You might have noticed that keeping up your strength feels a little harder in your 40s than it did a decade ago — and there's a good reason for that. From around the age of 30, adults begin to gradually lose muscle mass, and this process tends to accelerate after 40. Research suggests that with the right habits, a great deal of this loss may be slowed or even partially reversed at any age.
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\n- Age-related muscle loss, known as sarcopenia, typically begins in your 30s and may speed up after 40 — but it is not inevitable.
\n- Resistance training is consistently identified in research as one of the most effective tools for preserving and building muscle mass as you age.
\n- Getting enough protein — and spreading it across meals — is associated with better muscle maintenance in older adults.
\n- Sleep, stress management, and staying active day-to-day all play a supporting role in healthy muscle ageing.
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What Is Sarcopenia and Why Does It Happen?
\n\nSarcopenia is the medical term for the gradual loss of muscle mass, strength, and function that tends to accompany ageing. Research suggests adults may lose somewhere between 3% and 8% of their muscle mass per decade after 30, with the rate potentially increasing after 60. While some degree of change is a natural part of ageing, sarcopenia at its more severe end is associated with reduced mobility, increased risk of falls, and lower quality of life.
\n\nSeveral factors contribute to this process. Hormonal changes — including declining levels of testosterone and oestrogen — play a role, as does reduced physical activity, lower protein intake, and changes in how efficiently the body uses protein to build and repair muscle tissue. Inflammation, which tends to increase with age, may also be a contributing factor, though this is an active area of research.
\n\nIt's worth emphasising that sarcopenia is not simply an unavoidable consequence of getting older. Many of the contributing factors are modifiable, which means the choices you make now can genuinely make a difference to how your muscles hold up over time.
\n\nThe Role of Resistance Training
\n\nIf there is one strategy that appears consistently across the research on muscle loss and ageing, it is resistance training — also called strength training or weight training. Multiple studies suggest that progressive resistance exercise is one of the most effective interventions for preserving and even rebuilding muscle tissue in adults over 40, including those well into their 60s, 70s, and beyond.
\n\nResistance training works by creating small amounts of stress in the muscle fibres, which then adapt and rebuild slightly stronger. This process — called muscle protein synthesis — remains possible throughout life, though it may require a little more stimulus as you age. Research indicates that older adults may need to train at a relatively high effort level (using weights that feel genuinely challenging) to see meaningful results, compared to younger adults.
\n\nYou don't need a gym to get started. Bodyweight exercises such as squats, lunges, press-ups, and resistance band work can all be effective, especially for beginners. If you're new to strength training or returning after a break, our guide to strength training at home with no equipment is a good place to start. As you progress, gradually increasing the challenge — through added weight, more repetitions, or reduced rest time — is key to continuing to make gains. This principle is known as progressive overload.
On a related note, see this piece on strength training after 40: build muscle safely.
This pairs well with this piece on how much protein do you need after 50? a guide.
You might enjoy our article about flexibility training for older adults: safe s as a follow-up.
\n\nMost exercise guidelines suggest aiming for at least two resistance training sessions per week, targeting all major muscle groups. As always, please speak to your GP or a qualified fitness professional before starting a new exercise programme, particularly if you have any existing health conditions or joint concerns.
\n\nProtein: How Much, and When?
\n\nAlongside exercise, dietary protein is one of the most well-studied areas in muscle preservation research. Protein provides the amino acid building blocks that muscles need to repair and grow. The challenge is that older adults appear to be less efficient at using dietary protein for muscle building — a phenomenon sometimes called anabolic resistance — which means protein needs may be higher in midlife and beyond than they were in younger years.
\n\nCurrent research suggests that adults over 40 may benefit from consuming more than the general recommended daily allowance of protein, with many sports nutrition and ageing researchers suggesting figures of around 1.2–1.6 grams of protein per kilogram of body weight per day. However, the evidence is still evolving and individual needs vary considerably. Consulting a registered dietitian is the best way to understand what's right for you personally.
\n\nTiming and distribution also appear to matter. Some studies indicate that spreading protein intake across three or more meals — rather than consuming most of it in one sitting — may be more effective for stimulating muscle protein synthesis throughout the day. Practical sources of quality protein include eggs, fish, poultry, dairy products, legumes, tofu, and meat. For a broader look at how macronutrients work together, see our guide to understanding macronutrients.
\n\nSleep, Recovery, and Hormonal Health
\n\nMuscle isn't actually built during exercise — it's built during recovery, and sleep is when a significant portion of that recovery happens. During deep sleep, the body releases growth hormone, which plays an important role in muscle repair and maintenance. Consistently poor sleep quality is associated with reduced muscle recovery and, over time, may contribute to muscle loss.
