Why Lifting Weights Might Be The Most Important Thing You Do This Year
It addresses more of what's changing in your body after 40 than any other exercise
If you’re considering adding just one type of exercise to your routine this year, I’m hoping this post will convince you it needs to be resistance training.
For women 40+, resistance training gives you the highest return on investment in how you look, how you feel, how you function and how healthy you are.
The decline in female hormones in your 40s and later has far-reaching effects: easier weight gain, loss of muscle tissue and bone density, and changes in how your body manages blood sugar, maintains strength and keeps your brain sharp. Resistance training addresses all of these directly. And it doesn’t take much - research shows that two 20-minute sessions per week can change how your body functions for the next 30 years.
While resistance training refers to any exercise where your muscles work against a weight or force, whether that’s dumbbells, resistance bands, machines, or your own body weight, for the full benefits you want to be using resistance against increasingly heavier weights.
TL:DR: If you're only adding one type of exercise after 40, make it resistance training. It rebuilds the muscle you're losing (which manages blood sugar and burns calories), builds bone density, improves brain function and mood, reduces menopause symptoms, and changes how you look. Two 20-minute sessions weekly is enough to start seeing benefits. While cardio matters for heart health and fat loss, resistance training directly addresses more of what's changing in your body after 40.
Building Muscle: Your Primary Tool For Blood Sugar Control
Your skeletal muscles handle about 80% of glucose clearance from your bloodstream after you eat. When you eat a meal, glucose (a sugar from carbs used for fuel) enters your bloodstream and insulin get secreted and signals your muscles to pull most of it out and either use it for energy or store it.
When glucose stays elevated in your blood, it gets stored as fat. Efficient glucose clearance means less fat storage, better energy levels and lower risk of insulin resistance and type 2 diabetes.
From your 30s onwards, you lose about 3-5% of muscle mass every decade, which accelerates around menopause, because declining oestrogen reduces a type of cells that help regenerate muscle tissue by up to 60%. Some women lose 10% of their muscle mass after menopause, compared to early perimenopause.
Less muscle means fewer calories burned at rest. Not because your metabolism inherently slows - resting metabolic rate per kilogram of lean tissue stays the same from age 20 to 60. The issue is having less muscle tissue doing the burning. Muscle requires more energy to maintain than fat, so when you lose muscle and gain fat, your total daily calorie burn drops even if you’re eating and moving exactly the same.
Resistance training rebuilds and maintains muscle tissue and so regular resistance training can help you gain lean muscle mass even in your 50s, 60s and beyond.
What about aerobic activities? Walking and cycling are excellent for cardiovascular health but they don’t build significant muscle. Your body adapts to aerobic exercise by becoming more efficient at using oxygen, which is valuable for endurance and heart health - but it doesn’t build new muscle tissue.
Yoga and Pilates provide important strength benefits but you’re limited to your body weight or the limited resistance of Pilates equipment, and progressive load (increasing the weight you work against) is what triggers muscle growth.
When you challenge your muscles with resistance they can’t easily handle, you create tiny tears in the muscle fibres. Your body repairs these tears and builds the muscle back, slightly stronger and often larger, to handle that stress next time. This is why you need to keep increasing the weight - to keep triggering that adaptation.
Better Blood Sugar Control Independent Of Insulin
When your muscles contract during resistance exercise, they activate a glucose uptake system that works independently of insulin. This matters because insulin sensitivity typically declines with age, especially around menopause. When cells become less responsive to insulin, glucose stays elevated in your blood longer, leading to more fat storage and increased risk of type 2 diabetes.
Muscle contraction bypasses this problem entirely. When you lift weights, your muscles pull glucose out of your bloodstream without relying on insulin at all. This effect lasts up to 48 hours after a workout - your muscles continue clearing glucose more efficiently for two full days!
The result: better blood sugar control, reduced risk of type 2 diabetes, lower triglycerides and cholesterol, and less inflammation throughout your body.
