An erection that occurs during strenuous physical activity, specifically running. Although widely regarded as a mythical phenomenon, the release of endorphins during both exercise AND orgasm adds credibility to this "bigfoot" of penile erections. Detractors point to the common, contradictory phenomenon that is runner's penis.
Still reeling in his post-marathon "high", Eric did not notice his runner's boner peaking out of the top of his shorts.
by yipplezz October 23, 2010