To be a beneficial gymnastic exercise, every downward transition you make with your horse must involve engagement of his hind legs and lowering of his hindquarters. With some horses, that is not always easy to achieve! This analogy can really help riders improve their downward transitions.
"You can see suppleness by observing how the rider can sit on the horse and not on top of the horse." ~ Susanne Miesner
If you are hoping to improve the scores on your medium and extended gaits, improve your collected gaits.
From Facebook fan Dorothy Smith ~ "In riding, as In a dance, one leads, one follows, but both must love to dance for it to become art."
Give your older horses even more time to fully warm up before any challenging or strenuous work.