Something shifts in your 40s. It’s subtle at first — a bit more fatigue, a bit more weight around the middle that wasn’t there before, a sense that your body isn’t quite responding the way it used to. And then one day you realise: the approach that worked for the last two decades has simply stopped delivering.

If that’s where you are right now, I want to start by saying this: you are not imagining it, and you are not doing anything wrong. Your body genuinely is changing. The question is not how to force it back into behaving like it did at 25 — it’s how to adapt your approach so it works for the body you have now.

I’ve been through this myself. As a former GB athlete who has spent decades training, competing, and coaching, I can tell you that my body at 50 is a very different animal to my body at 30. And the sooner I accepted that, the sooner I stopped fighting and started thriving.

What actually changes in your 40s

Your 40s bring a convergence of physiological changes that collectively shift how your body processes energy, stores fat, and responds to exercise. None of these on their own are dramatic, but together they can feel like the rules of the game have changed overnight.

  • Hormonal shifts. For women, perimenopause typically begins in the mid-40s, bringing fluctuating oestrogen and progesterone levels that affect metabolism, fat distribution, mood, sleep, and appetite. For men, testosterone gradually declines, affecting muscle mass and energy.
  • Muscle loss. From your 30s onwards, you lose roughly 3-8% of your muscle mass per decade if you’re not actively maintaining it through resistance training. Since muscle drives your metabolic rate, less muscle means fewer calories burned at rest.
  • Metabolic slowdown. Your basal metabolic rate naturally decreases with age — roughly 1-2% per decade. Combined with muscle loss, this means your body needs less energy than it once did.
  • Recovery takes longer. Your body’s ability to recover from intense exercise diminishes. Workouts that you bounced back from easily in your 20s now leave you stiff, tired, and needing more rest.
  • Sleep changes. Sleep quality often deteriorates in your 40s, particularly for women in perimenopause. Since poor sleep directly affects hunger hormones, cortisol, and metabolic function, this has a cascading effect on weight.
  • Stress accumulates. By your 40s, most people carry significant responsibilities — careers, children, ageing parents, mortgages. Chronic stress elevates cortisol, which promotes fat storage and disrupts everything from digestion to immune function.

Hormones, metabolism and the midlife shift

I’ve written in detail about perimenopause and weight gain, so I won’t repeat everything here. But it’s worth emphasising that the hormonal changes of midlife don’t just affect your weight — they affect your entire relationship with your body.

Declining oestrogen changes where your body stores fat, shifting it from hips and thighs towards the abdomen. This “midlife middle” isn’t vanity — abdominal fat has different metabolic implications than fat stored elsewhere, which is why it matters.

Hormonal fluctuations also affect your mood, your energy, your motivation, and your capacity for dealing with stress. If you’re feeling less resilient than you used to, that’s not weakness — it’s biochemistry. And understanding that is the first step towards adapting rather than fighting.

Why what worked in your 20s won’t work now

In your 20s, you could skip meals, do an intense gym session, eat a restrictive diet for a few weeks, and see results. Your metabolism was faster, your recovery was quicker, your hormones were stable, and your body was more forgiving of poor nutritional choices.

At 40+, all of that changes. And yet, so many women (and men) are still trying to use the same playbook:

  • Slash calories to 1,200-1,400
  • Do more cardio
  • Push through exhaustion
  • Ignore the stress and sleep deprivation
  • Wonder why nothing works anymore

The reason this approach fails at 40+ is that it adds more stress to a system that’s already under strain. Restrictive dieting further suppresses an already slowing metabolism. Excessive cardio increases cortisol when your cortisol is already elevated. Ignoring sleep and stress removes the very foundations that your body needs to regulate weight effectively.

The approach that works at this stage of life is fundamentally different. It’s gentler. It’s smarter. And it’s far more effective.

It’s never too late to feel strong in your body. Not thin. Not perfect. Strong.

The approach that works at this stage of life

Everything I’ve learned — as an athlete, as a coach, and as a woman navigating this phase myself — points to the same set of principles. They’re not exciting. They’re not trendy. But they work.

