We must start with the end in mind. What needs to be improved? Is it something you can feel or see (eg on the lunge)? Is there any difference between the trot loose, on the lunge, ridden? Does he have a naturally good trot? Is the need for improvement more visible in certain trot variants ie working, medium, extended, collected. How does he compare to other horses you ride or see working? How would you describe the symptoms you see or feel? What do you think are the possible causes? Until we fix the root cause we'll not fix the problem, we'll just mask it. A good way of tracing root causes is to ask why 5 times or even more.............and you need to be really honest.
The consensus among trainers is that trot is an easier pace to improve than canter; but only within the individual horse’s limitations. To do this we need to encourage the horse to push more from behind. The hind leg needs to carry more weight so that the forehand can lighten, and the trot becomes "more uphill".
This is easier said than done, particularly with a young horse (and even more so with a big young horse) as they easily lose their balance. Often the answer becomes more leg, but this just increases the speed and the horse becomes more and more unbalanced and leans on the hand. It is a bit like a child running down hill faster and faster - more and more unbalanced - and a lot of tears at the bottom. To engage the hind leg we often need to slow the trot and give with the hand. Whenever he dives onto the hand and quickens, slow him again and give with the hand (a long-as-needs-be half halt). You will really need to support him with your body and particularly the strong spring in your lower back.
Generally, I don't "work" the trot until I've cantered. First of all I warm up in walk and trot on a relatively long rein - concentrating on forwards and bending (corners, circles). I encourage him to listen to me through lots of transitions. The canter loosens me and him and gives "spring". Canter, trot, canter transitions on a 20m circle with a very light hand and concentrating on being as quiet as possible. I agree with Kyra Kyrklund (18) that the best trot comes after a good canter-trot transition, and the best canter after a good trot-canter transition.
Smaller (10m) circles help to engage the hind leg; really think about the inside hind on the circle and feel you can suck it up and under - then go large and try to keep the same feeling of the trot on the smaller circle but without using the rein - just your body. On the circle, check you aren't blocking or holding on the inside rein by smoothly giving it - the outline and the circle shouldn't change..........
In transitions (walk-trot-walk; halt-trot-halt), the rider must be soft and connected, especially in her seat and hands. The horse seeks the contact. The rider only carries the weight of the rein plus an ability to feel the horse. Downwards transitions develop collection, the carrying capability of the hindquarters, and balance. Upwards transitions develop engagement, the pushing capability of the hindquarters, and strength.
Shoulder-in down one half of the long side then straighten and release through your seat to gradually extend the contained power of the shoulder in. Or use the power to create true straightness and purpose across the diagonal. Remember, you need to carry yourself evenly and look at something at eye height in the direction you are going. Ride a small circle before the shoulder-in to really help. Balanced extension can only come out of collection. The feeling should be of releasing the contained energy that is already there, rather than creating it in that moment or "making him do it". You should feel that it is there for you all the time as you have created it with all the previous work.
The hand must give all the time, it should never block, as then the hind leg cannot come under and the back can't swing. Make good use of the rising trot....but remember you can still block with your body and hands in rising trot - stay relaxed, in balance and giving.
Keep varying the pace in the trot - forward and back. For example, contain it on the long side - release and lengthen a little through the corners and short sides.
You should be able to vary the outline too. In a long and low outline our horse is never behind the vertical. His nose should be level with his shoulders and no lower. This gives sufficient stretch. Remember to control the transition between outlines and don't let him dive down. Use the seat before shortening the rein - make it smooth - practice and practice. Do it by feeling, not by thinking about it. You need to be in a really calm, quiet, confident place in your head for this to work. This is not about control, it’s about communication.
I have been experimenting with the use of poles on the ground – both on the lunge and ridden. They add interest and variety. They help to maintain attention. They make the horse aware of his movement pattern. He must think about how he can use his legs in different ways. Poles can be used to help de-contract the horse. The rider should stay in balance, relax and allow. Poles can also be used to train the horse to trot in different ways. Over time the rider can associate the feeling over the poles with a difference in her seat. The idea is for the feeling over the poles to be recreated without poles, at will.
Tracking up
Tracking up can be an indicator of engagement. However, conformation is a big factor here. Also, it tells us nothing about collection or extension. Paul Belasik (7) concludes that to truly determine stride length we have to measure actual length of stride.