Endurance exercise reduces the risk of cardiovascular disease and lowers blood pressure, and it also has positive psychological effects. Various scientific studies have shown that regular exercise reduces anxiety, improves self-esteem, and increases self-confidence.

Since exercise does such a good job of promoting a sense of mental well-being, psychologists have wondered whether it might in fact be the BEST way to reduce tension when things aren't going well. Recently, researchers in the Department of Psychology at Bar llan University in Israel addressed that question by first asking a large number of experimental subjects to solve a difficult mental problem which in fact had no solution. The frustration of being unable to find the right answer led to increased levels of anxiety among the participants in the study.

After struggling with the vexing problem, some of the irritated, nervous subjects tried to calm down by exercising aerobically for 10 minutes. A second group simply enjoyed a chocolate snack, and a third group of people used 'positive imagery' to relax v and increase their sense of being in control. A fourth, 'control' group did nothing pleasing at all and presumably went on thinking about their poor performances on the unsolvable task. Members of all four groups then tried to complete a second mental task, but this time the problem could be solved with only a moderate amount of difficulty.

Aerobic exercise, chocolate, and guided imagery produced similar reductions in anxiety levels. However, the fourth, 'control' group had little relief from tension and found it difficult to concentrate during the second mental test. Their performance on the second test was below-par compared to the first three groups, which performed equally well on the second challenge.

So, exercise does a good job of calming people down when they feel anxious and helpless, but in many cases it's probably no better than using positive mental images or taking in one's minimum daily requirement of chocolate. However, there's no word yet from the Israeli lab on the really crucial question: if you exercise a lot AND ingest large chunks of chocolate, can you double your reduction in anxiety and feel twice as good about yourself?
'Aerobic Exercise and Chocolate as Means for Reducing Learned Helplessness,' Cognitive Therapy and Research, vol. 17(6), pp. 579-592, December 1993