Least appeal-swimming. When you are competing others only see your backside as you are primarily face down partially submerged. Your hair and eyes are hidden by a swim cap and goggles. Everyone looks alien. You train long hours going back and forth in a pool in your own little world. No one can see your face so no one knows who you are. It's hard to be an individual and express yourself. Few believe your activity is cool and you will not make much money.
Mid appeal-bicycling. Everyone wears a helmet with sunglasses and so no one sees your face and knows what you look like. Everyone looks alien. You wear the same kit as your team so its hard to stand out as an individual. You can't express yourself with hair, nails, jewelry because it would not be aero and would slow you down. When you compete as a cyclist you go by so fast that it's hard to identify you. You can make lots of money and ride fast, but it's dangerous and you will crash and become injured. It can be frustrating when people are more interested in the tech of the bike you ride than they are in you.
Most appealing-running. Your face, body, hair, nails, makeup are totally visible to all when racing and training. You get to show off your athletic body wearing as little as possible. People can see and recognize you because you are not moving that fast and are either running around on a track in a stadium or out on public roads. You can express yourself as an individual and some of the fastest runners in the world compete wearing elaborate jewelry, wigs, long nails and make-up. But your activity is not that cool and you will only make a little money.