Why Muscle Health Matters for Metabolic Health and what we can do about it

When we think about metabolic health, we often focus on body weight, blood glucose, cholesterol, blood pressure and body fat. But there is another important piece of the metabolic picture that we sometimes overlook - our muscles.

Skeletal muscle is not simply the tissue that enables us to walk, lift, climb stairs and carry shopping. It is also a major metabolic organ. Muscle stores glucose as glycogen, uses large amounts of glucose and fatty acids for energy, responds to insulin and communicates with other tissues through a range of signalling molecules.

This means that maintaining healthy muscle throughout life is important not only for strength and mobility, but also for maintaining healthy blood glucose, insulin sensitivity, body composition and metabolic health, and of which are critical for general health.

Muscle mass and strength may decline with age. However, the good news is that we can take action to strengthen and maintain our muscles with physical activity, nutrition and other lifestyle changes, which we describe below. So lets all take action to do this!

Why is muscle matters for metabolic health?

After a meal, carbohydrates are broken down into glucose and released into the bloodstream. Insulin helps direct glucose into tissues, particularly skeletal muscle, where it can be used for energy or stored as glycogen.

In fact, skeletal muscle is the major site of glucose disposal after a meal and during physical activity, and healthy muscle helps blood glucose levels reduce quicker after eating.

A 2025 review in Physiological Reviews describes muscle as the main site of glucose deposition and a major consumer of glucose during exercise. Muscle contraction can stimulate glucose uptake through pathways that are partly independent of insulin.

This is important because insulin resistance in skeletal muscle is one component of whole-body insulin resistance.

When muscle becomes less responsive to insulin, glucose may remain in the circulation for longer and the pancreas may need to produce more insulin to maintain normal blood glucose levels, a condition known as insulin resistance. Over time insulin resistance can increase the risk of type 2 diabetes and other cardiometabolic health issues. This is why muscle health matters for metabolic health.

Exercise provides a particularly useful stimulus because contracting muscles can increase glucose uptake even when insulin signalling is impaired.

Muscle is also a metabolic reservoir

Muscle acts as a large storage site for amino acids and glycogen. It also contributes to energy expenditure and helps determine how the body handles nutrients.

Maintaining muscle is therefore particularly important during periods of weight loss. Losing body weight is not necessarily the same as losing body fat: some of the weight lost during dieting can come from lean tissue, including muscle.

This is one reason that preserving muscle should be considered alongside losing excess body fat when improving metabolic health.

A 2025 review examining muscle health in people with type 2 diabetes highlights the close relationship between muscle loss, insulin resistance, obesity and metabolic dysfunction.

Muscle health isn't just about muscle size

When we talk about muscle health, this does not mean it is necessary to have visibly large muscles - it doesn't!

Four related aspects of muscle health are important:

• Muscle mass – how much muscle tissue you have

• Muscle strength – how much force you can produce

• Muscle quality – how effectively the muscle functions relative to its size

• Physical function – what you can actually do with your muscles, such as walking, climbing stairs, getting up from a chair or carrying shopping

As we age, muscle mass and strength tend to decline. More substantial age-related loss of muscle and function is known as sarcopenia.

Importantly, muscle decline isn't simply an inevitable consequence of getting older. Physical inactivity, insufficient protein and energy intake, illness and other factors can accelerate it, while resistance exercise and adequate nutrition can help counteract it.

Strength training supports metabolic health

If you want to maintain healthy muscle, resistance exercise is fundamental.

Resistance exercise includes anything that makes muscles work against resistance, such as:

• lifting weights

• using resistance bands

• bodyweight exercises

• squats and sit-to-stands

• lunges

• press-ups

• rowing movements

• carrying weights

• using resistance machines.

You don't have to become a bodybuilder. The aim is to give the muscles a sufficiently challenging stimulus to maintain or increase their strength and capacity.

The UK's Chief Medical Officers recommend muscle-strengthening activities involving all the major muscle groups on at least two days per week. They also recommend at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous activity each week for adults.

