Decide Once: How to Save Your Mental Energy and Actually Get Things Done

Do you feel like you're in a daily battle with your to-do list?

Wondering why you're so worn out by the evening, even on the days you don't feel like you've achieved that much?

You might be experiencing an energy leak you've probably never noticed and once you see it, it's very hard to keep on ignoring it.

I think you'll be surprised when I share this with you because.., it usually isn't the doing that wears us out.

It's the deciding.

All that quiet back-and-forth we have with ourselves about things we haven't even started yet.

It's exhausting, it's invisible, and most of us have no idea we're doing it.

It showed up this week when I noticed that three different clients said a version of the same thing to me, in three separate conversations.

And when something comes knocking three times in a week, I've learned to pay attention.

Each of them had discovered that they were spending an enormous amount of energy not on doing a particular thing, but on repeatedly deciding whether to do it. And when they stopped re-deciding, and simply decided once, something opened up. They got more done. And, more importantly, they felt lighter.

One of them actually stopped mid-sentence and said: "oh... of course. I've taken the question of whether I'm doing it or not completely out of the picture!"

I could hear the surprise in her voice, as though she'd been given permission to stop doing something exhausting that she hadn't even realised she was doing.

This Isn't About Willpower

Let me be clear from the start about what this is and isn't.

On the surface, 'getting things done' can sound like another more-discipline, more-hustle, pull-your-socks-up conversation. It really isn't. That's not very me. If anything, it's the opposite.

This isn't about summoning more willpower. It's about arranging things so you need less of it, removing the decision rather than white-knuckling through it every time.

Because willpower isn't an infinite resource, and most of us in midlife have worked that out the hard way. So think of this as discipline for people who are tired. Which, honestly, is most of us.

Why Re-Deciding Costs So Much

There are two mechanisms worth understanding here, and I do love it when there's something real to point at.

The first is decision fatigue. Making decisions draws on a limited pool of mental energy... every choice is a small withdrawal from the account.

Which is why, by evening, everything feels harder. It isn't that you've become lazy or weak by six o'clock; it's that you've made roughly a thousand decisions since you woke up.

The big ones, the small ones, what to wear, what to reply, what to cook, where everybody's socks are, whether to go to the gym, they all come out of the same little purse.

The second idea is the interesting one: what an undecided thing does to your mind while it stays undecided. There's a concept sometimes called the Zeigarnik effect, which describes how the brain holds on to unfinished or undecided things.

It keeps them open, runs them quietly in the background, and nudges you:

have you done it yet?

Are you going to?

What about now?

Like a tab left open on your computer, using up processing power even when you're not looking at it.

So an open decision, say, whether you'll exercise today, isn't a one-off cost.

Your brain asks it again and again, all day. Each time, another small withdrawal, another flicker of that open loop. It's genuinely tiring, and mostly we don't notice it happening.

And we wonder why we so often feel inexplicably worn out.

That loop doesn't close when you do the thing. It closes when you decide to do the thing.

The relief comes from the decision, not the action which is wonderful news, because it means you can close the loop first thing in the morning and stop paying the tax all day.

This matters even more in midlife and through menopause, when many of us are already working with less capacity than we're used to. Every loop you close is capacity handed back to you to spend however you like.

That's not an indulgence... it's good housekeeping for a stretched system.

The Tool: If-Then

The main tool is beautifully simple. In the research it has a slightly clunky name... an implementation intention, but you don't need the name.

The shape is what's most helpful here: if this, then that. You decide in advance what you'll do in a given situation, so that when it arrives, there's no deciding left to do.

And this is one of the most well-evidenced tools in all of behaviour change, a genuinely large body of research shows people who make an if-then plan follow through far more often than those relying on good intentions alone.

This isn't another life-hack I read on a mug. This has some pretty decent evidence behind it.

Here's how it looked for one client.

She'd been going back and forth about morning workouts, some mornings she made it, some she didn't, and either way she spent a chunk of the day negotiating with herself.

So we made a simple if-then: if I don't get to the gym in the morning, then I go in the evening.

That was the whole intervention. And she came back genuinely surprised, not just that she was doing more (she was), but that she'd stopped spending all that energy deciding. She'd taken the question out of it. No longer up for debate each morning. Just decided.

Removing the Daily Battle

A second example, a different flavour.

Another client, a single mum with two young children, juggling an enormous amount, her energy for daily decisions understandably precious.

She didn't want to track her food day to day; it took up too much bandwidth, and honestly daily tracking isn't something I tend to encourage, and for many people it isn't the right thing. But she used a tracking tool completely differently.

Instead of logging every day, she used it once, as a planning tool.

She sat down and built a library of meals she knew worked for her, ones she enjoyed, that suited her family, that fit roughly what she was aiming for and then she was done.

