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Do muscles get bigger with age?

As we get older, our muscles naturally begin to change. Muscle mass and strength typically peak around age 30, and then start to slowly decline after that. However, with the right exercise routine, it is possible to maintain and even build muscle as you age. Here is a closer look at how muscles change with age and what you can do to keep yours strong.

Muscle Changes as You Age

Our muscles are made up of fibers that begin to change as we get older. Starting around age 30, we begin to lose muscle mass at a rate of 3-5% per decade. This gradual loss is referred to as sarcopenia, and results in smaller, weaker muscles over time. There are several factors that contribute to sarcopenia:

  • Loss of motor neurons: Signals from the nervous system to the muscles decline, resulting in loss of muscle fibers.
  • Lower hormones: Testosterone and growth hormones, which are important for building muscle mass, decrease with age.
  • Increased inflammation: Chronic inflammation can impair muscle building and repair.
  • Less physical activity: As activity levels decrease, muscles have less stimulation to stay strong.
  • Poor nutrition: Consuming adequate protein and calories is important to maintain muscle.

In addition to getting smaller, aging muscles also have fewer capillaries, mitochondria and nerves compared to younger muscles. This reduces their endurance capacity and ability to function properly.

Can You Still Build Muscle Mass as You Age?

The decline in muscle mass and strength that comes with aging is inevitable. However, the speed and degree to which you experience these changes is not set in stone. Remaining physically active can dramatically slow the rate of muscle loss associated with aging.

Not only that, but it is possible for older adults to continue building muscle mass well into their senior years through strength training and proper nutrition. Although the process may be slower than when you were younger, seniors can still achieve noticeable muscle growth.

Tips for Building Muscle as You Age

Here are some effective strategies to continue building muscle as you get older:

  • Focus on progressive overload – Slowly increase the amount of weight lifted over time to continually challenge your muscles.
  • Prioritize compound exercises – Squats, deadlifts and rows work multiple muscle groups at once.
  • Allow for adequate rest and recovery – Muscles need time to repair and strengthen between workouts.
  • Consume enough protein – Shoot for 25-30g of protein from high quality sources after workout sessions.
  • Manage stress – Chronic stress can raise cortisol and impair muscle growth.
  • Get enough sleep – Aim for 7-9 hours per night for optimal recovery.

While it may take longer to see results, many people over 50 and beyond can gain lean muscle mass through smart training and nutrition. Be patient, set realistic goals for yourself, and focus on progress over perfection.

Changes in Muscle Composition

In addition to a loss of overall muscle mass, aging causes a shift in the composition of our muscles. After age 50, the percentage of muscle tissue made up of Type I (slow twitch) muscle fibers increases, while the percentage of Type II (fast twitch) muscle fibers decreases. Some key differences between muscle fiber types:

Type I Type II
Slow contracting Fast contracting
Used for endurance Used for power/speed
Use oxygen for energy Use glucose for energy
Smaller in size Larger in size

This change in fiber type ratio means that older muscles are slower to develop force, but have greater endurance capabilities. They fatigue slower, but cannot produce as much power. This translates functionally into reduced strength, speed and muscle mass.

Loss of Fast Twitch Fibers

The loss of fast twitch muscle fibers has several causes as we age:

  • Reduced nerve input into fast twitch fibers, leading to atrophy.
  • Lower satellite cell count, reducing capacity to repair damage.
  • Shortened telomeres resulting in slowed cell division.
  • Altered hormone levels like growth hormone and testosterone.
  • Decrease in mitochondria and blood flow.

All of these factors contribute to preferential atrophy of Type II muscle fibers as we get older. However, researchers have found that staying physically active can help minimize the decline of fast twitch fibers.

Engaging in resistance training that targets fast twitch fibers can induce muscle hypertrophy and strengthen these powerful fibers even into old age. This will help maintain strength, mobility and balance.

Other Muscle Changes

In addition to overall loss of muscle tissue and shifts in fiber types, aging brings about other changes to our muscles, including:

  • More connective tissue and fat deposits between and around muscle fibers.
  • Reduced flexibility and range of motion.
  • Impaired blood flow and oxygen delivery to muscles.
  • Longer recovery time between exercise sessions.
  • Decreased coordination and slower nerve impulses.
  • Decline in insulin sensitivity.

These age-related changes contribute to the gradual loss of muscle performance. Staying active provides a potent defense against many of these changes.

Ways to Combat Muscle Loss

While some muscle loss is inevitable as you get older, there are steps you can take to slow this process and hold onto your strength:

Strength Training

Lifting weights several times per week is highly effective at reducing muscle loss associated with aging. Make sure to target all the major muscle groups and focus on progressively overloading the muscles.

Increase Protein Intake

Try to consume 0.5 – 1 gram of protein per pound of body weight daily from sources like meat, eggs, dairy and protein powder. Spread protein intake throughout the day.

Stay Active

Keep engaging in daily physical activity to stimulate the muscles. Take the stairs, go for walks, swim or cycle to preserve muscle mass.

Get Enough Sleep

Aim for 7-9 hours of quality sleep per night to allow muscles adequate time to recover and repair themselves.

Manage Stress

Chronic stress raises cortisol levels which can impair muscle growth. Practice stress management techniques like yoga, meditation or deep breathing.

Consume Nutrient Dense Foods

Focus your diet on lean proteins, fruits, vegetables, whole grains and healthy fats. Avoid processed foods high in sugar, sodium and unhealthy fats.

How Strength Training Builds Muscle as You Age

Research shows that a properly designed strength training program can boost muscle size and strength even in adults in their 70s and 80s. Here is how strength training stimulates muscle growth as you get older:

  • Progressively overloading the muscles forces them to adapt and grow.
  • Compound exercises like squats and deadlifts recruit fast twitch muscle fibers.
  • The mechanical tension triggers protein synthesis resulting in muscle hypertrophy.
  • Hormones like growth hormone and testosterone are increased.
  • Motor neuron activation is improved, stimulating muscle fibers.

For best results, focus on lifting heavier weights, allowing for adequate rest between workouts, and consuming protein after your session to supply muscles with amino acids for growth.


Some decline in muscle mass and strength is inevitable as we age. But through strength training, proper nutrition and an active lifestyle, it is possible to maintain and even build muscle past age 50. While the process of building muscle may be slower, seniors can still make significant strength and muscle gains.

Focus on exercises like squats, deadlifts and bench presses to target fast twitch muscle fibers most prone to atrophy. Have realistic expectations, train consistently, eat plenty of protein and make sure to allow muscles proper recovery time between workouts. With determination and perseverance, you can keep making fitness gains well into your senior years.