The brain efficiently utilizes dominant templates to think, learn, create, solve problems, and communicate. Many studies have shown that individuals perform better if not wearing a respirator than with wearing a respirator. This study examined the degree of performance reduction attributable to specific dominant character traits. The subjects performed on a treadmill at a constant speed and grade resulting in 80-85% of maximum oxygen consumption (VO2max). A modified M40 respirator was used to create three levels of inspiratory resistance: 2.78, 16.79, and 27.27 cmH2O*(sec/L). The 31 subjects were tested using a Myers-Briggs Type Indicator (MBTI) and State-Trait Anxiety Inventory (STAI). Multiple regressions and an ANOVA were used to test for correlation. When air intake is very constricted, the multiple regression that was found to be statistically significant was sensing-intuition (how one takes in information) and thinking-feeling (how one makes a decision) versus performance time with 27.27 cmH2O*(sec/L) inhalation resistance.