Utilization of Non-Invasive Maximal Gas-Exchange Measurements to Estimate Cardiovascular Performance

ABSTRACT Introduction A non-invasive measurement of arteriovenous difference (a-vO 2 D), equal to oxygen intake, might allow for the calculation of stroke volume (SV) and cardiac output (CO). Increasing SV and CO in athletes may improve work production and performance at a given heart rate. This study used gas measurements from a standardized cycle test to non-invasively quantify cardiovascular function and compare sex differences. Methods Forty-five participants (23 males, 22 females) performed a 3-min all-out (3MT) cycle test to determine metabolic gas measurements. During the initial visit, participants determined the maximum resistance sustainable for their cycle test. After establishing their cycling cadence for an initial 10 s, each participant pedaled for 3 min at a tempo equivalent to 50% of their maximal resistance. In minutes 3–6, participants cycled to their maximum resistance. Participants returned to their 50% maximum resistance for the final 3 min. Results The linear regression for maximum oxygen uptake (V̇O 2max ) and a-vO 2 D for males and females combined were statistically significant ( P < 0.001). The linear regression for a-vO 2 D and oxygen pulse (OP) for all participants ( P < 0.001) and males were significant ( P = 0.01), but not females ( P = 0.75). The linear regression for V̇O 2max and OP were statistically significant for all participants ( P < 0.001) and males ( P = 0.03), but not females ( P = 0.85). Statistically significant differences were observed between males and females in SV, CO, and V̇O 2max of 42.6%, 41.0%, and 7.9%, respectively ( P < 0.001). Conclusion A non-invasive evaluation of cardiovascular functioning is feasible and might provide quick and accessible information on variations in training response across sexes.