Mitochondrial Health: How Your Cells Make and Lose Energy

Mitochondrial health is how well the mitochondria inside your cells turn food and oxygen into usable energy, and how well the body keeps those mitochondria in good repair. Healthy mitochondria support energy, recovery and healthy ageing. Their function tends to decline with age and inactivity, and regular movement remains the best-evidenced way to support them.

Mitochondria are often called the powerhouses of the cell, but that label undersells them. They also help control how cells signal, adapt to stress and decide when to repair themselves or be replaced. Understanding how they make energy, and why they lose it, explains a great deal about fatigue, metabolism and ageing in 2026’s longevity conversation.

What are mitochondria?

Mitochondria are small structures inside most human cells that produce the majority of the cell’s energy in the form of a molecule called ATP (adenosine triphosphate). A single cell can contain anywhere from a few to several thousand mitochondria, depending on how much energy that tissue needs.

Energy-hungry tissues such as heart muscle, skeletal muscle, the brain and the liver are rich in mitochondria. Mature red blood cells, by contrast, have none at all. Mitochondria also carry their own small set of DNA, called mitochondrial DNA, which is inherited from the mother and holds 37 genes that are essential for energy production.

How do your cells make energy?

Your cells make energy by breaking down glucose and fatty acids from food and passing the released electrons along a chain of proteins in the inner membrane of the mitochondria. This process, called oxidative phosphorylation, uses oxygen and produces most of the body’s ATP. Every heartbeat, thought and muscle movement depends on it.

The process runs in three broad stages:

• Breakdown of fuel. Glucose is first split in the cell’s fluid, and fatty acids are broken down inside the mitochondria, producing carriers loaded with electrons.
• The citric acid cycle. Inside the mitochondria, these fuels are processed further, releasing carbon dioxide and generating more electron carriers.
• The electron transport chain. Electrons pass along a series of protein complexes, which pump hydrogen ions across the inner membrane. The flow of those ions back across the membrane drives the enzyme ATP synthase, which makes ATP.

The body does not store much ATP. It recycles it constantly, and over a day the total amount turned over is estimated to be roughly equivalent to a person’s own body weight. That constant demand is why mitochondrial efficiency matters so much.

Why do mitochondria lose energy with age?

Mitochondria lose energy with age because damage accumulates faster than the cell can clear and replace worn-out mitochondria. Mitochondrial DNA picks up mutations, energy output falls, and the systems that recycle damaged mitochondria slow down. Researchers list mitochondrial dysfunction as one of the twelve recognised hallmarks of ageing.

Several processes are involved, and they reinforce one another:

• Declining quality control. Mitochondria constantly fuse and divide, and damaged ones are removed by mitophagy, a selective form of the cell’s recycling process. Our article on autophagy and cellular recycling explains this clearance system in detail. When it slows, faulty mitochondria persist.
• Oxidative stress. Energy production naturally creates reactive oxygen species. In small amounts these act as useful signals. When mitochondria are damaged, they produce more, which can harm mitochondrial DNA and proteins.
• Falling NAD+ levels. NAD+ is a molecule the mitochondria need to process fuel. Studies show its levels tend to decline with age in several tissues.
• Inactivity. Muscle mitochondria respond to use. Long periods of sitting and low activity are linked to lower mitochondrial content and capacity.

Mitochondrial decline is closely tied to other hallmarks, including chronic inflammation and loss of cellular repair capacity. The wider picture is set out in our guide to the 12 hallmarks of ageing.

What are the signs of poor mitochondrial health?

There is no single symptom or simple home test that confirms poor mitochondrial health in an otherwise healthy person. Reduced exercise tolerance, slow recovery and persistent low energy can reflect declining mitochondrial function, but each of these has many other possible causes, from anaemia and thyroid problems to poor sleep and depression.

It helps to separate two very different situations:

If tiredness is new, severe or worsening, a medical assessment comes first. Lifestyle support for mitochondria works alongside proper diagnosis, not in place of it.

How can you improve mitochondrial health naturally?

You can support mitochondrial health naturally through regular physical activity, steady sleep, a balanced diet that avoids constant overeating, and managing long-term stress. Exercise has the strongest evidence: it signals cells to build new mitochondria, a process called mitochondrial biogenesis, and to clear out damaged ones.

Move regularly, and include some intensity

Endurance exercise and interval training both increase mitochondrial content in muscle, largely through a signalling pathway involving the proteins AMPK and PGC-1α. In a 2017 Mayo Clinic study published in Cell Metabolism, 12 weeks of high-intensity interval training increased mitochondrial capacity by 49% in adults aged 18 to 30 and by 69% in adults aged 65 to 80. Older muscle, in other words, still responds strongly to training. Strength training adds benefits for muscle mass and metabolic health.

Protect your sleep

Sleep is when much of the body’s repair work happens, and short or irregular sleep is linked to poorer metabolic health. A consistent sleep and wake time, a dark room and limited late-night screen use are simple foundations. Our article on the clinical science of sleep optimisation covers how deep sleep supports repair in the brain.

