When I think of athletes, I think of the cognitive function Se, which is the strongest in MBTI SP types. Yet, in order to be an olympic athlete, you need an extraordinary amount of self-discipline and be able to stick to a rigorous practice routine. This is something, I associate more with J types. I would think sensing would have an advantage over intuition since it is sports, which are highly physical and in the moment. I'm guessing SPs with a strong J side might be the best contenders? I'm not sure SJ types would be as inclined as SPs to take the physical risks that are needed to perform at an elite level in a given sport. I suppose it depends on the sport- some have a greater risk of injury than others.
What about T/F? I'm guessing its not the most important factor but I would think T would edge out just because I associate the Olympics with competition and typically T types are seen as more competitive and F types as more cooperative.
E vs I is interesting. I've seen alot of both types in the Olympics. I think I's would gravitate more towards individual events like the marathon while Es would gravitate more towards team sports. I think an introvert would have an easier time with the self-focus aspects and sacrificing a significant part of one's social life to devote to practicing. On the other hand, I would say introverts would be far more publicity shy and if you're going to be an Olympic athlete, you have to be prepared for millions of people around the world watching you and tracking your performance.
Resilience is also a very important aspect, which goes beyond the MBTI. In a way it would be inversely related to neuroticism in the big five system. The ability to keep cool under intense pressure. The ability to not get discouraged by setbacks. If you're an aspiring Olympic athlete, there will probably be several on the way.
On the enneagram side, I think type 3 would be by far the most common. This is the type that seeks success and sets goals.