  1. Eat adequately. This is not the time for restriction. Your body needs proper fuel to manage hormonal changes, maintain muscle, support brain function, and regulate stress. Eat above your BMR, prioritise protein, include healthy fats, and stop fearing carbohydrates. I explore this in more detail in my post on losing weight without crash dieting.
  2. Build strength. Resistance training is non-negotiable at 40+. It preserves and builds muscle mass, supports bone density, boosts metabolic rate, and improves functional capacity. You don’t need a gym — bodyweight exercises, bands, and light weights at home are all effective.
  3. Prioritise recovery. Rest days are as important as training days. Your body’s recovery capacity has changed. Three well-structured sessions per week with adequate rest between them will produce better results than six exhausting ones.
  4. Address sleep seriously. This isn’t a nice-to-have. Sleep is when your body repairs, regulates hormones, and processes the day’s stresses. If your sleep is poor, work on that before worrying about anything else.
  5. Manage stress actively. Not passively, not by ignoring it. Actively. Daily walks, breathwork, time in nature, journalling, saying no to things that drain you — these aren’t optional extras. They’re essential components of a body that functions well.
  6. Be patient. Changes at 40+ take longer to show. Your body needs more time to adapt, to build muscle, to regulate itself. This is a long game — measured in months and years, not days and weeks.

Movement for strength, not punishment

If your exercise routine consists mainly of cardio — running, spinning, the cross-trainer — it’s time to rethink. I’m not saying stop doing what you enjoy. But at 40+, you need to make strength training the priority.

Here’s why: muscle is the engine of your metabolism. Every kilogram of muscle burns more energy at rest than fat does. As you age and naturally lose muscle, your metabolic rate drops. The only way to counter this is to actively build and maintain muscle through resistance training.

Strength training also supports bone density — critical for women as oestrogen declines — improves joint stability, enhances balance and coordination, and builds the kind of functional fitness that keeps you independent and capable as you age.

If you haven’t lifted weights before, or if it’s been years since you exercised regularly, that’s completely fine. I’ve written a whole guide on how to start exercising when it’s been a while. Start with what you can manage and build from there. The goal is consistency, not perfection.

Nourishment for energy, not deprivation

The women I coach in their 40s and beyond almost always share one thing in common: they’ve spent decades undereating. Years of diets have left their metabolisms adapted to low intake, their muscle mass reduced, and their relationship with food complicated by guilt and restriction.

At this stage of life, the priority is nourishment. That means:

  • Protein at every meal. Your body becomes less efficient at processing protein as you age, which means you need more of it to maintain muscle. Aim for a palm-sized portion at every meal — eggs, fish, lean meat, legumes, Greek yoghurt, nuts.
  • Healthy fats daily. Essential for hormone production, brain function, and satiety. Olive oil, avocado, nuts, seeds, oily fish.
  • Complex carbohydrates. Your brain and muscles need glucose. Whole grains, sweet potatoes, oats, fruits, and vegetables provide sustained energy.
  • Adequate fibre. Crucial for gut health, hormone metabolism, and satiety. Most women don’t eat enough. Vegetables, legumes, and whole grains are your best sources.
  • Plenty of water. Hydration affects everything from energy levels to skin quality to appetite regulation.

If you’ve been eating 1,200-1,400 calories for years, the idea of eating more might feel terrifying. But your body cannot function optimally on inadequate fuel. The path to better body composition at 40+ runs through nourishment, not deprivation.

It’s never too late to feel strong in your body

I want to end with this, because it’s the thing I feel most passionate about: your best years are not behind you.

I know the culture tells you otherwise. I know the magazines feature 25-year-olds and the fitness industry targets people in their 20s and 30s. But some of the most profound transformations I’ve witnessed have been in women in their 40s, 50s, and beyond.

Women who stopped running themselves ragged and started building strength. Women who stopped starving themselves and started eating properly. Women who stopped comparing themselves to who they were at 25 and started appreciating who they are now.

The goal isn’t to look 25 again. It’s to feel strong, energised, capable, and at home in the body you have right now. That’s achievable at any age — but it requires a different approach than the one that got you here.

You don’t need to turn back the clock. You need an approach that works with the body you have now — and honours everything it’s carried you through.

If you’re over 40 and feeling stuck, frustrated, or lost when it comes to your body, F.L.A.M.E was built for you. It’s a holistic programme that addresses nutrition, movement, mindset, and lifestyle — because at this stage of life, all four need to work together.

You’re not past your best. You’re just beginning a new chapter. And it can be a good one.