Cardiovascular and Metabolic Responses to Treadmill and Elliptical Exercise

Timmons, K., Mason, S., Peterson, M., Venters, E., Hoover, K., Crehan, L., McCole, S.D., and McKenzie, J.A., Department of Exercise Science & Physical Education, McDaniel College, Westminster, MD Purpose: The current study’s purpose was to compare the cardiovascular and metabolic responses to a maximal treadmill and maximal elliptical exercise test. Methods: Healthy, physically active females (n = 10) and males (n = 10) each performed a VO2max test on a treadmill and on an elliptical, on separate occasions, at least 48 hours apart. To be considered a VO2max, participants had to attain at least 3 of 5 standard maximal test criteria. Each test was preceded by 10 minutes of quiet rest for measurement of baseline values. Every 15 s throughout the test, VO2 and respiratory exchange ratio (RER) were measured using the ParvoMedics TrueOne metabolic measurement system, whereas cardiac output (Q), stroke volume (SV), and heart rate (HR) were assessed every 10 s using the PhysioFlow Enduro impedance cardiography system. Rate of perceived exertion (RPE) was reported at the end of each test stage, and blood pressure (BP), via the Tango+ Automated BP Monitor, was measured at the end of the test. A finger stick blood sample drawn 2 minutes post-test was used to determine blood lactate. Mean arterial pressure (MAP), arterio-venous oxygen difference (A-VO2D), and total peripheral resistance (TPR) were calculated using standard formulae. Peak values were analyzed for significant differences (p \u3c 0.05) using paired samples t-tests, ANCOVA, or nonparametric tests, as appropriate. Results: Data are reported as means ± SEM. Participants averaged 23 ± 1 yr, 78.3 ± 4.5 kg, and 1.73 ± 0.02 m. With the exception of systolic BP (129 ± 3 vs. 123 ± 2 mmHg; p \u3c 0.05), resting values did not differ on the testing days. Peak values for HR (196 ± 1 vs. 192 ± 1 bpm; p = 0.001), VO2 (49.8 ± 2.0 vs. 44.7 ± 1.9 mL/kg/min; p \u3c 0.001), systolic BP (174 ± 6 vs. 156 ± 5 mmHg; p \u3c 0.05), and MAP (98 ± 3 vs. 88 ± 3 mmHg; p \u3c 0.001) were higher during the treadmill test than during the elliptical test. In contrast, RER was higher during the elliptical test than the treadmill test (1.21 ± 0.01 vs. 1.16 ± 0.01; p \u3c 0.001). All other variables were similar between the tests. Conclusion: Although participants met at least 3 of the standard criteria for a VO2max test, the results from the treadmill maximal exercise test were slightly different than those obtained via an elliptical maximal exercise test. Research supported by the McDaniel College Student-Faculty Collaborative Summer Research Fun