What is the fastest way to level up your Pokemon in Pokemon heart gold?

Answer 1

So, you could use an Action Replay cheat for infinite Rare Candies, but if you don't want to cheat, there is a secret training place with level 31-40 Pokemon! On your way to the Safari Zone, you will enter a cave that has a guy in between two ladders. The left one takes you to the safari zone, but the right one is the one we want. Once you take the right ladder, exit the cave by moving south for 5 seconds. Use Surf on the water, and use Waterfall on the first Waterfall you see. Once at the top, Surf for another 5 seconds, and there will be a small ledge you can get on. It has a small patch of Tall Grass, and in that patch, you can find lvl 31-40 Pokemon, such as; Farfetch'D, Fearow, Miltank, and Ditto. The thing to do here is, battle Pokemon until you level up to the desired lvl. If you catch a Ditto, then put it in the Daycare Center with, say, Ho-Oh, or Lugia, or really any legendary, the Ditto and the Legendary will mate, and create an egg, which can hatch any rare legendary, from Suicune, to Arceus, to Darkrai!

Once this leveling up technique is to slow, obtain all 16 badges, and then battle at Mt. Silver. If you've obtained all 16 badges, and beaten the Pokemon League, travel to the top of Mt. Silver to battle Red (Ash). He has level 81-89 Pokemon. Once defeated, travel to Professor Oak's office, and he will give you either Charmander, Squirtle, or Bulbasaur (your choice). Also after defeating Red, travel to (I think his name is) Proffesor Birch's office, and he will let you choose from a Torchic, Mudkip, or Treecko. Also, after defeating red, travel to Mr. Pokemon's house, and he will tell you where to go to get the Blue Orb, and Kyogre. After beating Red, finish the Pokemon League again, and you can battle Red over again too at the top of Mt. Silver.

Answer 2

Have a Pokerus Pokemone it in your party, then level up or deposit a Pokemon to give it Pokerus. This does not always work.
Train a Pokemon that was traded to you also have it hold a lucky egg.

Answer 3

train you'r Pokemon up on high lvl's

train you'r Pokemon up on high lvl's

Answer 4

let them hold any berrie with the first leeter a B.

Answer 5

beat the elite four over and over again, you get so much xp, much more then fighting wild Pokemon

Answer 6

to level up with a weak Pokemon give it a exp. share. then go and complete the elite four easy

Answer 7

use rare candies or give a Pokemon an exp share

Answer 8

exp. share and the Elite Four

Also the lucky egg, which doubles your exp after a battle.