I had radiation treatment in 2010 which has left me with only half a thyroid gland. The side effect of this is that I am on a thyroid replacement therapy of daily tablets of thyroxine. My levels are spot on.
I am currently training for a half marathon in May and things have been going very well. I am using the asics plan and up until now have been having a great time on it.
I am only running twice a week as I am also training for a Swimathon in April of 2.5km. I am fitting in watt bike training when I can so I can keep my triathlon fitness going while training for the HM.
I have hit a brick wall this week. The running plan went from 7km runs to two 10.5km runs. The first one was great but my appetite completely dropped off after the run. I had a terrible time trying to eat as I felt it was the last thing I wanted to do. The second run left me in the gutter. No energy, aching all over and just generally feeling rubbish. It was like I had become hypothyroid overnight. To add injury to insult overnight I put on 3lb.
I have done some reading and it looking like even though my joints, muscles and brain was ready for the increase my metabolism wasn't. I seems it treated like I was under stress and the thyroid is not one of those glands that works at its best while under stress. It just seems to hibernate.
I have had two days off exercise and rested. I spent yesterday fuelling up with healthy good stuff and today I feel fit to go again.
My problem is I am supposed to be doing another 10.5km run and then on to 14km next run. I don't think that is a good idea.
I was thinking about going back to 7km and building up 1km a week, maybe my body can cope with that. So I would do 1-7km run a week and the increased Km run then a swim and watt bike session if I had the time/energy.
Any help or thoughts would be greatly appreciated.