Why resistance exercise helps metabolism

Resistance exercise can:

• stimulate muscle protein synthesis

• preserve or increase muscle mass

• improve muscle strength

• improve glucose uptake

• improve insulin sensitivity

• increase the capacity of muscle to store glycogen

• help maintain physical function

• support healthy body composition.

Resistance exercise can improve metabolic health even in those with type 2 diabetes. A 2025 meta-analysis of 43 randomised controlled trials involving more than 2,000 middle-aged and older adults with type 2 diabetes found that resistance training improved measures including HOMA-IR,(a measure of insulin resistance), fasting glucose and HbA1c, while also increasing muscle mass and strength.

Another 2025 systematic review and meta-analysis specifically examining resistance training in people with type 2 diabetes and overweight or obesity also found resistance exercise also led to improvements in several cardiometabolic outcomes.

You don't need to train every day

Muscles need both stimulus and recovery. For many people, two or three resistance-training sessions per week can provide an excellent foundation. Beginners can start with relatively light resistance and gradually increase the challenge.

The key principle is progressive overload - as an exercise becomes easier, gradually increase the resistance, repetitions, range of movement or difficulty.

If you are new to strength training, recovering from illness or have a medical condition, start at an appropriate level and seek professional advice.

Don't forget to keep moving!

A common mistake is to think that a workout compensates for spending the rest of the day sitting.

It is increasingly clear that muscle benefits from being used regularly throughout the day. Walking, climbing stairs, gardening, housework and simply getting up from a chair all involve muscle contraction.

This may also have an immediate metabolic effect. A 2026 systematic review and meta-analysis of randomised trials found that breaking up prolonged sitting reduced post-meal glucose and insulin responses in healthy adults.

Another 2026 meta-analysis found that short activity breaks, particularly walking, reduced post-meal glucose and insulin responses compared with prolonged sitting.

So rather than thinking solely in terms of “exercise”, it may be helpful to think about movement throughout the day plus structured exercise. Small amounts of movement can add up.

Protein - the building material for muscle

Exercise provides the stimulus for muscle adaptation, but muscles also need adequate nutrition.

Protein provides the amino acids required to build and repair muscle proteins.

Good sources of protein include:

• fish

• eggs

• yoghurt and other dairy foods

• milk

• lean meat and poultry

• tofu and tempeh

• beans and lentils

• soya foods

• nuts and seeds

• protein powders may also be helpful

Protein requirements are individual and depend on factors including age, body size, activity, energy intake and health status.

The standard adult protein reference intake in the UK is approximately 0.75 g/kg body weight/day, but this is not necessarily an optimal target for maintaining muscle in older or for highly active people.

Research and expert groups now suggest higher protein intakes for older adults and for those who are physically active. The PROT-AGE recommendations, for example, suggest approximately 1.0–1.2 g/kg/day for healthy adults over 65, with at least 1.2 g/kg/day often suggested for those who are physically active.

Spread protein across the day

It is best to spread your protein intake across the three meals of the day reasonably equally rather than consuming most of your daily protein at dinner.

For example:

Breakfast: eggs, plus Greek yoghurt with nuts and seeds,

Lunch: lentil salad with feta or tofu

Dinner: fish, chicken or meat with vegetables

Snack: yoghurt, cottage cheese or another protein-rich food

The emphasis should be on adequate total protein within an overall nutritious diet, rather than becoming preoccupied with precisely timing every gram.

A 2024 systematic review found that combining protein supplementation with resistance exercise improved muscle mass and strength in older adults with sarcopenia.

Choose a nutrient-dense diet for muscle health

Muscle health requires more than protein. Muscle tissue needs energy, vitamins, minerals, essential fatty acids and other nutrients to function properly.

Prioritise adequate protein, sufficient energy and a nutrient-dense diet. Foods such as vegetables, fruit, legumes, whole grains, nuts, seeds, dairy or fortified alternatives, fish, meat or other protein sources can all contribute useful nutrients, but there is no single food group that is indispensable for muscle health.

• Vegetables and fruit to provide fibre, potassium, magnesium, folate, vitamin C and a wide range of plant compounds.

• Protein-rich foods – to supply amino acids for muscle protein synthesis.