Eat for metabolic balance

Mitochondria cope poorly with a constant surplus of fuel. Persistently high blood sugar and excess body fat are associated with mitochondrial strain, particularly in muscle and liver, and are closely linked to insulin resistance and its early signs. A diet built on vegetables, legumes, whole grains, nuts, seeds and adequate protein, with fewer ultra-processed foods, supports steadier metabolism. Time-restricted eating shows promise for mitochondrial health in animal studies, but human evidence is still limited.

Manage long-term stress

Short bursts of stress can help mitochondria adapt, but chronic stress keeps the body in a prolonged state of high demand. Breathwork, meditation, time in nature and restorative yoga help the nervous system return to a calmer baseline, which supports overall recovery.

Be cautious with supplements

NAD+ precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) reliably raise NAD+ levels in human trials, but clear improvements in mitochondrial function or health outcomes have not yet been consistently shown. Other popular supplements, including CoQ10, have mixed evidence outside specific medical conditions. Any supplement is best discussed with a doctor, especially alongside regular medication.

What does Ayurveda say about cellular energy?

Ayurveda does not describe mitochondria, but it does describe agni, the digestive and metabolic fire believed to transform food into nourishment at every level of the body, including the tissues. In Ayurvedic thinking, weak or irregular agni leads to the build-up of ama, or metabolic residue, which is seen as a root of fatigue and imbalance.

Some practitioners draw a loose parallel between agni at the tissue level and cellular metabolism. This is a conceptual comparison, not a scientific equivalence, but the practical advice overlaps: regular meals, appropriate activity, good sleep and timely purification. Ayurveda’s dedicated branch of rejuvenation builds on these foundations, as explained in our guide to Rasayana therapy.

How does Swastik support mitochondrial health?

Swastik Wellbeing Sanctuary in Khadakwasla, Pune supports mitochondrial health through its Cellular Vitality and Longevity programme, which integrates Ayurveda, Naturopathy, Yoga Therapy, Physiotherapy and contemporary mitochondrial and regenerative methods. The programme focuses on cellular energy pathways, metabolic regulation, reducing oxidative load and supporting tissue renewal.

Swastik describes itself as India’s first regenerative wellbeing sanctuary integrating ancient healing traditions with modern science to restore the body’s natural capacity to heal, regenerate, and thrive. Within that approach, regenerative wellbeing is the practice of supporting the body’s own systems of repair and renewal, rather than only managing symptoms. Mitochondria sit at the centre of that idea, which is explored further in our pillar article, What Is Regenerative Wellbeing?

Programmes begin with a wellness assessment that includes Ayurvedic pulse diagnosis (Nadi Pariksha) and a constitution (prakriti) evaluation, which guide a personalised plan of diet, movement, therapies and rest. Because cellular renewal is gradual, a minimum stay of 7 to 14 days is recommended, with the habits continued at home afterwards.

Frequently Asked Questions

What is the main function of mitochondria?

The main function of mitochondria is to produce ATP, the molecule cells use for energy, by breaking down glucose and fatty acids with oxygen. Mitochondria also help regulate cell signalling, calcium balance, heat production and programmed cell death, which is why their health affects so many systems in the body at once.

Can you increase the number of mitochondria in your cells?

Yes. Regular exercise, especially endurance and interval training, signals muscle cells to build new mitochondria through a process called mitochondrial biogenesis. Studies show this response continues in older adults. Consistency matters more than intensity alone, so a sustainable routine of walking, cycling, swimming or interval sessions, combined with strength work, is the most reliable approach.

Does mitochondrial function really decline with age?

On average, yes. Research shows that mitochondrial energy output tends to fall with age, mitochondrial DNA accumulates damage, and the clearance of faulty mitochondria slows. Much of this decline is linked to inactivity rather than age alone, which is why physically active older adults often show better mitochondrial function than sedentary younger people.

Which foods are good for mitochondrial health?

No single food fixes mitochondria, but an overall balanced diet helps. Vegetables, fruits, legumes, whole grains, nuts, seeds and sufficient protein provide the nutrients mitochondria use, including B vitamins, magnesium and iron. Avoiding a constant surplus of sugar and ultra-processed food reduces metabolic strain on the mitochondria in muscle and liver.

Is there a test for mitochondrial health?

There is no simple routine blood test for mitochondrial health in healthy people. Specialist tests, including genetic testing and muscle biopsies, are used to diagnose rare mitochondrial diseases. Fitness measures such as VO2 max give an indirect picture of aerobic capacity. Persistent fatigue should always be assessed by a doctor first to rule out other causes.

Do NAD+ supplements improve mitochondrial health?

NAD+ precursors such as NR and NMN raise NAD+ levels in human studies, but consistent improvements in mitochondrial function, energy or long-term health have not yet been clearly shown. Larger and longer trials are still needed. Anyone considering these supplements should speak to a doctor, particularly if they take regular medication or have a health condition.

How long does it take to improve mitochondrial health?

Muscle mitochondria begin adapting to regular exercise within a few weeks, and studies commonly measure clear changes over 8 to 12 weeks of consistent training. At Swastik Wellbeing Sanctuary in Khadakwasla, Pune, the Cellular Vitality and Longevity programme recommends a minimum stay of 7 to 14 days as a reset, with the routine continued at home.