How Does Muscle Change With Age—and Can Strength Training Slow It Down?
Most people think of muscle as something that affects appearance or athletic performance. In reality, muscle is one of the body’s most important long-term health assets.
Your muscles help you climb stairs, carry groceries, maintain balance, protect your joints and recover from illness. They also play an important role in blood glucose regulation and metabolic health.
As we get older, however, muscle mass, strength and power can gradually decline. This process is often called age-related muscle loss. In more advanced cases, it may contribute to sarcopenia—a condition involving low muscle strength, reduced muscle quantity or quality, and poorer physical performance.
The good news is that muscle ageing is not entirely outside our control. Regular resistance training, adequate daily movement and appropriate nutrition can substantially influence how well our muscles function later in life.
When Does Muscle Loss Begin?
There is no single age at which everyone suddenly starts losing muscle.
Muscle development is generally strongest during early adulthood. From midlife onwards, changes may begin gradually and can easily go unnoticed. A person’s body weight may remain similar even while muscle decreases and body fat increases.
Several changes may occur with age:
Muscle fibres can become smaller.
Fast-twitch fibres involved in power and quick reactions may be particularly affected.
More fat may accumulate within and around muscle tissue.
The nervous system may become less efficient at recruiting muscle.
Muscles may respond less strongly to food and exercise.
Illness, injury and inactivity may become more frequent.
The speed of decline varies considerably. Training history, daily activity, health conditions, nutrition, sleep and periods of illness can all affect an individual’s future muscle health.
Strength Can Decline Faster Than Muscle Size
One of the most important findings from ageing research is that muscle strength may decline considerably faster than muscle mass.
The Health, Aging and Body Composition Study followed 1,880 older adults over three years. Leg lean mass decreased by approximately 1% per year, while leg strength declined by around 2.6% to 4.1% per year across different groups.
In other words, strength declined approximately three times faster than muscle mass.
This suggests that healthy ageing is not simply about preserving the size of a muscle. Muscle quality, nervous-system function, coordination and the ability to generate force are also important.
It also explains why body weight alone tells us very little. Someone can maintain a stable weight while losing strength and gradually finding activities such as standing up, climbing stairs or carrying objects more difficult.
Why Inactivity Becomes More Serious With Age
Muscle needs a reason to remain strong. When it is no longer challenged, the body gradually reduces the amount of muscle tissue and capacity it maintains.
For a younger adult, a quiet week may have little noticeable effect. For an older adult, extended inactivity caused by illness, injury, hospitalisation or prolonged bed rest can have a much greater impact.
In one small controlled study, researchers reduced the daily steps of 10 healthy older adults, with an average age of 72, by approximately 76%. Participants completed about 1,400 steps per day for two weeks.
After only 14 days, the researchers observed:
An approximately 3.9% reduction in leg fat-free mass
A roughly 26% reduction in the muscle protein-building response after eating
Reduced insulin sensitivity
Unfavourable changes in inflammatory markers
Because this study included only 10 people and measured leg fat-free mass rather than pure muscle tissue alone, the exact percentage should not be applied to everyone. However, it demonstrates how quickly reduced movement can affect older muscle.
What May Happen to Different Types of People?
Research cannot predict exactly what will happen to an individual. However, it can help us understand the likely direction associated with different lifestyles.
People Who Perform Regular Strength Training
People who consistently train against resistance generally build a larger reserve of muscle and strength.
They will still experience biological ageing, but they may begin from a higher level and maintain the physical capacity required for daily life for longer. Progressive training can also support bone health, joint stability, balance and confidence with movement.
The goal is not to prevent every age-related change. It is to delay the point at which those changes begin to limit independence.
People Who Mainly Perform Cardio
Walking, running, cycling and swimming offer important benefits for cardiovascular fitness, metabolic health and endurance.
However, aerobic fitness and muscular strength are not the same thing. A person may be able to walk or cycle for a long time while still lacking upper-body strength, grip strength or the ability to produce high levels of force.
A healthy ageing program should therefore include both aerobic activity and resistance training.
Occasional Exercisers
Occasional activity is better than no activity, but inconsistent training may not provide enough progressive stimulus to maintain strength over many years.
Walking once or twice when time allows, for example, is positive—but it may not adequately challenge all the major muscle groups. Consistency matters more than completing an extremely difficult workout every few weeks.
Sedentary Office Workers
Office work does not automatically lead to muscle loss. The concern is the combination of prolonged sitting, low daily step counts and no structured strength training.
During early adulthood, this lifestyle may not appear to cause any obvious problems. Over time, however, reduced muscle stimulus may contribute to declining strength, increasing body fat and poorer metabolic health.
A workout cannot make continuous sitting irrelevant, either. Office workers benefit from combining structured exercise with regular walking, standing and movement throughout the day.
