Maintaining muscle strength in men as you age

Discover how men's muscles change with age, why strength matters and the training, nutrition and recovery habits that help maintain it.

Skeletal muscle is the body's largest organ by mass, and it shapes far more than how you look or lift. It stores and uses energy, supports the joints, and helps the body stay steady and mobile through the decades. For men, muscle tends to follow a predictable arc across a lifetime, building through early adulthood and gradually declining from midlife.

This article looks at how men's muscle changes with age, why strength matters for long term health and independence, and the everyday habits that help support muscle function over time, from training and nutrition through to recovery and key nutrients.

Why muscle strength matters beyond fitness and appearance

Muscle is active tissue that does metabolic work every day. A review in Comprehensive Physiology describes skeletal muscle as the largest organ in the body by mass and the site of roughly 80% of glucose uptake from the blood after a meal. That gives muscle a central place in how the body manages blood sugar and energy.

Strength also shapes everyday life. The muscles that help you stand up, climb stairs, carry shopping and keep your balance all depend on being maintained over time. Keeping strength as the years pass helps men stay active, mobile and independent, and supports the steady energy that makes daily tasks feel easier. For men, the value of muscle strength shows up in how well the body moves and functions across the years, rather than in how it looks.

How men's muscle mass changes with age

Muscle mass is not fixed. It responds to how much you use it, what you eat, your hormones and your age. Men typically reach peak muscle mass in early adulthood and hold it through their thirties before a slow decline sets in.

The Frontiers in Nutrition review notes that people begin to lose muscle mass from around 40 years of age, with the pace of loss tending to pick up in later decades. Strength can fade even faster than size. A quantitative review in Frontiers in Physiology reported that ageing muscles lose strength several times faster than they lose mass, and that low strength is a more consistent predictor of disability than low muscle mass alone.

Both size and strength matter, and strength often deserves the closer attention. This is a large part of why men lose functional capacity with age even when the change on the scales looks modest.

The connection between muscle strength, joints and mobility

Muscles and joints work as a team. Strong muscles around a joint help absorb load and keep the joint stable through everyday movements like standing, climbing stairs and lifting. When the muscles supporting a joint are stronger, that joint has more support during those movements.

Mobility depends on this partnership. The Australian 24-Hour Movement Guidelines recommend that adults include functional activities targeting mobility, balance and coordination on three or more days a week, alongside strength work. Keeping muscle strong is one way to support the balance and coordination that help men stay steady and active as they age.

Strength training basics for long term men's health

Resistance training is the most direct way to support muscle. It signals the body to maintain and build muscle tissue, and it works at any age.

The Australian 24-Hour Movement Guidelines recommend that adults aged 18 to 64 do muscle strengthening activities at least two days a week, working the major muscle groups. This can look like:

• Bodyweight moves such as squats, push ups and lunges
• Free weights or resistance machines
• Resistance bands
• Loaded everyday tasks like carrying shopping or digging in the garden

You do not need a gym or heavy loads to start. Beginning with a manageable resistance and adding a little over time lets the body adapt safely, a principle known as progressive overload. Two well planned sessions a week, kept up consistently, tend to do more for maintaining strength after 40 than the occasional hard effort. If you are returning to exercise after a long break or have a health condition, a check in with your GP or an exercise physiologist is a sensible first step.

Protein, nutrition and hydration for muscle maintenance

Food gives muscle the raw materials to repair and rebuild. Protein leads here, because it supplies the amino acids that muscle is made from.

Older adults may need more protein than the standard adult guideline to help maintain muscle. A 2024 review in Frontiers in Nutrition advised a protein intake of around 1.0 to 1.2 grams per kilogram of body weight a day for muscle and bone health in older adults, above the general adult reference intake of about 0.8 grams per kilogram. The same review noted that protein does most for muscle when paired with resistance training, rather than on its own.

Spreading protein across meals helps, since the body uses it more steadily that way. Good sources include lean meat, fish, eggs, dairy, legumes, tofu, nuts and seeds. A varied plate also supplies the other nutrients muscle relies on, from a wide mix of vegetables, fruit and wholegrains.

Hydration plays a role too. Muscle tissue holds a large share of the body's water, and staying well hydrated supports normal muscle function during activity. Water is the simplest choice for most people throughout the day.

The role of magnesium in normal muscle function

Magnesium is one of the nutrients muscle depends on. According to the NIH Office of Dietary Supplements, magnesium acts as a helper in hundreds of reactions in the body, including those that release energy and those that allow muscles to contract and relax. It also plays a part in the nerve signals that tell muscles when to fire.

Many Australians fall short on magnesium from food alone. According to the Australian Bureau of Statistics 2023 Usual Nutrient Intakes release, around 31% of Australians did not meet their magnesium requirements from food and drinks alone. The recommended dietary intake set by the NHMRC is 420 mg a day for men aged 31 and over (400 mg for men in their twenties) and 320 mg a day for women. Good food sources include green leafy vegetables, legumes, nuts, seeds and wholegrains.

Where a supplement may fit

When dietary intake is inadequate, a magnesium supplement can help top up daily intake. Blackmores Magnesium Glycinate provides magnesium in a glycinate form that is well absorbed and gentle on the stomach, delivering 150 mg of magnesium per tablet. Magnesium contributes to normal muscle function and helps maintain the body's electrolyte balance, and the formula supports muscle health and healthy sleeping patterns when dietary intake is inadequate. If you are weighing up which option suits your routine, our guide to choosing a Blackmores magnesium walks through the differences across the range.

Why sleep and recovery matter for maintaining strength

Muscle adapts and repairs during rest, not during the workout itself. Sleep is a large part of that recovery window.

Short sleep appears to work against muscle maintenance. A study in Physiological Reports found that a single night of total sleep deprivation reduced the rate of muscle protein building by 18% the following day, alongside a rise in the body's main stress hormone. Over time, consistently short sleep can make it harder for the body to hold onto muscle.

The Australian 24-Hour Movement Guidelines recommend that adults aim for seven to nine hours of good quality sleep with consistent bed and wake times. Rest days between hard training sessions also give muscle the time it needs to adapt.

Practical habits to support muscle health after 40

Supporting muscle after 40 comes down to a handful of habits repeated consistently:

• Do muscle strengthening activity at least twice a week, working the major muscle groups
• Include protein at each meal from a mix of sources
• Eat a wide variety of vegetables, fruit, wholegrains, legumes and nuts
• Stay hydrated across the day
• Aim for seven to nine hours of sleep most nights
• Keep moving in general, with walking, stairs and daily activity
• Where diet falls short, consider whether a supplement has a place in filling the gap

None of these needs to be dramatic. Small, steady choices, kept up over months and years, are what support muscle and strength through midlife and beyond.

Key takeaways

Muscle is the body's largest organ and sits at the centre of movement, metabolism and independence. Men reach peak muscle in early adulthood, with a slow decline beginning from around 40 and strength often fading faster than size.

Resistance training on at least two days a week is the strongest lever for muscle maintenance, supported by adequate protein, a varied diet, good hydration and quality sleep. Magnesium and other nutrients contribute to normal muscle function, and a supplement can help when dietary intake falls short.

Maintaining muscle is a long game built from consistent daily habits. Starting where you are, and keeping at it, is what counts.

Always read the label and follow the directions for use.

Disclaimer: This article provides general information only and is not intended to diagnose, treat, cure, or prevent any disease. The information presented is not a substitute for professional medical advice. If you have concerns about your health, please consult your GP or healthcare provider for a personalised assessment and recommendations. Supplements should not replace a balanced diet.