Pokémon Sunday clarified a further Pokéthlon details.
Firstly, your Pokémon are rated based upon several bits of criterea including Speed, Stamina, Power & Jump.
Secondly, two of the Pokéthlon events are known.
-First is Dash Hurdles which runs like a standard sprint. Your three Pokémon are all controlled by you and you have to tap the Pokémon to make them jump in time, allowing for them to continue. The quicker you do it in, the better your Pokémon score.
-Secondly is the Bound Field. This one features your Pokémon on a trampoline. There are numerous gold targets on the top screen and you have to make the Pokémon jump up to hit the targets.