Simba in the desert as he is on his way back to the pridelands to fight or battle Scar..but running in the sand and in the heat must have been hard..so i assume he would stop running to catch his breath and gain some power..but hard in such weather! And consider that lions cant run long before they get warn out fast!
The desert just isn't very big. That whole montage where he's galloping back to the pridelands? It's not a montage, that's literally how long it took him.
If you think about it, actual lion prides are ruled by more than one 'king', which totally debunks the whole story....
But still a good concept!