I know that this is an older post but I wanted to offer a bit of a take on this. I know that we probably don't equate a fan as training and depending on what you are using that fan for, it might not be. But if you use it up specifically for strengthening the stem or branches, what are you doing? You are training it to do what you want.
Most of us use fans to keep the air moving and to prevent pests from getting easy access to the top of the soil. Its probably not the best form of training for strengthening up branches and stems. I have found that shaking the plants (gently when they are seedlings, and more aggressively as they grow stronger) or their branches, you can see crazy increases in the strength and rigidity of the plants.
Shed, you remember how lanky my ATF was about a week or two ago? I have been shaking that solo cup back and forth a few times a day to simulate higher winds that trees and plants experience in nature. In less than a week, it doesn't even look like the same plant. It has virtually no bend in the stalk as I shake it now. I have been doing the same things with my Tangie Ghost Train clones and the branches are strengthening up faster than any other methods I have tried. Original credit on this technique goes to Dabber, but I took what I saw him doing and started doing it on my seedlings and I can assure it is training!