Effects of a Demand-Valve SCUBA Regulator on Cardiorespiratory Response During Submaximal Exercise Under Normobaric Conditions: A Preliminary Investigation

SCUBA diving fatalities are often related to cardiac events triggered by stress linked to equipment. The purpose of this investigation was to examine the effects of a SCUBA regulator on cardiorespiratory exercise at a submaximal workload. Ten participants (mean = 21.5 yrs; s.d. = 1.16) completed two submaximal exercise tests at 1 ATA; one while breathing normally and a second while breathing directly from a demand valve SCUBA regulator. Total time to test completion (TOT), heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), and arterial oxygen levels were all assessed. No significant differences between conditions were found for measures of TOT, heart rate, blood pressure, RPE, and arterial oxygen measures. Statistical analysis suggested that use of a SCUBA regulator itself did not affect exercise tolerance or increase cardiorespiratory stress at submaximal workloads. Several anecdotal observations in HR, BP, TOT, and RPE responses suggested further research is warranted.