Esmolol manuscript accepted for publication in the Journal of Applied Physiology.

We used cycle ergometry exercise and infusions of isoproterenol and epinephrine to test the heart rate- lowering effect of esmolol compared to propranolol and saline in healthy humans. Collectively, our data indicate that infusing ~160 mg of esmolol (range 110 to 200 mg in the 5 minutes prior to exercise) acutely and selectively blocks β1 adrenergic receptors. These infusion parameters can be used in future experiments to evaluate β1 versus β2 control of the circulation in humans.