Another update was announced on Niantic’s website and on their Twitter!

Trainers,

As we continue to make improvements to Pokémon GO, we have made an enhancement to the Gym experience for Trainers of all levels. In an upcoming version of Pokémon GO, when training at a friendly Gym, Trainers will be able to bring six Pokémon to battle instead of one. In addition, the CP of the Pokémon you are training against may be temporarily adjusted lower during your training session to generally match your Pokémon’s battle capabilities.

No matter what your level, you can now have an impact on your team’s Gym. Walk with your Buddy Pokémon to that nearby landmark and show your Team Leader that you can battle with the best!

This gives players more of an incentive to train at their friendly Gyms. No longer would huge CP differences be a detriment to leveling up a Gym’s Prestige level; now six of your Pokémon would be able to have a significant impact, as well!

Hopefully this means that teams would be able to retain their Gyms for longer! Trainers, how would you use this to to help your nearby friendly Gyms?

Edited by bobandbill.