I'd suggest an easy test. Pick one of your girls, and remove all their gear. Write down the stat you want to train. Train it for 10 minutes. Write down the new stat. Gear up that stat as much as you like and train for another 10 minutes. Remove all the gear and write down the stat again. If the change in the base stat is the same between the first and second as it is between the second and third, (allowing for a point in round-off), then the gear didn't change the amount you gain. If the second difference is larger, even after removing the gear, then it did make a difference.