The best exercise to increase mitochondria according to science

HIIT is one of the most effective ways to stimulate mitochondrial biogenesis, the process by which your body creates new mitochondria within cells. HIIT appears to provide a powerful signal that encourages muscle cells to adapt by increasing both the number and efficiency of mitochondria. 

But that doesn't mean HIIT is the only exercise that benefits mitochondrial health. 

Steady-state aerobic exercise, strength training and other forms of movement can also support healthy mitochondria through slightly different mechanisms. The key is understanding how each type of exercise affects your body's energy systems and which approach may best suit your goals. 

Before looking at specific workouts, it's helpful to understand why mitochondria respond so strongly to exercise in the first place. 

Why exercise increases mitochondria 

Mitochondria are often called the powerhouses of the cell because they produce most of the body's ATP (adenosine triphosphate), the energy molecule that powers virtually every cellular process. 

When you exercise, your muscles suddenly need more ATP. To meet that demand, your cells activate several energy-sensing pathways that signal the body to build more efficient energy-producing machinery. One of the most important regulators involved is a protein called PGC-1α, often described as a master regulator of mitochondrial biogenesis. When activated, it helps switch on genes involved in mitochondrial growth, repair and adaptation. 

Over time, repeated bouts of exercise can lead to: 

• Increased mitochondrial density 
• Improved mitochondrial efficiency 
• Better oxygen utilization 
• Enhanced ATP production 
• Greater endurance and stamina 
• Improved cellular resilience 

Having more and healthier mitochondria means your cells become better at producing energy. This may support endurance, recovery, physical performance and healthy aging. Because mitochondria power almost every cell in the body, their function is closely linked to how energetic, resilient and metabolically healthy you feel. This is one reason mitochondrial health has become such an active area of longevity research. 

For a deeper understanding of what mitochondria do and why they're so important, see our article on the essentials of mitochondria. 

Why HIIT is considered the best exercise for increasing mitochondria 

HIIT involves alternating short bursts of high-intensity effort with brief recovery periods. 

Examples include: 

• Sprint intervals 
• Hill sprints 
• Cycling intervals 
• Rowing intervals 
• Fast-paced bodyweight circuits 

During these intense bursts, ATP demand rises rapidly. This creates significant metabolic stress within muscle cells, activating the pathways associated with mitochondrial biogenesis. Research has shown that HIIT can increase markers of mitochondrial content and mitochondrial respiration, often in less time than traditional steady-state exercise. 

One reason HIIT is so effective is that it creates a large energy deficit in a short period. The body responds by upgrading its energy-producing machinery to better handle future demands. 

Potential mitochondrial benefits of HIIT may include: 

• Increased mitochondrial biogenesis 
• Improved ATP production capacity 
• Better insulin sensitivity 
• Improved cardiovascular fitness 
• Enhanced endurance performance 

For people looking specifically to maximize mitochondrial adaptations efficiently, HIIT is often considered the gold standard. 

5 more exercises that increase mitochondria 

While HIIT may provide the strongest signal for mitochondrial growth, it is far from the only form of exercise that supports mitochondrial health. 

The best exercise is ultimately the one you can do consistently. 

1. Aerobic endurance exercise 

Activities such as: 

• Walking 
• Jogging 
• Running 
• Cycling 
• Swimming 
• Hiking 

are highly effective for supporting mitochondrial adaptations. 

During sustained aerobic exercise, your muscles rely heavily on oxygen-dependent energy production. Over time, this encourages the body to increase mitochondrial density and improve the efficiency of existing mitochondria. 

How aerobic exercise differs from HIIT 

HIIT creates intense mitochondrial stress over short periods. 

Aerobic exercise creates moderate mitochondrial stress over longer periods. 

Both increase mitochondria, but aerobic exercise tends to be particularly beneficial for: 

• Cardiovascular endurance 
• Fat metabolism 
• Long-duration energy production 
• Exercise sustainability 

2. Strength training 

When people think about mitochondria, they often think exclusively about cardio. However, resistance training also plays an important role. 

Research suggests strength training can stimulate mitochondrial adaptations while supporting muscle growth and function. HIIT and resistance training have both been identified as exercise types that can stimulate the formation of new mitochondria.  

