The Tiredness Is Different. Here's What Nobody Tells You.

My Garmin watch has a feature called Body Battery. It tracks your heart rate variability overnight and produces a score between 1 and 100 that represents how recovered you are. A good night's sleep might give you an 80. A broken one — the kind where you're up at 2am, then 4am, then 5:15 when someone decides it's morning — might give you a 32.

I have not seen 80 in about two years.

Last Tuesday I woke to find I'd scored a 28. I showed it to Claire over breakfast. "That's not a body battery," she said. "That's a smoke alarm running low."

She's a secondary school art teacher. She's also running on a 31 most days. We are two people held together with caffeine and the fact that we find each other funny.

But here's the thing I want to talk about, because nobody said it to me clearly before Ellie arrived: the tiredness you experience as an older parent is not simply the same tiredness younger parents experience, administered in the same quantities. It is qualitatively different. It metabolises differently. It stays longer and goes somewhere else when it leaves.

At 30, tiredness is an inconvenience. At 44, it is a negotiation.

The physiology, briefly

I am going to make you read a small amount of biology. I will keep it short and I will not use the word "hormesis."

After the age of about 40, several things change in how your body handles sleep deprivation and physical stress. Testosterone levels decline — not dramatically, but meaningfully — which affects recovery rate and the ease with which you rebuild after exertion. Cortisol regulation becomes less efficient, meaning stress hormones linger longer in the system after a disrupted night. Growth hormone, which your body releases in the deep phases of sleep, has less opportunity to do its repair work when those phases are constantly interrupted. Your circadian rhythm becomes less elastic, less able to absorb the chaos of waking at 4am for weeks at a time without accruing a kind of biological debt.

None of this is terminal. None of it means you cannot function, or cannot be a good parent, or cannot be present and useful and alive to your children.

It does mean that the playful article headline "sleep is for the weak!" is not aimed at you.

The difference between tired and depleted

There are two distinct states I have learned to distinguish.

The first is ordinary tiredness. You are tired. You need sleep. Sleep, when it comes, fixes it. You wake up feeling like yourself again, or close enough. This is the tiredness described in every parenting book, the one they warn you about. It is real and it is unpleasant but it is also, crucially, reversible.

The second is depletion. This is what happens when the ordinary tiredness runs long enough and deep enough that sleep alone stops being sufficient. You sleep — or what passes for sleep in a house with a toddler and a two-year-old — and you wake up and you are still tired. Not groggy-tired, not need-another-coffee-tired: fundamentally, persistently, molecularly tired. The recovery mechanism is broken. There is no amount of early nights that are going to fix Thursday by Friday morning.

I have spent significant portions of the last four years in the second category. I suspect most older parents have.

The crucial difference is not the volume of sleep lost. It is the baseline from which you are losing it. At 30, you are recovering from a position of relative surplus. At 44, your reserves are smaller, your recovery rate is slower, and the same disruption hits harder and sticks longer.

What I have actually found useful

I want to be specific here, because most advice about sleep deprivation is aimed at people who could, in theory, just go to bed earlier. We cannot always just go to bed earlier. We have jobs and partners and children who have decided that 5:15am is a reasonable start to the day.

Non-negotiable sleep blocks. I protect a window. Not always successfully, but deliberately. I have accepted that I will not get eight hours. I try not to get fewer than five consecutive hours as a floor. When Sam has a bad week, this is aspirational rather than achievable, but the intention matters. It means I am not also staying up until midnight watching television out of an instinct to reclaim the evening.

The two-thing rule. On depleted days — Body Battery under 35 — I try to do two things well and stop trying to do everything adequately. Two things get full attention. Everything else gets done sufficiently or gets moved. This is genuinely hard for someone with a freelance business and a schedule, but it is less hard than the alternative, which is doing everything at 60% capacity and wondering why the work feels hollow.

Caffeine timing. I cut coffee at 1pm. I know everyone says this and it feels like a very small and boring intervention. It is not. Caffeine has a half-life of five to six hours, which means a 4pm coffee is still half-active in your system at 9pm, when your hypothalamus is trying to send the "time to sleep" signal. On the weeks I adhere to this I fall asleep faster and the sleep I get is better quality. The Garmin confirms it. I resent the Garmin for being right.

Walking. Not running, not the gym — I'll cover my complicated relationship with exercise in another post. Walking. Twenty minutes, usually after lunch when I can, sometimes before school drop-off. The research on walking and cortisol regulation is solid. It is not glamorous. It is the most consistent useful thing I have done for my energy levels in four years.

Iron and B12. I had blood tests at 42 because I was tired in a way that felt wrong even given the context. My iron was low. My B12 was borderline. These are the kinds of things that do not announce themselves dramatically; they just make everything slightly harder than it should be, a few percent, consistently. Get your bloods done. Particularly if you are tired in a way that sleep does not touch.

The thing worth saying clearly

This is not a complaint. Sam and Ellie are not the problem. The problem, to the extent there is one, is that I assumed my body would handle early parenthood the way it might have handled it a decade ago. It doesn't. It handles it differently, and the adjustment required — in expectation as much as in practice — is real.

What I have come to believe is that older parents are not weaker. We are operating on different parameters. The parents at the antenatal class who were 31 will recover faster from a bad night. They will bounce back in a way that I do not entirely bounce anymore. I no longer bounce. I absorb.

But absorbing is not nothing. There is something in the longer recovery that forces you to be more deliberate, to choose more carefully, to spend your limited energy on the things that matter. I notice my children more carefully than I think I would have at 30, not because I am a better person but because I have less capacity to be elsewhere. The depletion focuses the attention.

My Body Battery this morning was 41. Sam slept through until 5:45. I have already had my walk. It will probably be a good day.