Last week I was told that my thyroid is now underactive. Not welcome news, but it does explain what I’m currently experiencing.

Eighteen months ago, my body was in overdrive. My heart raced, my weight dropped, and my strength disappeared. Now, following treatment, everything has shifted in the opposite direction.

Same body. Different conversation.

Whilst not welcome news, it does explain a number of ‘minor’ issues I’ve been experiencing:

• Puffy, watery eyes — which I had reluctantly put down to ageing.
• Pain in my sacroiliac joints, radiating down my legs. I’d put this down to inactivity over the winter – avoiding cold, wet runs and, if I’m honest, using my dissertation as an excuse.
• Difficulty losing weight, despite doing what would normally work. I’d intentionally sought to build muscle before Christmas. I was successful but haven’t been able to lose the fat that accompanied it. 
• Slightly abnormal kidney function results, which didn’t quite add up. My GP surgery raised concerns about my kidney function, which didn’t fit with how I felt at all.
• Higher than usual blood pressure. Still within a normal range, but high for me.
• A lower resting heart rate than expected. I normally have a resting heart rate of below 60 bpm but I would have expected it to rise during a period of low activity.
• A persistent low mood. 

On reflection, the signs were there. But I had convinced myself that the radioactive iodine treatment last September had closed this chapter. Even though I knew there was a strong possibility it would lead here.

Having an underactive thyroid feels very different from an overactive one. I don’t feel unwell, but I don’t feel right. With an overactive thyroid I was physically unable to lift heavy or run. Now I can – but doing so could lead to overtraining or injury. I have to manage my energy more carefully. Training needs to be smarter, not harder.

For now, that means:

• No chasing PBs.
• No charging up hills.
• Accepting that weight loss may need to wait. I need to  focus on not gaining too much.

Over the last few years, despite developing Graves’s Disease, recovering, relapsing, and having a ‘permanent’ treatment, I’ve built my strength and endurance. I’m now stronger than I was at 60. I’ve completed four Hyrox competitions, run a half marathon, walked the Surrey Peaks, and climbed Carrauntoohil. So I know what I’m capable of – even while navigating a health condition.

I’m hoping that this will be the final phase of a long (nearly 5 years) journey. I’ve seen others come through this. I have a couple of friends with the same condition who have gone from having an overactive thyroid, through treatment, to stability with medication.

So whilst this is another adjustment, it also feels like a step forward. I’ve still got a lot I want to do.

I’m not done yet.