cardio UK /ˈkɑː.dɪ.əʊ/US /ˈkɑɹ.di.oʊ/adjective 1noun 1forms 1 adjective1 •Cardiovascular; pertaining to the health of the circulatory and respiratory systems. noun1 •Exercise with the goal of raising the heart rate by walking or running on the treadmill.I did some cardio today instead of lifting weights. formscardios