\n\nResearch also suggests that sleep deprivation can affect levels of cortisol (a stress hormone) and reduce insulin sensitivity — both of which may negatively impact muscle tissue over time. Getting seven to nine hours of quality sleep per night is widely recommended for adults, and many people find that improving their sleep habits has benefits that extend well beyond how rested they feel. You might find our article on building a bedtime routine to improve sleep quality a useful starting point.
\n\nFor women, the hormonal changes of perimenopause and menopause can affect muscle mass and strength. Declining oestrogen levels are associated with accelerated muscle loss in some women, which makes the strategies discussed in this article particularly relevant during this life stage. Our overview of exercise for managing menopause symptoms covers this in more detail.
\n\nThe Importance of Staying Generally Active
\n\nWhile structured resistance training sessions are important, research also highlights the value of overall daily movement — sometimes called non-exercise physical activity. Spending long periods sitting, even if you exercise regularly, is associated with poorer metabolic and musculoskeletal health. Simple habits like walking more, taking the stairs, or breaking up long periods of sitting with light movement all contribute to a healthier picture overall.
\n\nWalking, in particular, is a low-impact activity that most people can incorporate regardless of fitness level. Some studies suggest that regular walking may help preserve lower body strength and functional mobility as we age, especially when combined with structured strength work. If you're looking to build a sustainable walking habit, our guide to starting a walking fitness plan offers a practical, step-by-step approach.
\n\nBalance and mobility work are also worth including in your routine — not only to support muscle function, but also to reduce the risk of falls, which becomes increasingly important as we age. Activities like yoga, tai chi, and targeted balance exercises are often recommended alongside strength training for older adults.
\n\nNutrition Beyond Protein: Supporting Muscle Health Holistically
\n\nWhile protein often takes centre stage in discussions about muscle mass, other nutrients also play a supporting role. Vitamin D, for example, is associated with muscle function and strength, and deficiency is relatively common — particularly in people who spend limited time outdoors. Some studies suggest that adequate vitamin D levels may be linked to better muscle performance in older adults, though the evidence for supplementation as a direct intervention is mixed.
\n\nCreatine is another supplement that has attracted considerable research attention in the context of ageing. Some studies suggest it may support muscle strength and function in older adults when combined with resistance training, though it is not a replacement for exercise or a balanced diet. If you're considering any supplementation, it's worth discussing this with your GP or a registered dietitian first.
\n\nOverall dietary quality matters too. Diets rich in vegetables, fruit, wholegrains, healthy fats, and varied protein sources are broadly associated with better health outcomes across the board, including markers related to muscle and bone health. Rather than focusing on single nutrients in isolation, a whole-diet approach tends to be what the evidence most consistently supports.
\n\nPractical Tips: How to Get Started
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- Begin with two resistance training sessions per week. Target all major muscle groups — legs, back, chest, shoulders, and core. Bodyweight exercises are a perfectly valid starting point. \n
- Gradually increase the challenge over time. As exercises start to feel easier, add more resistance, reps, or sets. This progressive overload is what drives continued adaptation. \n
- Include protein at every meal. Aim for a meaningful source of protein at breakfast, lunch, and dinner rather than saving most of it for one meal. Eggs, Greek yoghurt, fish, legumes, and lean meat are all good options. \n
- Prioritise sleep. Aim for seven to nine hours per night. Good sleep hygiene — consistent bedtimes, a cool dark room, limiting screens before bed — can make a real difference to sleep quality. \n
- Move more throughout the day. Set reminders to stand up and move if you have a desk job. Even short walks between tasks can contribute to your overall activity levels. \n
- Consider your vitamin D status. Talk to your GP about whether testing or supplementation might be appropriate for you, particularly if you have limited sun exposure. \n
- Track your progress. Keeping a simple log of your workouts and how they feel can help you spot progress and stay motivated. Use our calorie calculator or BMI calculator as part of a broader picture of your health goals. \n
- Consult your GP before making significant changes. This is especially important if you have existing health conditions, joint problems, or haven't been active for a while. \n
Key Takeaways
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- Age-related muscle loss (sarcopenia) is common but not inevitable — lifestyle choices can meaningfully influence how much muscle you preserve as you age. \n
- Resistance training at least twice a week is consistently supported by research as one of the most effective ways to maintain and build muscle mass after 40. \n
- Adequate protein intake — likely higher than the general population recommendation — and spreading it across meals may support better muscle maintenance. \n
- Quality sleep and general daily activity both contribute to the muscle health picture and should not be overlooked. \n
- A holistic approach combining exercise, nutrition, sleep, and stress management is likely to be more effective than focusing on any single factor alone. \n
This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider before making changes to your health routine.