• Nuts and seeds - provide protein, minerals and unsaturated fats.

• Fish and seafood - provide protein and, in oily fish, the long-chain omega-3 fatty acids EPA and DHA.

• Dairy or fortified alternatives - can provide protein, calcium and other nutrients important for musculoskeletal health.

• Healthy fats - include foods such as extra-virgin olive oil, nuts, seeds and oily fish.

There isn't one ideal dietary pattern for muscle health. Mediterranean-style, vegetarian, pescatarian and other balanced dietary patterns can all provide the necessary nutrients if properly planned.

 

What about carbohydrates?

Carbohydrates provide glucose that can be stored as muscle glycogen and used as fuel during exercise. They can be particularly useful for people undertaking frequent, prolonged or high-intensity exercise. However, carbohydrate is not essential for maintaining muscle mass, and there is no strong evidence that higher carbohydrate intake independently increases muscle growth when protein and energy intake are adequate.

Don't severely restrict calories for long periods

Very-low-calorie diets and aggressive weight-loss programmes can make it more difficult to maintain muscle. When energy intake falls substantially, the body draws on stored energy, and some lean tissue can be lost alongside fat.

This doesn't mean that weight loss should be avoided when someone has excess body fat. Rather, the goal should be to lose excess fat while preserving as much muscle and strength as possible.

Resistance training and adequate protein are particularly important during weight loss.

This is becoming especially relevant as medications and other interventions that produce substantial weight loss become more widely used. Maintaining muscle during weight loss is an increasingly important area of research.

 

Vitamin D, calcium and other nutrients

Several nutrients are important for normal muscle and musculoskeletal function.

Vitamin D

Vitamin D contributes to normal muscle function as well as bone health.

Exposure to sunlight in the summer helps us to make Vitamin D, however during the Winter months most people need to take a vitamin D supplement to avoid deficiency.

Calcium

Calcium is essential for normal muscle contraction as well as maintaining bone. Good dietary sources include dairy foods, tofu, canned fish containing bones, sesame seeds and certain leafy vegetables.

Magnesium

Magnesium contributes to normal muscle and nervous-system function. Sources include nuts, seeds, whole grains, legumes and green vegetables.

What about creatine?

Creatine is one of the better-researched supplements for increasing exercise capacity and muscle strength, particularly when combined with resistance training.

It may be particularly useful for some older adults because the ability to maintain muscle and strength becomes increasingly important with age.

However supplementation should not replace resistance exercise and adequate nutrition.

Recent research shows an additional benefit of combining creatine with resistance training, particularly for strength.

People with kidney disease or other relevant medical conditions should discuss creatine supplementation with an appropriate healthcare professional before taking it.

Sleep matters too

Muscle isn't built during excercise itself. Exercise provides the stimulus; recovery allows the body to adapt.

Sleep is therefore another important part of maintaining metabolic and muscle health.

Poor or insufficient sleep is associated with impaired insulin sensitivity and adverse cardiometabolic effects. A 2024 review described several potential pathways linking inadequate sleep with impaired insulin sensitivity, including effects on appetite regulation, circadian rhythms, physical activity and metabolism.

It is best to aim for a consistent sleep pattern and sufficient sleep for your individual needs.

Good sleep routines include:

• keeping a regular bedtime and waking time

• getting daylight exposure during the day, especially first thing in the morning

• keeping the bedroom dark and not too hot

• limiting stimulating activities close to bedtime

• avoiding excessive alcohol

• addressing persistent sleep problems rather than simply accepting them as inevitable.

Stress and metabolic health

Chronic stress can also influence metabolic health through effects on sleep, appetite, physical activity, food choices and hormonal regulation.

Stress itself isn't necessarily harmful—it is a normal physiological response—but persistent stress combined with inadequate recovery can make healthy lifestyle behaviours more difficult to maintain.

Activities such as walking outdoors, spending time with other people, relaxation practices, hobbies and mindfulness may therefore have indirect benefits by helping support sleep, movement and healthy eating.

