[Effects of jogging on mental well-being and seasonal mood variations: a randomized study with healthy women and men].

The long-term effect of jogging on mental well-being and seasonal mood variation was examined in a randomized, controlled intervention study with healthy, middle-aged, sedentary, non-smoking, white collar subjects. 17 women and 39 men were allocated to jog 2 h/week for 4 months, whereas 16 women and 22 men served as controls. After 4 months, there was a partial cross-over with the controls now taking up jogging. After 8 study months, all 38 subjects of the second jogging intervention as well as 10 women and 30 men of the first 4-month jogging period were re-examined for the second time. All participants in the second re-examination were mailed a survey questionnaire one year after beginning of the study (response rate 83%). Despite varying adherence for the exercise regimen, the 4-month "net effects" (i.e. effect in exercise group minus effect in control group) showed a significant improvement in physical fitness (endurance capacity, resting heart rate) in men, but not in women. Among the mood scales assessed, "anger" showed a marginally significant effect in men (relative decrease; p = 0.05) and "calmness" a significant effect in women (relative increase; p = 0.02); after exclusion of 4 non-compliers from analysis in women, also "vigor" (relative increase; p = 0.03) and "depressiveness" (relative decrease; p = 0.02) were significantly improved after jogging. In women, the number of kilometers run was significantly correlated with an improvement in mental well-being (Pearson's r = 0.32 with change in 4 "positive" mood scales and r = 0.57 with change in 4 "negative" mood scales). Changes in endurance capacity were not significantly related to changes in mental well-being. However, in both women and men these mental effects of jogging were superposed by clear seasonal variations in mood, i.e. by a deterioration of mental well-being during the winter months and by a slow "remission" during summer. Taking jogging-induced and seasonal effects on mood together, the magnitude of the 1-year variability in mental well-being was somewhat attenuated in those study groups jogging, with this "buffering" effect reaching statistical significance in women (p = 0.050). We conclude from this training study with normal subjects that regular jogging of approximately 10 to 15 km/week may help to diminish the deterioration of mood observed during winter months (e.g. increase in depressiveness), especially in women. Hereby, a training-induced increase in endurance capacity is apparently not a prerequisite for this long-term mental effect of jogging.