How to build and maintain muscle as a woman in your 20s, 30s, 40s, 50s, 60s and beyond

When you’re sweating through endless HIIT classes and seemingly getting nowhere, it’s easy to throw in the towel and accept that muscle loss is an inevitable part of the ageing process. But the latest scientific thinking^{1, 2} reveals that sarcopenia (the fancy term for age-related muscle loss) isn’t entirely unstoppable, and there are loads of strategic moves we can make to build lean muscle well into our 90s.

To help us understand exactly what’s going on with bodies through the decades - and how to boost muscle growth at any stage - we asked Dr Nicky Keay, a leading expert in endocrinology and author of the book ‘Hormones, Health and Human Potential’, to dish the facts.

You’ll often hear people complain that exercise feels tougher in their 30s, and while it might sound like a flimsy excuse to skip leg day, there’s actually some truth to it. Studies show that from age 30, you naturally lose about 3-8% of muscle mass per decade.⁷ “This loss, known as sarcopenia, can be subtle and may go unnoticed if you’re regularly hitting the gym,” notes Dr Keay.

By the time your 40s roll around, muscle mass loss can really ramp up, especially if climbing the corporate ladder, having kids or major responsibilities are standing in the way of your workouts.

“We know that levels of oestrogen, a hormone that protects muscle mass, begins to fluctuate and decline in women as they transition through perimenopause,” Dr Keay adds.

Without smart strategies to keep it in check, muscle loss picks up the pace from here on out, increasing to around 5-8% from your 60s and potentially more in your 70s and beyond.⁷

It’s no surprise, then, that as these hormones naturally decline with age, our muscles become less responsive to the demands we place on them. Unlike men, women face extra challenges in maintaining muscle as they age, because of perimenopause - the transitional phase leading to the end of menstruation, which usually begins in the mid-40s but can start as early as your 30s or as late as your 50s. “Oestrogen has a protective effect on muscle mass, supporting muscle protein synthesis and reducing inflammation,” says Dr Keay.¹⁰ “Because it naturally declines during this phase, we start to lose these benefits.” And with additional fun symptoms like insomnia, anxiety and mood swings thrown into the mix, perimenopause can seriously mess with your motivation to work out.

But beyond basic biology, lifestyle choices play a big role too. One 2004 research review linked a shortage of muscle-boosting protein sources and increased sedentary time - which are common with age - to changes in our muscle tissue.⁷

Cycle syncing means making the most of your hormone fluctuations throughout the month. From your period to ovulation, oestrogen and progesterone (typically) fall in a predictable pattern. So by timing your exercise to match these hormone shifts, you can max out the benefits in each phase. 

For example, studies have shown that stacking your weight training efforts in the follicular phase (the week after your period), when ‘go get-em’ oestrogen is riding high, can lead to a 15% increase in strength¹¹ (although Dr Keay caveats that not every woman will follow this pattern). After ovulation, progesterone levels rise, which can be great for pairing with fat burning endurance work.

Protein becomes a bigger priority in this decade too. “As we age, our bodies naturally produce fewer anabolic hormones that help build muscle,” she says. “By increasing your protein intake, you can help maintain muscle mass and support recovery and repair from workouts by providing the essential amino acids.” Try drinking a protein shake just before your workout, or swap crisps for protein-rich snacks like hard-boiled eggs, trail mi, or chopped veggies with chickpea-loaded hummus.

The key to effective strength training is progressive overload, so rather than lifting the same weights week in and out, focus on gradually increasing the reps and resistance in your training so you’re always making progress.

Resistance training, also called strength training, are exercises where you work against a force to build muscle strength and endurance. This force can come in many shapes and forms, like free weights, gym machines, resistance bands or even your own body weight. Scientifically speaking, resistance training works because it stimulates muscle fibres by creating tiny tears in the muscle tissue. As these tears repair, the muscles become stronger and more resilient.¹²

 “As you get older, you need more rest and recovery time because your hormone levels are lower, so they require more time and opportunity to drive those positive adaptations,” she notes. It’s easy to assume that your muscles grow stronger during the process of working out, but it’s actually during recovery when the real gains are made. While in rest, our anabolic hormones set to work, increasing the rate of protein synthesis, which helps to repair the microscopic tears in our muscles, ultimately making them stronger. 

 “​​Don't look at a rest day as being a lazy day,” she stresses. “If you try and train every single day, you’ll leave no time for the body to make the most of the hormones still available.” Not only can slow your gains, but it also puts you at higher risk of injury, especially as bones become more fragile with age.

“I would argue that resistance bands are actually better than free weights in some aspects, because they provide continuous resistance both when you contract the muscle and when you extend it, meaning the muscle is under tension throughout the entire movement,” Dr Keay reckons. “This continuous resistance helps to engage more muscle fibres and can lead to better muscle activation and strength.”

As a bonus, these cheap and cheerful gym bands are easy to slip on in front of the TV or to throw in your suitcase for a holiday workout. So if you’ve been struggling with minor aches, pains and twinges that have put you off pumping iron, don’t sweat it: a home YouTube workout with a rubber band can often be just as effective.

But as they say, knowledge is power. Exercising and resting in line with your age and what works for your body is key. Whether you’re 27 or 72... go get ‘em!