All of a sudden I can't ride for any more than 3-4 miles before being totally wiped out on both my mountain bike and my Madone. My thighs start burning and aching after about 5 minutes. By mile 3 I'm out of oxygen. This started last week and into this week. My saddle no longer seems to fit as yesterday I discovered chaffing and I had only done 3 miles. I have a Brooks B17 Narrow.

Before I was doing 6-10 miles without any problems except my arms/shoulders hurting and figured it was just lack of upper body strength. Now my upper body is fine but my legs are a mess.

My body just wants to sleep it off. I didn't even get up today until 2pm.

I haven't fallen off in two weeks which is a wonderful thing.

Just a rough patch in cycling or is something up?