Unclebeets,
I can only speak from experience. I was on Avodart for about four months. At first, I didn't see any difference in strength or indurance. After about three months, I noticed that I was not as strong as before and and was loosing muscle definition. I gave up the Avodart. Now, about two monts later, I am starting to see the trend reverse. Was it the Avodart? I can't say for sure, but I'm not going back to it to find out.