Which Age Group is the Most Fit?

What determines fitness? Keep scrolling to find out!

Data

Our data was extracted from the Treadmill Maximal Exercise Tests conducted by the Exercise Physiology and Human Performance Lab of the University of Malaga, available through PhysioNet's Open Databases.

In these tests, each athlete performed a maximal Graded Exercise Test (GET) on a PowerJog J series treadmill connected to a CPX MedGraphics gas analyzer system. The device recorded breath-by-breath measurements of key cardiac and respiratory parameters, while heart rate was collected using a Mortara 12-lead ECG device.

Athletes ran on the treadmill using either a continuous (ramping) or a step-by-step incremental protocol until exhaustion. Most exercise phases were preceded by a warm-up period of walking at 5 km/h. A test was considered maximal when the participant’s oxygen consumption (VO₂) plateaued.

Our visualizations group participants into six age groups and aggregate their average measurements across each group.

The dataset used for these visualizations contains an inproportionate representation of data for female and individuals aged 60-70. As a result, insights derived from these demographics may not be fully reflective of the broader population.

Watch Our Introduction Video

Run simulation below to see running duration and

oxygen consumption of each age group.

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(10-20] Representative

Contestant #1

(20-30] Representative

Contestant #2

(30-40] Representative

Contestant #3

(40-50] Representative

Contestant #4

(50-60] Representative

Contestant #5

(60-70] Representative

Contestant #6

Active Contestants

    Young athletes run fast, and their speed is impressive, making it easy to assume they are the fittest. Their ability to reach high velocities on the treadmill highlights their youthful energy and quick muscle response. But speed alone doesn't define fitness. Let's take a look at the graphs below.

    Hover over the titles of the graphs to get a definition of each performance metric!

    So, What’s the Truth About Fitness?

    While younger athletes can accelerate quickly, they do so at the cost of higher heart rates, increased respiratory effort, and less efficient oxygen utilization. Their bodies demand more energy and oxygen to sustain their pace, leading to faster exhaustion and suboptimal endurance.

    Therefore, when we look beyond just speed and consider endurance and cardiovascular efficiency, a different picture emerges. Athletes in the 30–50 age range may not be the fastest, but they demonstrate better overall fitness. Their heart rates remain lower, their breathing is more controlled, and their bodies are more efficient at using oxygen. This means they can sustain exercise for longer periods before reaching exhaustion, making them better suited for endurance-based activities.

    In other words, while youth provides the advantage of speed, middle age offers the benefits of efficiency and endurance. So, if we redefine fitness to include not just how fast someone can run but also how well their body sustains activity, the 30–50 age group stands out as the fittest overall.

    It's never too late to be fit!!