Energy, tiredness, and tension effects of a sugar snack versus moderate exercise

After either eating a candy bar or walking briskly for 10 min on 12 selected days, 18 volunteers made systematic self-ratings of their energy, tiredness, and tension feelings for a fixed 2-hr period each day in the context of their normal daily activities. The snacking or walking activity was randomly selected on each test day after completion of a pretest. Results indicated that walking was associated with higher self-rated energy and lower tension significantly more than was snacking. In the walk condition reliable increases in energy and decreases in tension were observed for 2 hr. The sugar snack condition was associated with significantly higher tension after 1 hr, and a pattern of initially increased energy and reduced tiredness, followed 1 hr later by increased tiredness and reduced energy. The results partially support a general conceptual hypothesis that sugar snacking is often motivated by a low-awareness attempt to raise energy. Additionally, the results clarify an apparent conflict between neurochemical research, which indicates that sugar ingestion increases the tendency to sleep, and popular nutrition theory, which indicates that it increases tension.