To bring your horse back to a state of fitness, you should start with slow work, mainly walking and trotting the first two weeks, then adding some canter work the third week. By the fourth week, you can start muscling up the quarters and improving the horse's wind by trotting up a long, gradual incline that has good footing--about three or four times up the incline three times a week. You can also do a little jumping at this point, doing gymnastics one day a week and practicing on single lines or single cross-country fences on another day in the week. The fifth week you could add some gallop work--about one minute of gallop two times a week--while doing the work on the incline on other days. From here on, devise a schedule based on the demands of upcoming competions, keeping in mind that your horse should be fit enough to have clear, rather than foamy, sweat when it is in hard work. The horse should also have an increase in muscle and a decrease in its "hay belly" as it becomes fit. Finally, the horse's wind should be sufficient so that the animal doesn't seem to struggle to get enough air during hard work. Once you observe these physical signs, you know your horse is ready to compete.