INTERACTION OF EXERCISE AND CONCENTRATION ON OVERALL ACCEPTANCE OF A SPORTS BEVERAGE IN OLDER PEOPLE 1608

Abstract

To determine the interaction of exercise and beverage concentration on overall acceptance (OA) and perception of flavor characteristics in older people, we exposed older men (n=7) and women (n=17) (72.2±5.8 yrs.) to five concentrations of a powdered sports beverage (SB). Beverages were 10%, 50%, 100%, 150%, and 200% of the control (100%) concentration and randomly sampled in both sedentary (SE) and post-exercise (PE) conditions. SE consisted of sampling all five beverages in a single session. Subjects then performed 40 min of aerobic exercise on mini-trampolines (65-70% of predicted maximal HR reserve) on 3 days per week for 4 weeks. Immediately after each of the last five exercise sessions, one of the five SB's was provided ad libitum and 19 sensory and perceptual attributes were rated by self-report on category and visual analogue scales. There were no differences in OA scores among the five SB's in the SE condition. While exercise increased ratings of tiredness, thirst, and mouth dryness (p<0.05), there were no differences in voluntary intake among SB's. In this older group, thirst and fluid intake were not related. The largest positive shift for OA was for the 50% SB at PE(5.9±1.5) compared to SE (4.8±1.9). OA appeared to peak at the 150% SB in PE, but had a broader range of acceptability. Hedonic measures of sweetness and flavor favored the 150% SB after exercise. As a measure of discriminability, ANOVA F-ratios for sweetness and flavor strength were greater in the PE than in the SE condition, but for aftertaste, were lower in PE than in SE. Our data indicate that in older people, exercise may modify the ability to discriminate individual attributes of flavor and broaden the range of acceptable SB concentrations. Although thirsty, our older subjects had a limited fluid intake even though most SB's were reported to be acceptable as fluid rehydration alternatives.