Lead author Stacy T. Sims of Stanford University in California said the cooling device called the AvaCore Rapid Thermal Exchange chilled the palms of the hand and circulating blood, pulling heat off the body.
The 12-week study, involved 24 obese women, ages 30-45. Half worked out with their hands in a cylinder containing water at 60.8 degrees Fahrenheit. The other half used the same device with water at 98.6 degrees Fahrenheit -- body temperature. Participants didn't know the difference in their devices and did the same fitness activities.
"The control group dropped out quite early," Sims said in a statement. "The women who had the cooling device continued to participate and didn't have an issue with attrition because they finally didn't feel uncomfortable exercising."
In addition, the cooling group:
-- Shaved an average 5 minutes off the time to walk 1.5 miles.
-- Dropped almost 3 inches off their waists.
-- Had lower resting blood pressure and greater exercise heart rate.
The device used in the study is costly and is typically found in professional sports training facilities, but Sims suggested holding a water bottle of cold water might also cool palms.
The findings were presented at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism scientific sessions.