Triathlon
The sport of triathlon (swim, bike, run) has different distance races from a sprint distance (.5m swim, 25m bike, 5k run) to a full Ironman distance (2.4m swim, 112, bike and 26.2m run) and there are plenty of races available at all distances. I have participated in many events over the years including 6 Ironman Races, 4 in Lake Placid and 2 in Louisville. The sport has become so popular in many cases you need to sign up for a race one year in advance just to get a slot. Below are some triathlon links.