If you’ve noticed energy crashes after meals, stubborn midlife weight gain that won’t shift with diet changes alone, or blood sugar numbers creeping up, resistance training directly addresses the mechanism causing these issues.
Aerobic exercise also improves insulin sensitivity and is particularly effective for fat loss, but resistance training builds the actual tissue that manages glucose long-term. The ideal approach is to do both, but for metabolic health, resistance training is the foundation.
You’ll Look Better And Your Clothes Will Fit Better
When women talk about wanting to look “toned,” they usually mean seeing muscle definition but not bulk. A toned look happens from both building muscle and reducing the body fat surrounding it. Resistance training does both.
As you build muscle and lose fat, your body composition changes even if the scale doesn’t move much. You might weigh the same but look completely different - smaller waist, more defined arms, back and legs. Your clothes will fit better. You will look leaner and more well, toned...
This isn’t about becoming bulky. Women don’t build large muscles easily, especially in the low-oestrogen environment after menopause. What happens instead is you develop visible muscle tone, your body becomes more compact, and you look stronger and healthier.
The physical changes are visible proof that your body is responding, which reinforces the habit and makes you want to continue.
Building Bone Density That Keeps You Independent
After menopause, women lose bone density at 1.5-2.5% per year for the first decade. There are some scary statistics to know: half of all women over 50 will break a bone due to osteoporosis (weak, brittle bones). A hip fracture after 75 isn’t just about the broken bone - it’s about the cascade of immobility, muscle loss and loss of independence that comes with it.
Your bones are living tissue that respond to stimulus. When you load them with weight, you trigger a process called mechanotransduction. The mechanical load suppresses a protein that acts as a brake on bone formation. When you lift weights, you release the brake, and your bones start building density again.
Research shows women who did high-intensity resistance training twice a week for eight months gained nearly 3% bone density in their lumbar spine while women who didn’t exercise lost over 1%. The resistance training group also gained density in their hip bones, increased cortical bone thickness by almost 14%, and gained an average of 2mm in height as their spines strengthened (i read that part of the research 3 times to convince myself it’s true… yes, they gained height).
Walking or swimming doesn’t produce this effect. They don’t load your bones enough to trigger significant bone building, since you need actual weight bearing down on the skeleton.
Building bone density in your 40s and 50s is an important investment in staying mobile and independent at 75 and beyond.
Sharper Thinking And Better Memory
When your muscles contract, they release molecules into your bloodstream that travel to your brain and trigger production of brain-derived neurotrophic factor, or BDNF. BDNF supports brain cell survival, promotes new neural connections and helps clear protein plaques associated with Alzheimer’s disease.
In research, women who did resistance training twice a week showed improved executive function (planning, focus and problem-solving) and better verbal memory. Brain scans showed reduced shrinking of the brain’s white matter compared to women who didn’t do resistance training. These effects were seen for a full year after training stopped.
Resistance training also increases insulin-like growth factor 1 (IGF-1), which supports brain cell communication and survival.
Your brain doesn’t have to decline as you age. What you do now in your 40s and 50s to keep it sharp pays off for decades - and resistance training is one of the tools that helps.
Better Mood And Less Anxiety
Resistance training has been shown to produce substantial reductions in depressive symptoms and significant reductions in anxiety, especially at low to moderate intensity.
So much so, that the effect is comparable to aerobic exercise and some medications. The benefit were seen regardless of whether an individual gains strength - the act of training itself triggers it.
Resistance training increased serotonin (the neurotransmitter that helps regulate mood) and endorphin (responsible for the post-exercise high) release, reduced inflammatory markers throughout the body (inflammation is increasingly linked to depression), and helped normalise stress hormone response (the body becomes better at managing cortisol spikes and returns to baseline faster).
There’s also a psychological component - you feel stronger, more powerful and more capable as you see yourself improving.
In research, women who did resistance training three times a week for several months saw significant reductions in both depression and anxiety symptoms that lasted for months after training stopped.
