Everything you need to know about photoplethysmography (PPG), the technology behind heart rate measurements in fitness watches and smart rings. When you purchase through links on our site, we may earn ...

Dr. Paul Friedman answers the question: 'Heart Block versus Artery Blockage?' — -- Question: I have been diagnosed with heart block. How does this differ from blockage in one of my arteries?

Rowing machines and treadmills do not challenge your cardiovascular system in the same way, so what is the science behind it? When you purchase through links on our site, we may earn an affiliate ...