When it came to it, she simply chose from things she'd already decided were good.

All that daily deliberation, what shall I make, is this okay, what about the kids, what have we got in, evaporated, because she'd done the deciding once, in a calm moment, rather than reopening the loop every evening at the most tired part of the day.

The same tool a lot of people use anxiously, used instead as an act of forward kindness to herself.

My Own Version (The One With the Biscuits)

Here's one of mine, from a good while back, that genuinely changed things with a twist I didn't see coming.

This was when I was establishing a new baseline, and some fat loss was part of it.

My lunches were an afterthought, often a cheese sandwich, grabbed without much thought. If I'm honest, I was also trying to eat as little as possible earlier in the day to 'save' calories for the evening. So I'd come home to cook tea from scratch: tired, hungry, decision-account already empty.

So I made one small change: when I cooked my evening meal, I'd cook an extra, balanced portion for the next day's lunch. That was it. And I want to be careful here, because I'm not telling you what to eat or preaching meal prep, the interesting part was never really about the food.

Because what surprised me wasn't lunch. It was my evenings. I'd come home noticeably more grounded, less frazzled, less heightened after a busy day in the NHS.

And I stopped raiding the cupboard for biscuits while I stood there deciding what to make for tea.

When I looked at why, it wasn't willpower and it wasn't the food. It was that I'd arrived home already nourished and steady, instead of ravenous and depleted, facing a pile of decisions at the exact moment I had least capacity to make them. The biscuits were never a willpower failure, they were a decision-fatigue-and-low-blood-sugar moment, effortlessly solved the evening before, without me even realising that's what I'd done.

The Guardrail: Don't Become a Slave to Structure

This is the part I really don't want you to miss, because without it everything above can curdle into something rigid and unkind, the opposite of what I mean.

The whole point of removing a decision is to serve you.

The moment the structure stops serving you and starts running you, it's no longer doing its job.

Our habits, routines and rituals are meant to hold us, not imprison us. If your if-then has become a stick to beat yourself with, we've taken a wrong turn.

Here's how I keep my own kind. I have a recording day, but my energy varies, as I believe everyone's does, and those of you in midlife right now will know exactly what I mean.

So rather than forcing one fixed time and feeling like a failure if I'm not up to it, I book two slots, early and later, with a simple if-then. If I wake raring to go, I record early and the rest of the day, including that later slot, gets to be restful. If I need a slower start, a longer breakfast, gentle admin, I take it and record later instead.

Both options are already decided. So I never force myself to perform when I'm not ready, but I also never carry that nagging open loop of I'm behind, I should have done it by now. Whichever way it goes, it was already the plan.

There's no failure available to me.

I've pre-decided a flexible structure, and the flexibility is the whole point.

That's the difference between a structure that frees you and one that traps you: a good pre-decision leaves room for you to be a human being with variable energy. It removes the deciding without removing the compassion.

How to Try It: Make It Unfailable

If you'd like to try this (and I hope you do, because it sounds almost too simple until you feel the difference) keep it small, and make it unfailable.

BUT...

Don't systematise your whole life this week; that's just decision fatigue wearing a different hat.

Pick one thing.

One recurring decision you keep having to make that quietly drains you.

The gym.

What's for tea.

When you answer emails, or take your supplements, or how you handle that one text you keep leaving unread.

Make it an if-then, in advance, in a calm moment. Write it down if it helps. And then stop leaving it open. Let it be decided, and notice, over the next week, whether closing that one loop gives you back more energy than you expected.

One loop. That's all. See how it feels, and go from there.

Why This Is Really About Presence

You might reasonably wonder what if-then plans and batch-cooked lunches are doing on a podcast called Rooted in Presence. Here's the connection, and it's the thing I'd most love you to take away.

Every open loop, every undecided thing running quietly in the background, is a little piece of you that isn't here.

It's off in the future, negotiating with the gym or fretting about dinner.

And you can only be so present in your actual life... in the conversation, the evening with your family, the walk, the cup of tea.... while a dozen tabs are open in the back of your mind demanding to be decided.

So closing these loops isn't really about productivity at all. It's about freeing up the part of you that's been running background tasks, so you can actually be here.

That's what all the deciding-once is in service of... not getting more done for its own sake, but quietening the noise enough that you can be where you actually are.

So this week: close one loop.

Decide one thing.

And notice what it feels like to carry a little less.

If you'd like support building this kind of gentle, sustainable structure the kind that serves you rather than runs you — that's exactly what I do with people, through coaching and the community at Still Space Hull. You'll find everything at carlykillen.com and stillspacehull.com.

May you meet yourself with compassion, walk with presence, and remember, you already have everything you need.