For a few years now mitochondria have been everywhere in endurance talk: "more mitochondria, more performance." The idea isn't wrong — it is far too simple.
What mitochondria actually do
Mitochondria are the power plants of your muscle cells: they use oxygen to produce energy sustainably. The more numerous and efficient they are, the longer a muscle can produce energy without exhausting itself, using more fat and producing fewer fatigue by-products at a given pace.
Why the relationship isn't linear
A 2026 Sports Medicine review invites us to rethink precisely this relationship. Mitochondrial adaptations and performance do not progress at the same rate: some protocols strongly raise mitochondrial markers without improving performance as much, and conversely athletes improve while those markers barely move.
💡 The essential nuance
Mitochondria are one link in the chain. Improving one link isn't enough if another remains the limiting factor.
The other factors that decide performance
- ❤️ The cardiovascular system: how well the heart delivers oxygenated blood.
- 🫁 Breathing and oxygen transport.
- 💪 Strength and musculo-tendinous stiffness: a strong muscle costs less at the same pace.
- 🏃 Running economy and technique.
- ⏱️ Pacing: going out too fast ruins a perfect build-up.
- 🍝 Nutrition and hydration before and during the effort.
- 😴 Sleep and recovery, which govern how training is absorbed.
We cover two of those levers in our articles on sleep and carbohydrate timing.
🎯 Find your real limiting factor
The Full Test (2 h, in Gland) measures strength, power, strength-endurance and asymmetries to see what actually holds your endurance back.
Book my Full TestHow you actually build the aerobic system
No magic recipe: consistent volume at moderate intensity, repeatable week after week, complemented by well-dosed harder sessions. Add strength work — too often neglected by runners and cyclists — which improves movement economy and late-race fatigue resistance.
What to do when you plateau
- • poor race pacing;
- • lack of strength or muscular robustness;
- • insufficient fuelling for the training load;
- • degraded sleep and recovery;
- • monotonous training, always at the same intensity.
🔑 Key point
The right question isn't "how do I grow more mitochondria?" but "what is my limiting factor today?"
Our approach in Gland
We measure first, then target the weak link: strength, intensity tolerance, pacing, nutrition or recovery. The physical preparation programme is then adjusted through retests.
FAQ
Do mitochondria determine my endurance performance?
They contribute but don't decide alone: heart, breathing, strength, technique, pacing, nutrition and recovery matter just as much.
How do you develop mitochondria?
Consistent moderate-intensity volume plus well-dosed hard sessions, over weeks — not one magic workout.
Why am I plateauing despite training a lot?
Because the limiting factor is often elsewhere: pacing, strength, fuelling, sleep. An objective assessment identifies it.
🎯 Stop guessing
A full assessment in Gland, then a plan built around your real brake — not around a trend.
Book my Full TestSources: Botella J., Bishop D.J., Granata C., Mitochondria and Endurance Exercise Performance (Sports Medicine, 2026, DOI: 10.1007/s40279-026-02530-4); Joyner M.J., Coyle E.F., Endurance exercise performance: the physiology of champions (J Physiol, 2008).