Muscle health as we get older

Muscle health becomes particularly important as we get older. Loss of muscle strength can affect everyday independence - e.g getting out of a chair, climbing stairs, carrying shopping, getting up from the floor or maintaining balance.

Muscle loss is not inevitable and it is possible to take action to preserve muscle as we get older.

A combination of resistance exercise, adequate protein, sufficient micronutrients, regular movement and good sleep provides a strong foundation for maintaining muscle function.

Research also suggests that the combination of exercise and nutrition can be particularly useful. A 2024 systematic review and meta-analysis found improvements in muscle mass and strength when protein supplementation was combined with resistance exercise in older adults with sarcopenia.

In summary

1. Strength train 2–3 times a week

Work the major muscle groups – legs, hips, back, chest, shoulders, arms and abdomen. Start at a manageable level and progressively increase the challenge.

2. Move every day

Walking is an excellent starting point - look for opportunities to walk, climb stairs, garden, cycle or perform other activities you enjoy ona daily basis.

3. Break up sitting

Avoid spending several consecutive hours sitting without moving.

Even short activity breaks can improve post-meal glucose and insulin responses.

4. Eat enough protein

Include a protein-rich food at each main meal. As people get older, paying particular attention to adequate protein becomes increasingly important.

5. Eat a nutrient-dense diet

Prioritise vegetables, fruit, legumes, whole or minimally processed foods, protein-rich foods such as fish, meat, dairy, eggs, soya, nuts, seeds and healthy fats.

6. Don't rely solely on the scales

Weight is only one measure of health, consider strength, fitness, waist circumference, body composition and physical function as well.

7. Prioritise sleep and recovery

Allow your body time to recover from exercise and aim for consistent, good-quality sleep.

8. Avoid unnecessary muscle loss during weight loss

If losing weight, combine sensible calorie restriction with adequate protein and resistance exercise rather than relying on severe dietary restriction alone.

Final thoughts - we can do it!

Muscle is a metabolic organ that matters throughout adulthood, and the health of our muscles is important for all of us. Healthy muscle helps us use glucose, store glycogen, respond to insulin, remain physically active and metabolically healthy.

A decline in muscle health is not inevitable and it is within our gift to take action to keep our muscles healthy. Keeping active, using resistance exercise, enjoying a good diet with sufficient protein and adopting good sleep routines, will all combine to help preserve one of the body's most important metabolic tissues throughout life. We can all do this!

Key references

• Richter EA, Bilan PJ, Klip A. A comprehensive view of muscle glucose uptake: regulation by insulin, contractile activity, and exercise. Physiological Reviews. 2025;105:1867–1945. (PubMed)

• Wang J, Fan S, Wang J. Resistance training enhances metabolic and muscular health and reduces systemic inflammation in middle-aged and older adults with type 2 diabetes: a meta-analysis. Diabetes Research and Clinical Practice. 2025;229:112941. (PubMed)

• Al-Mhanna SB et al. Impact of resistance training on cardiometabolic health-related indices in patients with type 2 diabetes and overweight/obesity: a systematic review and meta-analysis of randomised controlled trials. British Journal of Sports Medicine. 2025;59:733–746. (British Journal of Sports Medicine)

• Whaikid P, Piaseu N. The effectiveness of protein supplementation combined with resistance exercise programs among community-dwelling older adults with sarcopenia: a systematic review and meta-analysis. Epidemiology and Health. 2024;46:e2024030. (PubMed)

• The effect of dose, frequency, and timing of protein supplementation on muscle mass in older adults: a systematic review and meta-analysis. Ageing Research Reviews. 2024;99:102325. (ScienceDirect)

• Gale JT et al. The Acute Effects of Interrupting Prolonged Sitting With Regular Activity Breaks on Postprandial Glucose and Insulin in Adults: A Systematic Review and Meta-Analysis. Obesity Reviews. 2026. (PubMed)

• Duraccio KM et al. Sleep extension and cardiometabolic health: what it is, possible mechanisms and real-world applications. The Journal of Physiology. 2024;602:6571–6586. (The Physiological Society)

• UK Chief Medical Officers. UK Chief Medical Officers' Physical Activity Guidelines. (GOV.UK)