People Who Do Not Exercise
People who remain inactive may have less physical reserve available when they encounter illness, surgery or injury.
This can create a cycle:
Less activity → loss of strength → everyday movement feels harder → even less activity
Breaking this cycle becomes more difficult once basic tasks are already challenging. Building strength earlier is generally easier than trying to recover it after a major period of inactivity.
Do Lifelong Athletes Still Lose Muscle?
Yes—but their starting point and rate of functional decline may be different.
A study comparing younger and older competitive male athletes with non-athletic controls found that older strength, sprint and endurance athletes had more favourable body-composition measures than age-matched non-athletes.
However, exercise did not completely eliminate the effects of ageing.
A more recent MRI study examined the hip and leg muscles of younger athletes, older Masters athletes and non-athletic controls. The combined muscle volume of the gluteal, quadriceps and calf muscles averaged approximately:
5,285 mL in older Masters athletes
4,379 mL in older non-athletic controls
The older athletes also had less muscular fat infiltration than the older control group. Nevertheless, both groups of older adults produced substantially less peak power per unit of muscle than the younger participants.
The message is realistic but encouraging: lifelong exercise does not stop ageing, but it can meaningfully change the amount of strength and muscle a person carries into later life.
Is It Ever Too Late to Start Strength Training?
For most people, it is not too late to benefit from an appropriately designed program.
In one study, adults aged 65–75 and adults over 85 completed 12 weeks of whole-body resistance training three times per week.
Following the program:
Quadriceps cross-sectional area increased by approximately 10% in the 65–75 group.
Quadriceps area increased by approximately 11% in the group aged over 85.
Whole-body lean mass increased by approximately 2% in both groups.
Leg-extension strength improved by approximately 38% and 46%, respectively.
The training responses were not significantly different between the two age groups.
This does not mean every 85-year-old should begin with heavy gym training. Exercise needs to match the individual’s health, mobility and experience. However, the study demonstrates that very old muscles can still adapt to resistance training.
What Should You Train for Healthier Ageing?
An effective healthy-ageing program should train more than one muscle or one exercise. It should prepare the body for the demands of everyday life.
1. Lower-Body Strength
Lower-body strength supports walking, stair climbing, getting out of a chair and recovering your balance.
Useful movement patterns include:
Squats or chair stands
Split squats or supported lunges
Step-ups
Hip-hinge or deadlift variations
Calf raises
Beginners can start with body weight, a stable chair or light resistance before gradually progressing.
2. Glutes and Posterior-Chain Muscles
The glutes, hamstrings and back muscles contribute to posture, hip stability, lifting ability and efficient walking.
These muscles can be trained with:
Hip bridges
Romanian deadlift variations
Cable or resistance-band pull-throughs
Rows
Controlled back-extension movements
3. Pushing, Pulling and Grip Strength
Upper-body strength helps with carrying groceries, opening doors, lifting household objects and supporting the body during a loss of balance.
A balanced program may include:
Push-ups or chest presses
Rows or lat pulldowns
Overhead presses
Loaded carries
Appropriate grip exercises
4. Power
Strength describes how much force you can produce. Power describes how quickly you can produce it.
Power becomes especially important when you need to react quickly—for example, taking a fast step after losing your balance.
People with an appropriate training base may benefit from controlled movements performed with a faster lifting phase. Power training should be introduced carefully, particularly for beginners or people with medical or musculoskeletal conditions.
5. Balance
Balance training becomes increasingly important with age.
Simple exercises may include:
Supported single-leg stands
Heel-to-toe walking
Controlled step-ups
Direction changes
Reaching tasks from a stable position
Balance exercises should be performed in a safe environment with appropriate support available.
How Much Exercise Do Adults Need?
The World Health Organization recommends that adults complete:
150–300 minutes of moderate-intensity aerobic activity each week, or
75–150 minutes of vigorous-intensity aerobic activity, or an equivalent combination
Muscle-strengthening activities involving all major muscle groups on two or more days per week
Older adults should also include activities that emphasise functional balance and strength on three or more days per week when possible.
Importantly, some activity is better than none. Beginners do not need to reach the full recommendation immediately.
A Practical Weekly Starting Point
For a generally healthy adult, a realistic week might include:
Two or three full-body strength sessions
Regular walking or another enjoyable aerobic activity
Short movement breaks during the working day
Balance exercises two or three times per week
Adequate food, protein and sleep to support recovery
Strength sessions should gradually become more challenging. Progress may come from adding a small amount of weight, completing more repetitions, improving the range of motion or performing a more demanding variation.
The program does not need to be extreme. It needs to be safe, consistent and progressive.
If you are looking for guidance with strength training in Hurstville, the Wellness Department team can help you find a training approach that suits your current experience, ability and goals.
