I'm probably getting on here too late to help you out any, but I hope you were able to get things under control. The only breathing exercises I've been taught are to inhale slowly and deeply (as deeply as you can) in through your nose, hold it for just a second or two, then release it as slowly as you can out through your mouth. Do this until your breathing slows. As for the inhaler, if it's Albuterol, it's a rescue inhaler that should work in 15 minutes or less. Others, like Atrovent and Advair, are preventatives that take several days worth of usage to work, and are meant to prevent, not treat an immediate attack.

Hope all is better now, and that you had a good time in the race...

:) Melissa