Join Date: May 2007
Location: Fairbanks, Alaska
If it were me, I would not practice any of those events that are held at the rodeo on a regular basis. I would focus my training on softening to the bit, suppling, and basic english/western riding maneuvers. Practicing your basic maneuvers, softening, and suppling will end up helping you have control and a calmer horse when you do participate in the rodeo.
Participating in such a high adreniline activity may have some negative effect on your training initially, but if you only do it once a year it should not have huge impact.
Over time, if you are consistent and calm with your training, you may be able to participate a little more often in gymkana type events without lasing negative effects.
All I know is that I have seen too many horses that do only gymkana who: run through the bit, run around with their heads up in the air, don't stop, run out of control, and have no basic balance or understanding of how to move properly. That is why I would suggest to focus training away from that and just do that as a fun extra on the side.