Why midlife energy isn’t about willpower - It’s about your mitochondria

MitoQ’s Chief Science Officer joins the High Performance Health podcast with Angela Foster  

When it comes to cutting through the noise around mitochondria, inflammation and midlife energy, few people explain it as clearly, or as practically, as our MitoQ Chief Science Officer, Dr. Siobhan Mitchell. In her recent conversation with High Performance Health host Angela Foster, Dr. Mitchell dives deep into what really drives energy, resilience, recovery and brain health as we age - and why supporting your mitochondria is one of the most meaningful things you can do for long-term wellbeing. 

In the episode, Dr. Mitchell reframes mitochondria not as simple “battery packs,” but as master regulators that orchestrate oxidative stress, immune signalling and cellular ageing. She also explains the difference between hormetic stress (the kind that upgrades you) and chronic stress (the kind that drains you) - and what women in midlife especially need to know about NAD, inflammation and brain resilience. 

What are the key themes of the podcast?  

Angela invited Dr. Mitchell on the show to help listeners understand why energy often feels lower in midlife, even when you’re doing everything right - eating well, training consistently, and prioritising sleep. 

Dr. Mitchell explains how: 

• Mitochondria become less efficient, more stressed, and slower to renew. 
• Chronic stress and inflammation place additional strain on your cellular energy system, especially during perimenopause and menopause. 
• NAD levels naturally decline with age, leaving your cells with less capacity to create energy and repair themselves. 
• The inflammation-mitochondria connection 
• During menopause, loss of estrogen can significantly reduce mitochondrial efficiency in the brain. 
• The role MitoQ’s mitoquinol mesylate can play in supporting  

Her goal? To help people move beyond generic “boost your energy” advice and instead understand the underlying biology - so they can work with their bodies, not against them. Read more about each of these points below. 

What are mitochondria really doing inside your cells? 

Most of us learned in high school biology that mitochondria are the “powerhouses of the cell.” But as Dr. Mitchell explains, that’s only part of the story. 

Mitochondria create up to 95% of your body’s energy - but generating that energy also creates oxidative stress. 

Over time, this oxidative stress can damage mitochondrial membranes, proteins and mitochondrial DNA (mtDNA), reducing efficiency and accelerating biological ageing. Normally, your body manages this through antioxidant enzymes and mitochondrial recycling (mitophagy), but these processes decline with age. 

That’s when people begin to feel: 

• Lower day‑to‑day energy 
• Slower recovery 
• Greater susceptibility to stress 
• Brain fog and cognitive changes 

And for women in midlife, a drop in estrogen adds another layer, because estrogen directly supports mitochondrial function in the brain. 

What’s the difference between “Good Stress” and “Bad Stress”? 

Not all stress harms your cells. In fact, some stress actually makes you more resilient. 

Hormetic stress (good stress) 

This includes things like: 

• Exercise (especially zone 2 and high‑intensity efforts) 
• Cold exposure 
• Sauna 
• Certain plant compounds (polyphenols) 

Hormetic stress signals your mitochondria to upgrade themselves — triggering mitochondrial biogenesis, improved oxygen efficiency, and stronger resilience. 

Chronic stress (bad stress) 

This includes: 

• Mental load and emotional stress 
• Environmental toxins 
• Poor sleep 
• Inflammation 

These stressors don’t allow for recovery - which means your mitochondria keep producing oxidative stress without the opportunity to repair. 

Over time, this leads to mitochondrial dysfunction and makes your cells less able to respond adaptively to future stress. 

How NAD fits into the energy and aging story 

NAD is a coenzyme your cells use to: 

• Create ATP (cellular energy) 
• Repair DNA 
• Support healthy inflammatory responses 
• Activate longevity pathways (sirtuins) 

But NAD levels decline by roughly 50% by your 40s — which is why many people notice a shift in energy, focus and resilience at midlife. 

• Dr. Mitchell breaks down why NAD precursors alone aren’t always enough: 
• Most NR/NMN is converted into nicotinamide first 
• The body needs an enzyme called NAMPT to convert it into usable NAD 
• Without good NAMPT activity, or healthy mitochondria, much of the precursor can be wasted 

This is why Dr. Mitchell emphasises a systems approach: supporting both NAD production and mitochondrial function at the same time. 

The inflammation–mitochondria connection 

One of the most fascinating parts of the episode: mitochondria play a major role in immune signalling. 

When mitochondria are stressed or damaged, they release signals (including mtDNA and reactive oxygen species) that activate the immune system. When this response becomes chronic, it can contribute to: 

• Cytokine storms 
• Accelerated biological ageing 
• Neuroinflammation 
• Metabolic dysfunction 
• Autoimmune fatigue 

This helps explain why so many people experiencing chronic inflammation also struggle with energy production and why improving mitochondrial health can help support immune balance. 

Mitochondria & women’s brain health in midlife 

Dr. Mitchell highlights one crucial message: 

"During menopause, loss of estrogen can significantly reduce mitochondrial efficiency in the brain."

This shift contributes to: 

• Brain fog 
• Night sweats 
• Cognitive slowing 
• Mood changes 
• Reduced stress tolerance 

Supporting mitochondria, especially with ingredients that target oxidative stress and NAD pathways, can help maintain cognitive clarity and protect long‑term brain health. 

The unique role MitoQ plays in cellular health 

What makes MitoQ truly unique is its hero ingredient, mitoquinol mesylate, a form of CoQ10 that’s been biochemically engineered to cross the mitochondrial membrane and accumulate directly where oxidative stress begins. This is something standard antioxidants and even CoQ10 itself struggle to do, because very few compounds can actually enter the mitochondria. By reaching this space, mitoquinol mesylate helps support mitochondrial resilience. This is especially meaningful for women in midlife, when declining estrogen, increased inflammation, and accelerated drops in NAD can all converge to make energy, focus, and recovery feel harder.  

By helping mitochondria manage oxidative stress more effectively, MitoQ supports clearer thinking, steadier energy, and healthier cellular ageing during a stage of life when the body’s natural defences start to slow down. 

This is why many people report improvements in: 

• Day‑to‑day energy 
• Recovery from training 
• Mental clarity 
• Stress resilience 

Discover MitoQ Pure 

As highlighted in the podcast, MitoQ Pure contains our world first ingredient, Mitoquinol  mesylate, that delivers science-backed benefits that go beyond ordinary antioxidants. Proven to get deep into cells to combat the root causes of aging and support cellular longevity, metabolism, healthier aging, and sustained energy. 

Learn more 

Frequently Asked Questions 

Why does energy often drop in midlife? 

Because NAD levels decline, mitochondrial efficiency decreases, and chronic stress becomes harder to recover from - all of which reduce cellular energy capacity. 

Can you “fix” low energy by exercising more? 

Not always. Without healthy mitochondria and adequate NAD, more training can feel draining rather than energising. 

What’s the biggest mitochondrial stressor? 

Chronic, unresolved stress - whether emotional, inflammatory, or environmental. 

Why are women in perimenopause especially affected? 

Estrogen supports mitochondrial function in the brain. When estrogen declines, mitochondria become less efficient and more prone to oxidative stress. 

Listen to the full conversation here.

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