Uncovering the everyday muscle-related triggers behind declining strength and mobility

Muscle weakness isn’t just about ageing—it’s often the outcome of preventable factors that quietly chip away at our physical strength and activities. In India, where nutritional gaps, sedentary lifestyles, and late diagnoses are common, recognising the top causes of muscle weakness is the first step toward protecting long-term mobility and health.

This blog explores five of the most frequent, causes of muscle weakness based on findings from research. The goal is simple: help patients and doctors alike identify risks early, intervene meaningfully, and build lasting strength with everyday actions.

1. Protein Deficiency: A Common but Overlooked Culprit

India has one of the highest prevalence rates of dietary protein deficiency. Despite rising awareness, many people consume significantly less protein than global recommendations. Inadequate intake directly impacts muscle protein synthesis, leading to reduced repair, poor muscle tone, and chronic fatigue. Moreover, in some people specific proteins/ amino acids for structural muscle and protein formation is lacking.

Studies suggest Indian diets tend to be cereal-heavy and low in high-quality protein/amino acids especially in vegetarian households¹. Muscle tissue depends on adequate/specific amino acids to maintain mass, rebuild after exertion, and support endurance. Additionally in some cases specific proteins are needed to prevent muscle breakdown.

How to spot it?

• Feeling tired despite adequate sleep
• Slow recovery from workouts or daily chores
• Reduced grip strength
• Inability to walk stairs
• Muscle pain
• Inability to stand from a seated position

Solution: Prioritise protein-rich foods (dal, eggs, milk, paneer, soy, fish) in every major meal. Adults may need up to 1.2–1.5 g/kg of body weight per day, especially after 40.

2. Vitamin D Deficiency: Weak Muscles Start Here

Vitamin D is critical for calcium absorption, which also is crucial for muscle contraction, balance, and coordination. Deficiency is rampant due to limited sun exposure, higher skin coverage, pollution, and poor dietary sources².

Even mild deficiency has been linked to poor muscle action leading to

• Increased risk of falls and fractures (especially in the elderly)
• Poor muscle tone and power
• Slower healing after injury

How to spot it?

• Generalised fatigue and weakness
• Aches in muscles, sometimes with joint or bone pain
• Repeated cramps or spasms

Solution: Get your 25(OH)D levels checked. Safe sun exposure and supplements (as prescribed) can restore muscle efficiency over time.

3. Age-Related Muscle Loss (Sarcopenia)

From the age of 30, muscle mass begins to decline—slowly at first, then more rapidly after 50. This process, called sarcopenia, is driven by age-related hormonal shifts, inactivity, inflammation, and reduced protein synthesis³. Sometimes this is aggravated due to other associated diseases in the individual.

Sarcopenia often goes unnoticed until:

• Balance becomes unstable
• Recovery from illness or surgery is prolonged
• There’s unexplained weight loss and fatigue

How to spot it?

• Trouble rising from chairs
• Decline in walking speed
• Increased dependence on support for everyday tasks
• Decline in ability to continue any activity (endurance)

Solution: Resistance exercises (bodyweight, weights, yoga), spread protein intake across the day, specific nutritional formulations, and limiting/ stopping medications that may impact strength.

4. Inactivity and Sedentary Lifestyle

The modern adult—especially in urban areas—spends more than 9 hours seated daily, often without meaningful physical activity. Prolonged inactivity leads to disuse atrophy: a shrinking of muscle fibres due to lack of engagement or activities ⁴.

Muscles are highly adaptable. When unused, they shrink, degenerate or break down. When engaged regularly—even at low intensity—they regain tone and function.

How to spot it:

• Getting tired quickly after light exertion
• Feeling stiff after long periods of rest
• Slouching posture or poor core control

Solution: Stand every hour, include stretching, take stairs, and commit to at least 30 minutes of movement daily.

5. Chronic Conditions That Affect Muscle Function

Several chronic conditions can impair muscle performance by affecting metabolism, nerve conduction, protein turnover, or overall systemic health:

• Diabetes: High blood sugar levels can lead blocked entry of glucose into muscles This leads to lack of energy to sustain muscle function. Over time, this reduces muscle responsiveness and increases fatigue.

• Thyroid Disorders: Both hypothyroidism and hyperthyroidism disrupt metabolic rate and protein synthesis. Hypothyroidism, in particular, can cause muscle stiffness, cramps, and weakness due to slowed cellular processes for energy metabolism.

• Chronic Kidney Disease (CKD): CKD often results in uremia, electrolyte imbalances, and reduced appetite—all of which contribute to muscle protein loss and overall fatigue. It’s also linked to metabolic acidosis, which accelerates muscle breakdown.

• Neurological Conditions: Diseases such as stroke, paralepsis, Parkinson’s disease quite commonly affect nerve-muscle coordination, leading to progressive weakness, spasms, or difficulty in movement disuse and inability to perform daily activities.

• Progressive weakness in limbs

• Asymmetrical strength loss

• Associated symptoms (e.g., numbness, hormonal changes, swelling)

• Inability to perform activities of daily living

How to spot it?

Solution: Early diagnosis, regular monitoring, and tailored interventions (like physiotherapy or neuromuscular support) based on the primary condition specific diet can improve symptoms and prevent further muscle loss.

Strengthening the Foundation for Healthy Movement

Muscle weakness is not an inevitable part of ageing—it’s often a signal that something needs correcting. Whether it’s diet, movement, or underlying health issues, timely intervention can restore function, reduce fatigue, and improve quality of life.

For those over 40, prioritising muscle health is as essential as heart or bone health. With awareness and small, consistent steps, we can prevent loss before it impacts independence.

References

1. An Analysis of Protein Consumption in India Through Plant and Animal Sources
2. Vitamin D and your health: Breaking old rules, raising new hopes
3. Cruz-Jentoft, A.J., et al. "Sarcopenia: European Consensus on Definition and Diagnosis." Age and Ageing, 2019
4. Cleveland Clinic. "Muscle Atrophy”
5. Mayo Clinic - Muscular Dystrophy: Symptoms and Causes

Frequently Asked Questions (FAQ)

1. What is the most common cause of muscle weakness in adults?

Protein deficiency is among the top contributors, especially due to cereal-based diets that lack adequate amino acids. Low protein intake impacts muscle recovery, strength, and endurance. In urban areas, sedentary lifestyles and low Vitamin D further compound this.

2. Can muscle weakness be reversed?

In many cases, yes. When caught early, muscle weakness due to nutritional or lifestyle causes can be reversed with proper exercise, diet, and medical advice. For age-related or disease-related weakness, interventions can still slow decline and improve function.

3. How can I know if I’m losing muscle mass?

Early signs include feeling more tired after activity, reduced ability to lift or carry things, needing support while climbing stairs, and noticing physical changes like thinner limbs or loose skin. A DEXA scan can also assess muscle mass loss. Some people gain weight due to higher fat mass. They to have certain muscle loss.

4. Do women experience muscle loss differently than men?

Yes. Postmenopausal women experience a sharper decline in muscle mass due to reduced oestrogen. This, combined with lower baseline strength, makes early muscle care essential. Muscle-focused nutrition and resistance training are highly effective. Women with PCOS gain weight, and this weight gain is due to fat deposits, which always occurs with net muscle mass loss.

5. When should I consult a doctor about muscle weakness?

If weakness is sudden, worsening, affects one side of the body, or is associated with pain, fatigue, or mobility issues, consult a physician or orthopeadician. It may indicate sarcopenia, neurological issues, or underlying conditions. Even in case of younger people loss of weight may indicate loss of muscle. In older individuals, presence of symptoms of a chronic disease needs doctor consultation.