket designed with a multilayered breathable fabric would enhance heat loss in horses post exercise.

METHODS

Eight treadmill-trained horses performed a standardised exercise test (SET) weekly for 3 weeks, with 3 different recovery treatments administered randomly. Pulmonary artery temperature (PAT) was measured via Swan-Ganz catheter. The SET consisted of 10 min at 3.7 m/sec, 3 min at 11.0 m/sec, 25 min at 3.7 m/sec and 20 min of recovery walking at 2.0 m/sec (58 min exercise and recovery under laboratory conditions of 35.0-40.6 degrees C and 27-49% RH). From 3-7 min during recovery, the treadmill was stopped and horses randomly received either: (a) no bath (negative control); (b) a bath consisting of 32 l of 1-4 degrees C water split into 3-4 cycles of bilateral water application (positive control) followed by water removal ('scraping'); or (c) application of a multilayered fabric blanket soaked in 16-19 degrees C water, wrung out, and placed over the dorsum and sides of the horse. PAT was compared using RM ANOVA with the Student Neuman-Keul's test used post hoc to discriminate between treatments at specific points in time.

RESULTS

Mean PAT rose with each phase of exercise (P<0.001) and peaked at a mean of 40.2 +/- 0.2 degrees C. During recovery, the cold bath decreased HR and PAT for 9 min after walking resumed (P<0.001-P<0.05). The blanket did not decrease HR or PAT compared to negative control (P>0.05), and both were hotter than the cold bath treatment through 16 min of recovery (P<0.05).

CONCLUSIONS

A specially-designed cooling blanket failed to reduce PAT when compared to negative control. Cold water bathing decreased HR and PAT but was not effective throughout all of recovery.

POTENTIAL RELEVANCE

A specially-designed, pre-moistened multilayered breathable fabric failed to promote evaporative cooling compared to negative control. Cold water baths may need to be repeated throughout recovery to optimise their effect.