I can't help speeding up to catch people sometimes, but I don't alter course if I get tired. Well I wouldn't, anyway. That's lame-o. So far everyone I've dropped stays dropped, because if I can't pass someone without getting my HR up to 100% I don't. Nothing says puss-y like a guy who blows past someone to show off and then hides.
And anyway, dropping someone is not "racing" someone. Last time I checked, "racing" involves buying a license and getting a number.