By training, do you mean level-up or EVs?
Level-Up: I assume you are heading toward the sixth gym leader. If you just continue on your way using Anorith with frequency, it should be a good enough level. If you feel it needs more training, just fight some Tropius and such in the Grass, although it will be a slow, tedious process.
EVs: You'll want 252 Attack, 188 HP, and 68 Defense. Route 106 is a good place to EV train in HP, Route 119 wit the Super Rod for Attack, and Route 113 for Defense.