Do any of you British slashdotters in University have access to the full text of the second article? The brief description in the "methods" section doesn't say if the researchers were monitoring or controlling the diet of the subjects. It seems absurd that they would not, but it's possible that the lack of weight loss was partially caused by an increase in caloric intake. After all, the stated intent of the research was to study how the health benefits from exercise are affected by changes in body weight, not whether exercise is necessary or sufficient to achieve weight loss. The major result from the British study points out that exercise can make one a healthier and happier individual even if one doesn't lose much weight. The Colorado study refutes the popular notion that exercise causes an "afterburn" of fat. Both exercise and a diet change are necessary for weight loss, but neither one is sufficient by itself. Why is this surprising to anyone?