I don't agree with this idea.
Reasons:
1. Gyms aren't that hard to beat and its at a beginners level so that its easily completable by the new players. So awarding something to completing gyms won't be a good idea as already winning gyms give good cash.
2. Will make players lazy and players will just use cycles to go over pokemons without fainting. Worrying about fainting is what makes it more challenging and fun to travel. Thus, will make the game much more easier and will spoil the challenge in travelling to new towns.
3. You have sprint to walk faster and thats more than enough to match the speed for cycles and you can walk if you don't want sprint mode
4. Finally Rise has an uniqueness compared to other games and we don't want it become common with the usual ideas in other mmorpg.
Moreover, if you really love that feature then why not play those games and rise to have a variety in your gameplay