By Rodolfo Giacoman, Fatigue Management Specialist, Commercial Vehicle Safety Alliance
Originally published in the 2026 First Quarter Guardian, Page 36

• Unlock the #2 predictor of driver wellness: VO2 max rate — the measurable edge that beats conventional risk factors and shields fleets from fatigue-related costs.
• Learn practical, low-impact protocols (Zone 2, HIIT) and road-ready exercises that boost cardiovascular resilience for drivers on the clock.
• Implement data-driven fitness strategies to extend healthspan, reduce downtime, and lower fleet risk.

Estimated read time: 6 minutes.

If you have seen my presentations, chances are you heard me say that the single most important predictor of well-being and longevity is positive personal relationships. I was surprised to learn how our social interactions have such an overwhelming impact on our physical health. The underlying reason is that warm relationships are a powerful stress regulator. If you are interested in the scientific evidence validating it, please see the sidebar piece and check out the fourth quarter 2023 “Guardian” article, “The Alertness Equation: How Positive Relationships Add Up.”

So, based on that, should we just concentrate on positive relationships and forget about mindfulness, exercise, nutrition and sleep hygiene? Should we just party with others, including drinking alcohol and smoking? Don’t I wish.

Wellness and longevity, just like fatigue, are multifactorial. And while maintaining positive relationships may be the most important factor, it is not the only one. The second single most important predictor of wellness and longevity is cardiorespiratory fitness measured by the “VO2 max rate.” VO2 max is the maximum volume of oxygen our body can utilize during intense or maximal exercise. It measures how many milliliters (Volume) of oxygen (O2) our body can process per minute.

Solid Predictor of Longevity

Large-scale studies, including a landmark 2018 study published in JAMA Network Open involving over 120,000 participants, found that cardiorespiratory fitness, measured by VO2 max, is a stronger predictor of death than traditional risk factors like smoking, diabetes or high blood pressure.

The data suggests that the higher our VO2 max, the lower our risk of premature death. Most notably, there appears to be no ceiling to this benefit as extreme fitness is associated with the lowest risk of mortality.

Healthspan vs. Lifespan

While VO2 max predicts how long we will live (lifespan), it is even more critical for healthspan, the period of life spent in good health. VO2 max naturally declines with age, roughly 10% per decade after age 30. By starting with a higher peak, we ensure that even after decades of decline, we remain above the threshold of frailty.

High aerobic fitness is linked to better insulin sensitivity and mitochondrial function, significantly lowering the risk of Type 2 diabetes and metabolic syndrome, a group of conditions that increase the risk of heart disease, stroke and Type 2 diabetes. The evidence shows that improving VO2 max provides a protective effect across multiple systems.

It reduces arterial stiffness and strengthens the heart muscle, thereby lowering the risk of stroke and heart attack. Higher fitness levels are correlated with a lower risk of dementia and Alzheimer's disease, likely due to increased blood flow and oxygen delivery to the brain. Higher VO2 max levels are associated with lower rates of certain cancers, particularly lung and colorectal cancers.

For drivers, VO2 max acts as a physiological buffer. A high VO2 max means that the cost of daily life (walking, lifting, staying alert) represents a smaller percentage of total capacity. This results in less systemic stress, lower cortisol levels and better recovery from the physical demands of the driving task.

What It Actually Measures

VO2 max measures the efficiency of our entire oxygen supply chain, from the moment we take a breath to the moment that oxygen is converted into energy in our muscles. Here are the five stages of the oxygen supply chain system from a logistics perspective:

The Oxygen Supply Chain System

When measuring VO2 max, we are measuring the total capacity of this system to move oxygen from the port of entry all the way to the factory at peak demand. If any single stage of this supply chain reaches its limit, the VO2 max rate will plateau.

Methods to Measure or Calculate VO2 Max

Laboratory vs. Clinical Standards

The Metabolic Cart and Bruce Protocol are the most rigorous. While the Metabolic Cart measures actual gas exchange, the Bruce Protocol uses a specific treadmill formula. These are excellent for drivers who need a definitive medical-grade baseline for their health records or U.S. Department of Transportation (DOT) exam readiness. (See Important Safety Notice.)

