You are probably sprinting to the bus stop, not running. Running would be below your aerobic threshold, for however well you're trained, and thus should not leave you exhausted or wiped out. The general rule of thumb is that if you can't have a conversation, you're exceeding your aerobic threshold and so are exceeding your pace.
Training increases what that pace is, but ultimately no (land?) mammal can exceed their aerobic threshold for long, since there are limits to stored oxygen. Cetaceans and pinnipeds might be an interesting exception.
Training increases what that pace is, but ultimately no (land?) mammal can exceed their aerobic threshold for long, since there are limits to stored oxygen. Cetaceans and pinnipeds might be an interesting exception.