The last thing any runner wants to deal with is chafing, which comes from skin rubbing against either skin or clothing over extended activity. Friction can easily irritate such areas as the thighs, underarms, and groin. 

Long-distance runners like Jimmy are most certainly prone to this, especially when hyper sweating exaggerates the problem. Prevent chafing in the first place by only wearing moisture-wicking, breathable materials that keep skin dry. 

Anti-chafing balms or petroleum jelly also can be applied to hot spots before running. Compression shorts should help also by eliminating some of the skin-to-skin contact. Afterwards, gently clean the affected areas and apply soothing lotions. These strategies will help runners focus on performance, not discomfort.