Why do I get so exhausted from running?

I'm a 36 year old male, workout regularly and am in pretty good shape. I'll train with weights, spin, etc., and though I "feel it" the next day, it's not too bad, and I'm usually good to go again, my recovery is quite good. However, when I run outside (jog), I feel 10 times exhausted the next day, my ankles are sore, and overall, I feel WIPED OUT (coma feeling). Is there anything I can do to remedy this? I only run for 20 minutes, and yet I still feel it so much the next day that I almost feel like I need another day off. Is it because my body isn't used to the running, or, is my body asking me to slow down? Is it aging? When I was 23, I could run 1 hour everyday and hardly feel it the next day. Part of this has to do with aging I'm sure. Is there anything I can do to boost my next day recovery? I want to exercise 40 minutes per day (weights and running), but I don't want to feel wiped out the next day.