You don’t need heavy weights - even light to moderate intensity creates a positive effect.
Fewer Hot Flushes And Better Sleep During Menopause
In research, women who did resistance training three times a week for 15 weeks reduced their hot flushes intensity nearly in half. A larger reduction than what’s typically seen with aerobic exercise.
Resistance training seems to be enhancing the body’s natural system that controls temperature regulation, which helps stabilise the thermoregulatory system that becomes erratic during hot flushes.
Resistance training also improves sleep quality and overall quality of life during menopause. Some initial research even suggests it might help maintain oestrogen levels slightly.
This isn’t a universal fix - research results vary. But there’s evidence that resistance training can help, which makes it worth including in your toolkit.
Stronger Joints And Less Pain
Resistance training, done with appropriate progression (gradually increasing weight), reduces sports injuries to less than a third of baseline rates and cuts overuse injuries nearly in half. For every 10% increase in resistance training volume, injury risk drops by more than 4 percentage points.
Like your muscles, your tendons and connective tissue need loading to stay strong. A single resistance training session doubles the rate of collagen synthesis in your tendons. After several months of consistent training, tendons become stiffer in a functional sense - they transfer force more efficiently and become more resistant to injury.
For chronic lower back pain, resistance training that strengthens the relevant muscles, has been shown to significantly reduce pain intensity and improve quality of life - addressing the cause rather than just managing symptoms.
Strength exercise can also prevent and alleviate frozen shoulder pain, which affects mostly women (75% more than men) and peaks between ages 40-60, again - during perimenapause and meanapause.
How Resistance Training Supports Your Gut Health
There appears to be bidirectional communication between your muscles and your gut bacteria. Women who build strength through resistance training show specific changes in their gut microbiome, particularly increases in bacteria that produce short-chain fatty acids. These fatty acids are anti-inflammatory and support gut barrier function.
Resistance training also reduces markers of intestinal permeability and increases the protective mucus layer in the intestinal lining, supporting overall gut health.
The gut microbiome affects protein metabolism, insulin sensitivity and inflammation - all factors that matter for muscle and general health. Working your muscles appears to send signals back to the gut that influence bacterial composition.
Just two sessions a week can make a difference
You don’t need hours in the gym. Research shows that two sessions per week of 20 minutes each can produce significant, sustained health benefits. In the first several months, even once per week creates meaningful results.
A session consists of eight to ten exercises covering major muscle groups, starting with one set of each and total beginners can see significant gains with even a single set per exercise.
The equipment doesn’t matter much when starting. Bodyweight exercises, resistance bands, dumbbells, machines or barbells all work. What matters is challenging your muscles enough that the last few repetitions feel difficult (Bone density benefits specifically require actual weight-bearing load, not just working against resistance.)
Why Start Here
Aerobic exercise is important for cardiovascular health, lung capacity, mood and fat loss. Don’t stop walking, cycling or swimming.
But if you’re only adding one thing, or need to prioritise because time is limited, resistance training addresses more of what changes in women’s bodies after 40:
Builds and maintains muscle (aerobic exercise doesn’t)
Builds bone density (aerobic exercise provides minimal benefit)
Creates the metabolic machinery for long-term glucose management
Provides specific cognitive benefits for executive function
Directly addresses the muscle loss and metabolic changes that accelerate during menopause
The ideal scenario includes both and my favourite combination is daily walking and strength training. But for the collection of changes that happen after 40, resistance training addresses more of them at their source.
You’ll be stronger. You’ll move better. Your body composition will improve so you will love the way you look in the mirror. Your risk of fractures, diabetes, cognitive decline and depression will all decrease. You’re building a body that will be there for you at 60, 70 and 80.
No less important, you wil feel powerful and capable. It’s incredible how seeing yourself improving and becoming stronger affects feeling capable in other areas.
All you need to do is start.
Your body will handle the rest.