If you’d asked me twenty years ago how to stay slim and healthy, I’d have said the same thing most of us were taught: move more, eat less, do your cardio. Run, spin, step — burn it off. And for a while, in our twenties and thirties, that seemed to work well enough.
Then midlife arrives, and the old rules quietly stop working. You’re doing everything you always did — maybe more — and your body responds by doing the opposite of what you’d hoped. If that’s you, I want you to hear this clearly: you’re not doing it wrong. The advice was wrong for this stage of your life.
What actually changes after 45
From around our mid-forties, falling oestrogen changes the game. We lose muscle faster, we lose bone density faster, and our metabolism shifts. Muscle is metabolically active tissue — it’s part of what keeps your metabolism ticking over — so as it quietly declines, everything you’re trying to manage gets harder.
Here’s the part that matters: cardio, for all its benefits for your heart and mood, does very little to protect muscle and bone. You can run every day and still lose the very tissue that keeps you strong, upright and independent. That’s why so many women in midlife feel like they’re working harder than ever for less and less return.
Why strength wins now
Strength training — lifting something challenging, a couple of times a week — is the single most effective thing you can do about all of it. It signals to your body to keep the muscle you have and build a little more. It loads your bones, which is how bones stay dense. And more muscle means a metabolism that works with you rather than against you.
It’s not about becoming a bodybuilder or living in a gym. It’s about being able to carry the shopping, get up off the floor, catch yourself if you stumble, and feel capable in your own body for decades to come. That’s what strength training buys you after 45 — not just a look, but a life.
But isn’t cardio still good for me?
Yes — and I’d never tell you to give it up. Walking, swimming, cycling, dancing: all wonderful for your heart, your head and your energy. Keep them. The shift I’m asking you to make isn’t cardio or strength — it’s adding strength as the priority, rather than relying on cardio alone to do a job it was never able to do.
If you’re time-poor (and who isn’t), and you can only add one thing, make it strength. Two short sessions a week will change more than an extra cardio class ever could.
Where to start — small
Here’s where I want to save you from yourself, because I know the temptation is to go enormous. Please don’t. The women I coach who are still training at Christmas aren’t the ones who went hardest in week one — they’re the ones who started small enough to keep going.
Two short strength sessions a week is plenty to begin. You don’t need a gym: a pair of dumbbells, resistance bands, or even your own bodyweight will do. Squats, a row, a press, a hinge, a bit of core — the basics, done consistently, are what work. Add a little weight over time, and let it build.
That’s genuinely it. Not punishing. Not complicated. Just consistent.
The reframe that changes everything
After 45, fitness stops being about shrinking yourself and starts being about building yourself. Less punishing, more capable. It’s a kinder philosophy, and — happily — it’s also the one that actually works for a midlife body.
So if you’ve been running yourself into the ground with cardio and wondering why nothing’s shifting, try putting that energy into strength instead. Give it a few weeks. I think you’ll be surprised how much better — and stronger — you feel.
Marleen Konijnenberg is a pharmacologist and Women’s Health & Fitness Coach, and founder of FemVital. Her self-paced 6-week course, Strong Through Menopause, helps women build strength that lasts — starting small, and keeping going.
General information, not medical advice. Check with your GP before starting new exercise if you have a health condition.