My horse is about 28 years old and is in overall good health and shape. I just want to practice with him so id only do it 2 or 3 times a week. Plus he has done barrel racing for quite a few years.Is he to old???
As long as he can comfortably run the pattern, then no, he isn't too old. I personally wouldn't really ask him to go full out but he should be fine for practice and probably even an event or 2 if you were interested.
If your horse enjoys it, and he is relatively good shape, I see no problem with it.
There was a thread similar to this one started a day or 2 ago. I will give you the same advice I gave to the OP of that thread:
A training tip for you:
Slow work can be just as (if not more) effective as fast paced work. Running perfect patterns at the walk/trot will translate to better runs when you put the speed into the mix. It is also better on the horse.
If he is still in good condition let him run his heart out :) I know that one of my borders has a 30 year old that is in great shape for her age and is still playing around with barrels and she loves it!