Back to Back -- Long

I'm getting a bit excited -- knock on wood . . .  Each of the last three weekends, I've managed to do a long workout both Saturday and Sunday.  It's making a difference.  First I ran 15 and rode 50.  Then I ran 14 and 17.  This weekend I ran 20 and then biked 40.  Suddenly it feels like I've turned a corner, from my long struggling comeback to actually feeling pretty fit.  Today I hit the track, and it was sort of fun.  I've never actually said that before.  I hate track work. It hurts . . .  But today I went with a moderate aspiration, to do 400, 3x800 and 400.  I wanted to get my 400s down to 90 seconds, which I haven't been able to do for a while, and then I wanted to run the 800s at Yasso pace of 3:40.  The good news was that I made my times on the 400s and actually went too fast on the 800s, hitting between 3:17 and 3:23, and getting my heart rate into a zone I haven't seen in a while . . .  Maybe I will actually be able to run a sub-4 hour marathon in 7 weeks . . .