The negative impact the SCBA has on VO2max; researchers have studied various methods to alleviate this problem. One means of improving VO2max is through high intensity interval training (HIIT) (Gormley et al., 2008; Wisloff et al., 2009). Changes in both lung and cardiac function have been associated with the improvements in VO2max (Helgerud et al., 2007). Recently, Dreger and Paradis (2011) and Paradis and Dreger (2011) reported the effect of HIIT while breathing from an SCBA. Their study showed significant improvements in performance, pulmonary and cardiovascular function that was significantly greater than HIIT training without the SCBA. However, the cost of an SCBA is approximately $3,500 with air supply being an additional gdisposableh cost. This may be cost prohibitive to for smaller fire departments and those preparing to go into the fire trade. On the market there are a number of devices that restrict breathing, however many of them are used during sitting and not during exercise. Recently, a device has been developed to be used during exercise (Training Mask LLC, Cadillac, MI). The Elevation Training Mask provides variable breathing resistance, which may simulate the SCBA. However, there has not been any scientific study of the ETM nor its effects relative to the SCBA. The purpose of this investigation was to examine the effect of the Elevation Training Mask while performing HIIT.