Running News Daily

"While general exercise boosts the immune system, endurance events cause a brief dip in our immunity levels, post-event," explained physiologist Prof Neil Walsh. "Our hunch is that the way in which our body's immune defence works during stress, like a marathon, is to some extent predictable. Runners in one of Britain's toughest races (Snowdonia Marathon in Welsh) could help scientists answer why some will fall ill after the race - and others will not.