Can the Heart Muscle Get Tired?

The heart is a muscle, needs oxygen and has no real anaerobic capacity to speak of. It does a great job of sponging up lactate from skeletal muscle. The beating heart is actually helping to mop up lactate as we produce it during high intensity exercise but it's super sensitive to oxygen availability. So if you despite all your good intentions of exercise, if you have coronary blockage, well, that can create problems for the heart.