The Takeaway
Ageing is unavoidable, but severe physical decline is not determined by age alone.
Muscle mass, strength and power may all decrease over time, with strength often declining faster than muscle size. Long periods of inactivity can accelerate the process, especially in older adults.
Regular resistance training cannot keep the body permanently young. What it can do is build a greater physical reserve, slow the loss of function and help you remain capable for longer.
The best reason to train is not simply to lift more today. It is to preserve your ability to stand, walk, carry, climb and live independently in the decades ahead.
Frequently Asked Questions
At what age do you start losing muscle?
There is no universal starting age. Gradual changes can begin during midlife, but the rate varies according to activity, health, nutrition and training history. Decline often becomes more noticeable later in life or following illness and inactivity.
Is walking enough to prevent age-related muscle loss?
Walking is excellent for general activity and cardiovascular health, but it may not provide enough resistance to maintain strength across all major muscle groups. Combining walking with at least two weekly strength sessions is a more complete approach.
Can people over 70 build muscle?
Yes. Research shows that adults in their 70s, 80s and beyond can improve muscle size and strength through appropriately programmed resistance training.
How often should I perform strength training?
The WHO recommends muscle-strengthening activity involving all major muscle groups on at least two days per week. Beginners should start at a manageable level and progress gradually.
Do I need heavy weights?
Not necessarily. Body-weight exercises, resistance bands, machines and free weights can all be effective when the exercise is sufficiently challenging and progresses over time. The safest option depends on the individual.
Can cardio replace strength training?
No. Cardio and strength training produce overlapping but different benefits. A well-rounded program should include both.
Evidence Summary
Longitudinal research indicates that muscle strength may decline around three times faster than leg lean mass in older adults.
Short periods of sharply reduced activity can negatively affect leg lean tissue, insulin sensitivity and muscle protein synthesis.
Older lifelong athletes generally retain more muscle and less muscular fat than inactive people of a similar age, although exercise does not completely stop ageing.
Resistance training can improve muscle size, strength and physical performance in adults over 85.
Both aerobic exercise and muscle-strengthening activity should be included in a healthy-ageing program.
These findings describe group averages and cannot precisely predict an individual’s future health.
Scientific Sources & References
Goodpaster, B.H., Park, S.W., Harris, T.B., et al. (2006). “The loss of skeletal muscle strength, mass, and quality in older adults: The Health, Aging and Body Composition Study.” The Journals of Gerontology: Series A, 61(10), 1059–1064.Supports the finding that strength declined substantially faster than leg lean mass in older adults.PubMed | DOI
Breen, L., Stokes, K.A., Churchward-Venne, T.A., et al. (2013). “Two weeks of reduced activity decreases leg lean mass and induces anabolic resistance of myofibrillar protein synthesis in healthy elderly.” The Journal of Clinical Endocrinology & Metabolism, 98(6), 2604–2612.Supports the discussion of reduced daily steps, leg fat-free mass and the muscle protein-synthesis response in older adults.PubMed | DOI
Nunes, E.A., Montiel-Rojas, D., Nilsson, A., et al. (2023). “Body composition in male lifelong trained strength, sprint and endurance athletes and healthy age-matched controls.” Frontiers in Physiology, 14.Supports the comparison between lifelong athletes and age-matched non-athletic adults.PubMed
Leg and hip muscles show muscle-specific effects of ageing and sport on muscle volume and fat fraction in male Masters athletes. (2025). The Journal of Physiology.Provides MRI evidence comparing muscle volume and fat fraction in younger athletes, older Masters athletes and non-athletic controls.PubMed
Muscle Mass and Strength Gains Following Resistance Exercise Training in Older Adults 65–75 Years and Older Adults Above 85 Years. (2024). The Journals of Gerontology: Series A.Supports the conclusion that adults over 85 can increase quadriceps size, lean mass and strength following 12 weeks of resistance training.PubMed
Tsuzuku, S., Kajioka, T., Sakakibara, H., & Shimaoka, K. (2018). “Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.” Scandinavian Journal of Medicine & Science in Sports, 28(4), 1339–1344.Supports the use of accessible body-weight resistance training for improving muscle thickness and strength in older adults.PubMed | DOI
World Health Organization. (2020). WHO Guidelines on Physical Activity and Sedentary Behaviour.Provides the recommendations for weekly aerobic activity, muscle-strengthening exercise and balance-focused activity.WHO publication | Detailed recommendations
Health Disclaimer
This article provides general health and fitness information only. It is not a substitute for individual medical advice, diagnosis or treatment. People with cardiovascular conditions, osteoporosis, significant joint problems, balance difficulties, recent surgery or other health concerns should consult an appropriate healthcare professional before beginning a new exercise program.
Comments