Cantered yesterday.  Only a few strides then back to trot.  Asked once and he sped up but didn't change gait.  The second time he responded.  Need to do it enough so that it becomes, in the words of Tom Roberts, Old Hat.  Cantering 20m circles, doing lots of transitions will also help him to build muscle, become handier, fitter and stronger.  I love doing the transitions at the walk, trot, halt, back up.  Break them up with long trots or walks around the arena or having a walk outside the arena.  Our farrier trimmed his feet on Thursday.  He checked the fit of the Trail Easy Boots.  How could I be two sizes off?  Measured and remeasured before ordering but now have gone from size 5 and 6 to size 4 and 5 and really need to go down to size 3 (hind feet) and 4 (front).  That's two sizes out.   Anyway, need to get out and ride if I'm going to do it as it's supposed to be 35 today and probably 38 tomorrow!