Unlocking Your Endurance Potential: The Science of VO2max Training

VO2max is the gold standard for measuring cardiovascular fitness, but its relevance extends beyond elite athletes. While Olympic champions, like Kristian Blummenfelt can leverage record-high VO2max on a race day, everyday athletes can benefit in ways that align with real-life demands.

For everyday athletes, enhancing VO2max isn’t just about faster race times; it’s about increasing the body’s ability to deliver oxygen efficiently, improving overall endurance, and promoting long-term well-being. As highlighted in the Athlete’s Compass podcast, everyday athletes face the challenge of balancing training with work, family, and other responsibilities​. Unlike professionals who can prioritize recovery and training as their job, recreational athletes must train smarter, not harder, to see sustainable improvements​.

What is VO2max and Why Does It Matter?

Higher VO2max values are associated with better endurance, lower disease risk, and increased longevity. In fact, research has shown that cardiorespiratory fitness (measured via VO2max) is one of the strongest predictors of overall health and lifespan. 

VO2max is a direct reflection of your body’s ability to use this aerobic system, implying that the more oxygen you can process, the more efficiently your muscles can function (no waste products; the byproducts are simply CO2 and water). Think of it as your engine size—larger is not always superior, but optimizing it for your objectives can significantly enhance endurance and overall fitness.

For everyday athletes, improving VO2max results in:

• Enhanced endurance for running, cycling, rowing and swimming
• Greater efficiency in training with improved oxygen utilization
• Faster recovery and reduced fatigue
• Increased longevity, as VO2max is one of the strongest predictors of lifespan

VO2max: Beyond the Number 

Some athletes become obsessed with the absolute VO2max number, but it is not solely about attaining a high value—it is about how efficiently you can sustain effort at that level. Elite athletes focus on sustaining a high fraction of VO2max, not just improving it. 

For everyday endurance athletes, this means:

• Training should balance high-intensity intervals with steady-state aerobic work
• Developing efficiency at submaximal intensities is just as crucial as peak VO2max
• Improving lactate threshold and fat oxidation assists in maintaining performance over longer distances

The Surprising VO2max Secret of Norwegian Triathletes

What may come as a surprise to many is that the “Norwegian Method” of long-distance triathlon training, practiced by Olav Aleksander Bu, has taken a different approach—one that’s producing world-class results. Instead of hammering high-intensity sessions above VO2max, they rely on double threshold training days, where they complete two controlled lactate-threshold workouts in a single day. Intensity for threshold sessions is just below the traditional VO2max zone but still provides significant aerobic stimulus. 

The surprising part? Even with minimal time spent above threshold, these athletes still develop exceptional VO2max. How? First, their high training volume at low intensity (Zone 1 & 2 in a 5-zone model) expands their heart’s stroke volume, capillary networks, and mitochondrial efficiency, all of which enhance oxygen delivery. Second, their frequent threshold work keeps them operating near VO2max without overloading their system, allowing them to train more consistently without burnout. Finally, their race efforts and occasional VO2max intervals ensure they still hit those top-end intensities when needed, but without the risk of excessive anaerobic fatigue.

Key Takeaways for Everyday Athletes:

• Build a Large Aerobic Base
  Instead of relying on only hard interval sessions to increase VO2max, focus on building a strong aerobic base with high-volume low-intensity Zone 1 & 2 training—at a truly comfortable effort where conversation flows effortlessly.

• Train Smarter with Interval Training
  Add in one or two well-paced threshold sessions per week, keeping the intensity strictly controlled just under the threshold and avoiding deep fatigue. While not the primary focus of the Norwegian triathletes, there is still some VO2max work included. Short HIIT VO2max sessions, like 30/30s maximize VO2max adaptations without overtraining. Everyday athletes can incorporate these workouts once per week to improve aerobic capacity.

• Work with Your Physiology: By staying disciplined with low-intensity efforts and resisting the urge to push too hard, you allow your body to accumulate training without excessive stress. The result? Steady aerobic development. Keeping your easy days easy, you will be able to hit those VO2max sessions and threshold intervals optimally.

