I built my whole identity around being a runner. Then my body changed the rules without telling me.
I remember stepping out the front door at the start of a training run, feeling a tightness in my throat about how the next couple of hours were going to go. Would I hit the wall early, or just suffer slowly the whole way? And if a headache came afterwards, how many days would it last this time?
This wasn't supposed to happen. I was a marathon runner. I had done the work. I knew what my body could do. And now, somewhere between turning 40 and trying to celebrate it, my body had become a stranger.
The hardest part wasn't the physical struggle, it was the grief of losing something I had only just found.
I Was Not Someone Who Ran
Let me take you back to where this all started.
Growing up, I was never really drawn towards physical sports. Running at school was always an impromptu 5k one morning, followed by a week of limping.
It was when I was at home with my little ones, in my mid-thirties, that I started to notice runners. People in my neighbourhood; ordinary people (not athletes, not fitness influencers) going from couch to 5k. Something about that ordinariness made me think: could I actually do that?
One day I just went outside and tried.
Couch → 5k → 10k → Full Marathon. The first time I crossed a finish line, I genuinely could not believe my own legs had carried me there!
What Running Gave Me That Nothing Else Had
Running gave me something I hadn't experienced much of before: evidence that I could do hard things if I just took my time and listened to my body. Every kilometre logged was proof. I got stronger, I got faster, I could take on longer distances. My body responded in ways that felt almost miraculous to someone who had never really trusted it before.
I also joined a running club, and for the first time in my adult life made friends around our shared love for something. For someone who always found socializing a bit stressful (always trying to figure out what to contribute to a conversation, where to fit in) having a built-in reason to be around people made it feel so meaningful and almost effortless! The structure of it helped. The fact that we were all there for the run meant I didn't have to figure out whether I truly belonged.
Running became the first thing in my adult life that felt entirely mine. Not a role I was filling, not an expectation I was meeting. Just me, my shoes, my dreams, and the open roads.
By the time I turned 39, I was planning four marathons to celebrate four decades of life. It felt right. It felt like the most 'Nina' thing I had ever done - which, if you know me at all, means it was equal parts ambitious, slightly unhinged, and deeply personal.
And Then I Turned 40
I wish I could pinpoint the exact moment things changed. But that's not how it happened. It was gradual, which almost makes it worse, because gradual means you spend a long time telling yourself it's temporary. That you're just tired. That you need to tweak your training plan. That next week will be different.
The weight started creeping up despite nothing changing in my diet or my training. In fact, the more I trained, the harder everything got. I would go out for a run feeling like I'd taken a full year off. My legs were heavy and slow; my pace dropped; the easy runs stopped feeling easy or good.
I kept trying to push through, making adjustments, troubleshooting, refusing to accept that something might actually be wrong. Because admitting something was wrong felt like losing the one thing I had built for myself.
The more I trained, the harder everything got. That's not how it's supposed to work. That's not how it ever was before.
The Blood Test That Explained Everything (Almost)
Eventually I went to get my blood tested. My ferritin (the protein that stores iron) was in the single digits. Critically low. Lower than it had ever been, even for me (and I've never had particularly high iron levels).
Suddenly everything made sense. The exhaustion that sleep couldn't fix. The headaches. The feeling of running through wet concrete, like my body was dragging itself through something thicker than air. When your ferritin is that low, your body simply cannot perform. It doesn't matter how fit you are or how hard you train; you're running on empty in the most literal sense.
The likely cause? My periods had become extremely heavy as I approached 40, a common but under-discussed side effect of perimenopause. I was losing more blood each cycle than my body could replace before the next one arrived. Month after month, my iron stores were being quietly depleted while I stood at start lines wondering what was wrong with me.
If you're a woman in your 40s whose athletic performance has suddenly and inexplicably declined, please get your ferritin tested. It made all the difference to finally have an answer!
And Then There's the Weight Conversation Nobody Has Honestly
Layered on top of the iron deficiency is something I'm still actively trying to understand: perimenopause.
I went looking for clear answers about my recent weight gain and found almost nothing useful. I tried the obvious search terms. I went down forum rabbit holes at 11pm. I spoke with my family doctor. Some people told me it was simple (calories in, calories out) and implied I must be secretly eating more than I realize. Others recommended extreme approaches: cut all carbs, fast for ten or more hours a day, exercise harder. Nothing that felt sustainable for a real human life, let alone a neurodivergent one, where "just change your whole routine" and "deplete your dwindling energy reserves" is a monumental ask.
Some voices told me that weight gain during perimenopause was entirely within my control. Others said the hormones would win no matter what, and that I should just accept it. Neither answer filled me with hope or gave me anything I could actually use.
What I've since learned is that the stress of intense training on an already depleted body may actually be making things worse. Elevated cortisol from over-exertion, combined with the hormonal shifts of perimenopause, can signal to your body to hold onto weight rather than release it. So the very thing I was using to fight back may have been working against me.
I'm currently backing off the intensity. Focusing on getting my iron levels up through supplements and nutrition. Trying to find a way to stay active that doesn't cost me more than I can afford to spend right now.
I don't have a tidy ending for this story yet. I'm writing it in real time, which means some chapters are still messy and unresolved.
Where I Am Now
I still call myself a runner. Even on the days when running feels impossibly far away. Because the identity isn't just about the kilometres; it's about who I became out there on those roads. The woman who found out she could do hard things. I'm not ready to let go of her.
I also lost something I haven't fully named until now: the community. The running club Sunday mornings, the people who knew me as a runner, the shared language of training plans and snacks to stay fuelled. When your body stops cooperating, you quietly disappear from those spaces, and that has its own kind of grief.
But I'm also learning, slowly and imperfectly, that taking care of my body now might look different from what it looked like before, that rest is not the same as giving up, and that listening to what my body needs right now is not a betrayal of everything I built.
I don't yet know what my running life looks like on the other side of this. I don't know if I'll run another marathon. I don't know if I'll get my ferritin levels up quickly or whether this will be a long, slow climb back. I don't know if I'll ever fully understand what perimenopause is doing to my body or find an approach to managing it that actually works for me.
What I do know is that I'm not done figuring it out.
And if you're somewhere in this story too (if you recognize the confusion, the frustration, the grief of a body that seems to be rewriting its own rules) I hope you know you're not alone in it. We're figuring this out together.
— Nina
If this resonated, I write honestly about active living, neurodivergent brains, and the mess of midlife at ninaryan.ca. Find me there, or »subscribe here« to get new posts straight to your inbox!