Marabotti et al. (2008 p.293) wanted to isolate the different factors likely to trigger a diving response. Marabotti et al. (2008 p. 294) observed 12 male subjects, who were active divers capable of holding their breath for approximately 4 to 6 minutes, for five different treatments in a 10 meter pool. Treatments included subjects out of the water with only the subjects' heads out of the water while breathing, fully submerged near the surface of the pool while breathing through a snorkel, fully submerged near the surface of the pool while holding their breath, and diving 5 meters into the pool while also holding their breath (Marabotti et al. 2008 p. 294). Marabotti et al. (2008 p. 294) measured various cardiac output, stroke volume, heart rate and blood pressure. Although Marabotti et al. (2008 p. 295) found in their results that stroke volume, cardiac output, and heart rate decreased in all of their treatments, with the greatest change in cardiac responses occurring when subjects dove 5 meters into the pool. Water submersion, apnea, and water temperature appeared to have less effect on cardiac responses than pressure at depth (Marabotti et al. 2008 p.296). These results suggest that the pressure caused by increasing diving depth is responsible for triggering the diving response. Although my experiment does not analyze pressure depth as a measure, this study does not completely confirm my results since Marabotti et al. (2008) conclude that cold water and apnea have less effect on the heart. However, Andersson et al. (2002) ¬¬ supports my results that apnea triggers the diving response in humans and the diving response is further increased by practicing apnea in cold water. Andersson...... middle of paper ...... this may have happened because the face was not directly in contact with the cold water. Schuitema and Holm (1988 p. 120) suggest that certain areas of the face are more sensitive to cold water which will trigger a diving response. Their protocol involved 22 untrained divers holding their breath for 30 seconds after a five-minute rest (Schuitema and Holm 1988 p.119). A plastic bag filled with ice was placed strategically and randomly around different areas of the face for five minutes while the subject held their breath (Schuitema and Holm 1988 p.119). The treatment of apnea was significantly different from the treatment of apnea with a plastic ice pack on the forehead and eyes (Schuitema and Holm 1988 p.120). These results suggest that water must be in direct contact with the forehead or eyes to significantly reduce heart rate (Schuitema and Holm 1988 p..120).