My coming four-year-old TWH does the stepping pace when we gait fairly slowly. However, when asking for any speed, he breaks into a hard pace. I've had him for about a year and walk him about 98% of the time. I've started him slowly and have gradually asked for more reach and speed at the walk but as soon as he breaks into gait, its pace,pace,pace. His gait gets very rough when going downhill. That is his gait of choice in the pasture as well. He likes to travel with his head up high so I'm sure his back is far from rounded. I've been trying to get him to lower his head and round his back but so far, no luck. Any suggestions?

Plan to take this slowly. Your 4-year old is still very young to be performing proper gait at speed. I wouldn't expect it. What you're doing now is totally appropriate--but more on that later in this answer.

The first most important thing to do is make sure the animal is comfortable. The fact is, most of the horses I deal with are in pain, and their owners don't know it. You can't hope to obtain a good, fluid gait if the animal is stiff and sore. They need to be very well fit for saddle and bit before gait training can progress.

Most traditional types of saddles are not appropriate for our horses. Walking horses used to be ridden only in saddle seat saddles. Today most riders prefer a trail saddle, usually western. A good running walk (or fox trotting) horse really should have a saddle with some kind of flexible tree. I want every single gaited horse owner to own a saddle that really works for them and their horses. - See our Imus 4-Beat™ Saddle Here

Please, do NOT purchase a saddle just because it's touted as a 'gaited horse saddle.' I've found that many of these simply do NOT work very well-the horses need more flexibility than these generally allow.

If you cannot purchase a different saddle, then at the very least invest in an open cell style pad to alleviate pressure points. Most gaited stock need so much more flexibility through the loins, back and neck that it is almost certain that a rigid tree system will cause pain, and limit an animal's ability to obtain and sustain a good quality gait. Supracor puts this pad out, and I've been very impressed by it. It's not cheap--but costs much less than an unsound horse, or an entirely new saddle. 

All this may sound like just so much product 'hawking,' but I assure you it's not. I never intended to do more than offer instructional information, as I'm a teacher at heart. But it's been painfully evident that our horses desperately NEED products that allow them greater freedom of motion and flexibility throughout their loins and backs, and bits that are effective, but not painful. So this business has had to evolve to offer products to address these issues, so that I could get one with the business of helping people to train for gait.

The downhill pace is very difficult to take, isn't it? You deal with this by using a good, limited action three piece bit (NOT a 'walking horse bit'), and then use each rein to pick up the horse's shoulder just as that side's leg begins it's downward arc. It takes practice, but this will change the timing of the gait, and encourage the horse to shift his weight more backward. . .which will solve the problem. Be patient with yourself and with him, and this technique will prove very useful.

May all your trails be happy, and smooth!