This paper updates our continuing research program examining the physiological performance of professional race car drivers. Data is presented from a comparative study examining the heart rate of different drivers in the lndy Lights race series. Each driver was monitored during practice, qualifying and race sessions on a short oval track (one mile) and a road course track. The effect of track type on physiological performance are addressed. Physiological data recorded during the Indianapolis 500 race and from practice and qualifying sessions for this event are shown. Technical difficulties involved in accurately measuring heart rate (HR) in the race car environment are addressed.