Examples include: 

• Weight training 
• Resistance bands 
• Bodyweight exercises 
• Functional strength workouts 

How strength training differs from HIIT 

Strength training focuses more heavily on: 

• Muscle recruitment 
• Strength development 
• Muscle maintenance 
• Functional capacity 

while still supporting cellular energy systems. 

This can be especially important as we age, as both muscle mass and mitochondrial function naturally decline over time. 

3. Walking 

Walking may not create the same mitochondrial stimulus as HIIT, but it remains one of the most accessible forms of exercise available. 

Regular brisk walking can: 

• Increase daily energy expenditure 
• Improve cardiovascular fitness 
• Support mitochondrial maintenance 
• Encourage metabolic flexibility 

For many people, walking serves as a sustainable foundation for long-term mitochondrial health. 

If you're new to exercise or rebuilding fitness, walking can be an excellent starting point before progressing to more intense training methods. 

What difference do these exercises make inside the body? 

Although all forms of exercise can benefit mitochondria, they don't challenge the body in exactly the same way.

Think of it like upgrading a power station. 

HIIT encourages the body to build new energy-producing infrastructure quickly. 

Aerobic training improves the long-term efficiency of that infrastructure. 

Strength training helps preserve the muscle tissue that houses many of those mitochondria. 

Walking helps maintain the system and supports overall metabolic health. 

Each exercise contributes differently, but all can support a healthier cellular energy network. 

How long does it take exercise to increase mitochondria? 

Mitochondrial adaptations can begin surprisingly quickly. 

Research discussed in exercise physiology reviews suggests measurable improvements in mitochondrial respiration can occur within a few weeks of structured training, although more substantial changes typically occur with consistent exercise over several weeks and months. 

Consistency is more important than intensity alone. 

A workout performed once may trigger the biological signals involved in mitochondrial growth. Repeated workouts, followed by adequate recovery, are what drive lasting adaptation. 

Other ways to support mitochondria 

Exercise is arguably the most well-supported lifestyle intervention for mitochondrial health, but it's not the only one. 

Other factors that may support healthy mitochondrial function include: 

• Prioritizing sleep 
• Managing chronic stress 
• Eating a nutrient-dense diet 
• Maintaining metabolic health 
• Avoiding smoking 
• Staying physically active throughout the day 

If you'd like to explore additional strategies in more detail, these articles provide a deeper dive: 

How to optimize mitochondrial health for longevity 

Mitochondrial dysfunction: Causes, symptoms and support 

The essentials of mitochondria 

The bottom line 

If your goal is to increase mitochondria as efficiently as possible, high-intensity interval training (HIIT) is likely the best exercise based on current research. HIIT creates a powerful stimulus for mitochondrial biogenesis, encouraging your body to build more robust cellular energy systems. 

However, mitochondrial health isn't built through HIIT alone. 

Aerobic exercise, strength training and even regular walking all contribute to healthier, more efficient mitochondria through different pathways. The most effective exercise plan is often one that combines multiple forms of movement and can be sustained consistently over time. 

The result isn't simply better fitness. Healthier mitochondria may support energy production, endurance, metabolic health and healthy aging, making exercise one of the most powerful tools available for supporting your cells from the inside out.  

FAQ's 

Can exercise create new mitochondria? 

Exercise can stimulate mitochondrial biogenesis, the process by which the body creates new mitochondria inside cells. Research suggests regular exercise, particularly HIIT and aerobic training, can increase both mitochondrial number and function. 

What exercise increases mitochondria the most? 

HIIT is generally considered one of the most effective forms of exercise for stimulating mitochondrial biogenesis and increasing mitochondrial function. 

Can walking increase mitochondria? 

Walking may support mitochondrial health, particularly when performed regularly and at a brisk pace, although the effect is generally smaller than higher-intensity exercise.  

Does strength training increase mitochondria?

Yes. Resistance training can stimulate mitochondrial adaptations while also supporting muscle strength and maintenance. 

How long does it take to build new mitochondria from exercise? 

Research suggests mitochondrial adaptations can begin within weeks of consistent training, with larger improvements developing over months. 

Why are mitochondria important? 

Mitochondria produce ATP, the energy currency used by your cells to support movement, thinking, recovery and countless other biological processes.