Once your horse is 2 years old it can participate in training. The training meters are on the right side of the page (If your horse is in the center). There are 6 categories- Stamina, Speed, Dressage, Gallop, Trot, and Jumping. Click on the green plus button next to one to train your horse in that category. Some breeds horses are better at the categories than others (ex. Thoroughbreds are better in Speed and Gallop, but they're not as good in Jumping). Choose a time to train your horse, and it will show the gain of training and the energy loss. I usually try to make the energy loss between 70% and 80%. Then just hit 'Train' and it will train your horse for you! If you want after that, you can feed it some granules to give it energy (Tip: Save a turnip, apple, and salt block for after training, then you can give those to it and give it the granules, and it might have some energy left over after that to squeeze in some more training. Don't go over the limit, though, or the next time you age your horse, it might need a day to recover. Try to have AT LEAST 15% of energy left). If your horse has a Chronos's Timer (Available at the Black Market for two passes) your horse will train twice as fast. Hope that helped!