Instructions
Go to the National Park in Johto and bring along at least three Pokemon. Give the Pokemon shaking Apricorns to improve their stats. If your Pokemon has higher stats, it will perform better in mini-games. Head west of the National Park and you will eventually find the Pokeathlon Dome.
Choose one of the following categories: Speed, Power, Skill, Stamina and Jump. Select three Pokemon to compete in the Pokeathlon events. These three Pokemon should have stats that reflect the category you chose. For example, if you chose "Speed," your three Pokemon should have high speed stats.
Beat the first and second records for every game in the category you chose. For example, if you're playing Hurdle Dash, you would earn 100 points to beat the first record and 80 points to overcome the second record.
Use the points that you earned to buy Apricorns at the Pokeathlon Dome Store. Each Apricorn costs 200 points. Feed these Apricorns to raise the stat of your Pokemon. For example, the Pink Apricorn raises the Speed stat.
Enter three Pokemon in the other four categories. Beat the first and second record for all 10 games. Once you accomplish this, you will gain access to the fourth room of the Pokeathlon Dome, where you will find golden trophies for each event.