By integrating smart VO2max training, even time-constrained endurance athletes can observe measurable improvements without burning out.

Fat Adaptation & VO2max: The Surprising Link

VO2max isn’t just about training; nutrition also plays a role in endurance performance. A lesser-known factor in VO2max performance is the ability to efficiently utilize fat for fuel. Many endurance athletes mistakenly believe that high-intensity training must be fueled exclusively by carbohydrates. However, research suggests that athletes with superior fat oxidation rates can sustain high VO2max outputs for longer durations (Hetlelid et al., 2015).

How This Applies to Everyday Athletes:

• Improving metabolic flexibility (your ability to switch between burning fat and carbs) enhances endurance.
• Low-carb and fasted training sessions can aid in training your body to rely on fat stores without compromising high-intensity performance.
• Superior fat oxidation means reduced dependency on sugary fuels, leading to more stable energy levels during long workouts.

VO2max and Longevity: The Peter Attia Perspective

Dr. Peter Attia, a longevity expert, has highlighted VO2max as one of the strongest predictors of lifespan. His research proposes that maintaining a high VO2max into middle and older age reduces the risk of cardiovascular disease, metabolic disorders, and cognitive decline.

Key Takeaways for Lifelong Fitness:

• VO2max declines with age, but training can decelerate the rate of decline.
• Maintaining cardiovascular fitness into later years is a potent tool for extending healthspan, and staying independent in your older years. Cardiovascular fitness determines how well you can walk up stairs, carry groceries, and recover from illness or injury as you age. High VO2max can determine how long you live, and how well you live.
• Long, steady-state training combined with interval work maintains optimal heart and lung function, reducing the risk of metabolic diseases like diabetes and heart disease.

How to Implement VO2max Training in Your Program

1. Include consistent, year-around VO2max Intervals (1-2x per week)
2. The foundation of VO2max development isn’t actually VO2max training itself—it’s low-intensity volume at Zone 2 intensity.
   

    

   • Keep 80% of weekly volume at low intensity (easy conversational pace). 
   • This builds the aerobic base to sustain high-intensity efforts.
3. Fuel Smartly for Adaptations
   • For fat adaptation, try fasted workouts (Zone 1 & 2 only) to enhance metabolic efficiency.
4. Prioritize Recovery and Adaptation
   • VO2max improvements happen between sessions, not during them, so recovery is critical. Monitor HRV, sleep quality, and subjective energy levels to gauge readiness for hard efforts. Athletica’s daily AI summaries assess your training load and recovery status, helping you know when to push and when to back off. To avoid burnout, space out high-intensity sessions, and listen to your body—if you’re not feeling fresh, adjust accordingly.

Final Thoughts: Train Smarter, Not Harder

A higher VO2max isn’t just for elite athletes—it’s a crucial marker of health and longevity for everyone. Studies have shown that individuals with higher VO2max levels have a significantly lower risk of cardiovascular disease, metabolic disorders, and early mortality.

The key takeaway? Whether you’re training for a race, aiming to stay fit as you age, or simply want to maximize your healthspan, improving your VO2max is one of the best investments you can make in your future.

Start by incorporating a mix of high-intensity efforts, endurance training, and smart recovery. The best training plan is the one that works for you, and at Athletica, we’re here to help guide that process. Instead of relying solely on hard interval sessions, Athletica’s AI-driven coaching system helps structure training with plenty of easy Zone 1 & 2 work, ensuring that intensity stays truly low—where you can comfortably hold a conversation. Athletica’s Workout Reserve feature provides real-time feedback on how much effort you have left in the tank, preventing overexertion and helping you build aerobic capacity sustainably. 

When it’s time for structured threshold work, Athletica’s live and replay VO2max sessions in Velocity allow you to execute workouts with precision. Plus, with daily AI Coach summaries assessing your recovery and readiness, you can train smarter, not harder—ensuring long-term VO2max gains without the risk of burnout.  

Want to find a smarter way to train?Athletica’s AI-powered training plans help optimize VO2max improvement while balancing training load and recovery. 

Sign up today and start unlocking your peak potential.