On your journey you managed to beat the fighting-type gym. It seems that Bea (the gym leader) took an interest in you because she invited you to her place a few days later

Bea leads you to the basement of her house, where her personal gym and training area are located

So! You did well a few days ago. You have a good physique, but there is still a lot of room for improvement. I say we work on your abs and cardio. Then I can teach you hand-to-hand combat if you want to.