too much exercise is bad for the immune, moderate is great . very heavy article

just an fyi, i am staying on the exercise theme

http://www.ncbi.nlm.nih.gov/pubmed/21446352

from the article
Because immune function is critical to host survival, the system has evolved a large safety net and redundancy such that it is difficult to determine how much immune function must be lost or gained to reveal changes in host disease susceptibility. There are numerous examples where exercise alters measures of immunity by 15-25%. Whether changes of this magnitude are sufficient to alter host defence, disease susceptibility or severity remains debatable. Chronic inflammation is involved in the pathogenesis of insulin resistance, atherosclerosis, neurodegeneration, and tumour growth. Evidence suggests that the prophylactic effect of exercise may, to some extent, be ascribed to the anti-inflammatory effect of regular exercise mediated via a reduction in visceral fat mass and/or by induction of an anti-inflammatory environment with each bout of exercise (e.g. via increases in circulating anti-inflammatory cytokines including interleukin (IL)-1 receptor antagonist and IL-10). To understand the mechanism(s) of the protective, anti-inflammatory effect of exercise fully, we need to focus on the nature of exercise that is most efficient at allieviating the effects of chronic inflammation in disease. The beneficial effects of endurance exercise are well known; however, the antiinflammatory role of strength training exercises are poorly defined. In addition, the independent contribution of an exercise-induced reduction in visceral fat versus other exercise-induced anti-inflammatory mechanisms needs to be understood better. There is consensus that exercise training protects against some types of cancers. Training also enhances aspects of anti-tumour immunity and reduces inflammatory mediators. However, the evidence linking immunological and inflammatory mechanisms, physical activity, and cancer risk reduction remains tentative. (ABSTRACT TRUNCATED)

hugs,
pete