Pokemon Sapphire Gym 5!!?

Question

I need a great place to level up before beating gymleader dad!

I have already have

marshtomp 28

kirlia 26

torkoal 27

trapinch 23

roselia 28

swellow 25

Im looking to prob be around 35-45 before i challenge him so please help!!

Answer 1

try up by the place where you meet the person who invented the pc storage for pokemon and go in the caves or out in the grass

Answer 2

kk well id say get everyone up to level 38 if you really wqanna train that bade i mean i never have to just train cuz im keeping all my pokemon up to standards

i think you should train them on the cycling road  in the volcano thingy the powdery grass and maybe in the water rout betwenn slaport and deford