I am a 25 yr. old healthy male, 5'9" 165lbs. At the age of 24 I was diagnosed with 2nd degree heart block, Mobitz 1, aka Wenckebach block. I am asymptomatic, other than the fact that I can feel my heart skip occasionally. I've seen a cardiologist three times since diagnosed. He's reassured me that I am fine and can continue to exercise regularly. He told me that Mobitz 1 is generally a benign form of Heart block and will not progress to the next level. Being a 25 years old w/2 kids, I am deeply concerned with my health and am just looking for reassurance from another source. If I continue to exercise reguarly and do cardiovascular exercise, can my heart block progress? Can I possibly do "too much" cardio? Also, how do I ask my doctor for a second opinion without feeling like I am questioning his intelligence? Im not real sure if I need a second opinion, I've seen the same cardiologist three times and I feel pretty good about his knowledge. Any reassurance would be appreciated, thanks.