Performance-Based Estimates

The Cooper 12-Minute Run and Beep Test use high-intensity performance to work backward and predict oxygen use. These are great for drivers who are already active and want a benchmark of their engine's maximum power without needing a lab. (See Important Safety Notice.)

Low-Impact and Accessible Methods

The Rockport Walk and Step Test are the most practical for life on the road. They provide a solid estimate of your cardiovascular health without requiring you to run at full speed, making them safer to perform at a truck stop. (See Important Safety Notice.)

Data-Driven and Stationary Calculations

The CERG Calculator is a research-based desktop method. It requires zero physical exertion, using population data to estimate your fitness based on your age, BMI, resting heart rate and exercise habits.

The Heart Rate Ratio is the most convenient calculation of all. By simply knowing resting and maximum heart rates, we can get a quick ballpark figure of the heart's efficiency anywhere.

Continuous Monitoring

Wearables (watches, rings, etc.) calculate the trend of your supply chain efficiency over months. For a driver, seeing this score improve over the long haul is a great sign that the cardiovascular system is becoming more resilient.

How to Improve VO2 Max

To upgrade your oxygen supply chain, you need a two-pronged approach: Building a massive infrastructure (Zone 2 training) and upgrading your loading cranes (high-intensity interval training (HIIT)). (See Important Safety Notice.)

Building Infrastructure: Zone 2 Training

Zone 2 is low-intensity, steady-state cardio exercise where one can hold a conversation uncomfortably without gasping for air. For drivers, this is the most sustainable way to train. The goal is to build more local infrastructure, or capillaries, and more factories, or mitochondria. Zone 2 training makes our bodies better at burning fat for fuel. This keeps our energy levels stable during a long day shift and prevents energy crashes that lead to fatigue.

Drivers should start with 30-45 minutes and increase it gradually, three to four times a week. Heart rate should stay at roughly 60-70% of maximum or when it is still possible to speak entire sentences, but uncomfortably. 

Upgrading Loading Cranes: HIIT Training

HIIT involves short bursts of maximum effort followed by recovery. The goal is to upgrade the loading cranes or heart. HIIT forces the heart to pump the maximum amount of blood possible per beat, which physically stretches and strengthens the heart chambers, increasing stroke volume. This raises the ceiling. It makes physical tasks – like tarping a load or cranking a landing gear – feel significantly easier because your heart is now over-indexed for the task.

Drivers should start with 2-4 minutes of hard effort, followed by 1-3 minutes of easy movement. Repeat this at least four times. Doing this once or twice a week will result in observable gains in VO2 max.

Efficiency Barrier: The Lactate Threshold

While VO2 max is the total horsepower, the lactate threshold determines how much of that power can be used for a long time. Lactate is a byproduct of energy production. At lower intensities, the body clears it as fast as it makes it. But as we push harder, we hit a point where lactate builds up in the blood faster than we can remove it, and this is the Lactate Threshold.

If our threshold is low, we will feel burned out and physically exhausted very quickly. By doing both Zone 2 and HIIT, we push our threshold higher. This allows us to work at a higher percentage of VO2 max without redlining the system.

Sample Exercises for the Road*

If you have not been exercising regularly, starting any exercise program will help. Knowing about the benefits of improving your VO2 max should give you a very good reason to get started. Please check out the fourth quarter 2024 “Guardian” article, “Maintaining Our Most Important Asset,” for general information on how to go about exercising. 

Please keep your questions and comments coming at rodolfo.giacoman@cvsa.org.

Important Safety Notice

The information provided here is for educational and informational purposes only and is not intended as medical advice. VO2 max testing, especially high-intensity protocols like the direct lab test, Bruce Protocol, Cooper Run or Beep Test, places significant stress on the cardiovascular and respiratory systems.

Before attempting any VO2 max test, starting a new exercise program or changing your physical activity level, you must consult with a qualified healthcare professional (such as a doctor, cardiologist or U.S. DOT medical examiner). This is especially critical if you:

• Have a history of heart disease, high blood pressure or respiratory issues.
• Are managing chronic conditions like diabetes or obesity.
• Experience chest pain, dizziness or shortness of breath at rest or during activity.
• Have been sedentary for a long period.

Stop exercising immediately and seek medical attention if you feel any discomfort, unusual pain, lightheadedness, nausea or extreme fatigue during a test or workout. Your safety and long-term health are more important than any fitness score.