@frane Your diminished running speed makes sense. I was advised that Metoprolol and other beta blockers are designed to lower the heart rate. That means when exercising aerobically, your heart will not be able to deliver the additional oxygenated blood your body needs to perform. As a result of this, I was unable to continue in an exercise class which was designed to get our heart rates up. I was winded and had muscular fatigue when trying. I dropped out and now do stretching and the occasional weights.