The American College of Sports Medicine reviewed past research on how exercise can reduce the risk of developing some cancers by as much as 69%. The data also showed how exercise can improve treatment outcomes which in turn can prolong life. One line of thought is that exercise can lower inflammation in the body and therefore cultivate an environment that is less friendly to malignancies. In a new study performed at Karolinska Institute in Stockholm, scientists inoculated two groups of rodents with cancer cells. One group was allowed to be extremely active while the other remained sedentary. They noted that in the group that was active there was very little evidence of tumor growth. The T cell (immune fighter) that they attributed this to is the CD8+ T cell. What they also discovered was when they suppressed this particular T cell, regardless of how much activity, tumor cell growth was no longer suppressed. They then isolated and injected the CD8+ t cell from active rodents into sedentary rodents and found that their tumor growth was suppressed. After removing blood from the active rodents, they determined that their blood contained a large amount of lactate produced from exercise. Bathing T cells in lactate produced stronger cancer fighting T cells. There appears to be a profound effect that exercise has on the ability of the T cells to suppress tumor growth and how these cells remain persistent in fighting cancer over a period of time.