Cheers guys...
I'm getting that I need to watch what I am doing and not to over do it. I am a big heavy guy, just under 22 stone at the moment. Not done much exercise or training for over 20 years. So I guess, I need to take it easy to begin with.
Going to just do a few miles every other evening on my MTB, there is a nature reserve 2 minutes from where I live. Great to just thrash about in.....puddles and muck! Brilliant! And do as Evonhess suggested, one long ride a week. Will see how that works out for me.
Great advice guys, cheers!!!
Will let you know how I get on.....