I feel your analogy needs a fourth sport to complete the 4 elements. But what sport would be represented by fire? Perhaps competitive shooting (gunpowder=fire)
This year I'm doing a "Swedish Classic", which is 4 long distance races throughout the year. Three of them are the classics in triathlon, but the fourth is cross country skiing (or "nordic skiing"). So the opposite of fire, hmm, but could maybe say that fire is what makes it possible to traverse 90km of mountains in the winter.
Maybe the participant is the fire, interacting with the three other elements?
The fourth sport in a regular triathlon is transition. You burn away any lead you had (as you can't get your shoes on etc) and emerge from the flames reborn as a new type of athlete.
How about swimming in an onsen swimming pool (make one if not exist)?
I used to do a mini triathlon, it feels like hell already!