Purpose: Gastrointestinal (GI) symptoms are common during prolonged intense exercise. To examine whether GI symptoms are also common during prolonged exercise of lower intensity, we obtained data on incidence, duration, and severity of GI symptoms during four consecutive days walking with a total distance of 203 km for men and 164 km for women.
Methods: The research population consisted of 79 men and 76 women, aged 30-49 yr, who responded to a questionnaire and a diary concerning anthropometric data, activity pattern, dietary intake, and GI symptoms.
Results: The results show that 24% of the subjects experienced one or more symptoms. Nausea, headache, and flatulence were the most frequent symptoms. Nine subjects dropped out during the race, two of whom indicated that they stopped as a result of one or more GI symptoms. Logistic regression analysis revealed that the occurrence of GI symptoms was a significant exercise-limiting factor. Univariate analysis showed that incidence and duration of GI symptoms were significantly related to the subjects' experience (number of prior participations to the event), body weight loss during walking, and several components of the diet before and during the event. A significant relationship between GI symptoms and age, gender, training status, and walking speed could not be found.
Conclusions: We conclude that GI symptoms during long-distance walking can impair exercise performance, although these symptoms occur less frequently and are less severe in comparison with prolonged intense exercise.