Interestingly, case reports from both Finland and Denmark suggest that aerobic exercise is able to markedly reduce FLS symptoms in MS patients, but so far no studies have evaluated this. However, from healthy subjects it is known that aerobic exercise is capable of positively influencing the immune system and evidence suggests that the prophylactic effect of exercise may, to some extent, be the 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).