Running Efficiency Dashboard

Are You Optimzing Your Runs?

What is RER and why does it matter?

The Respiratory Exchange Ratio (RER) measures whether your body is burning fats or carbohydrates during exercise.

RER = VCO2 / VO2

When RER approaches 1, your body shifts from burning primarily fats to burning carbohydrates.

How does RER affect my performance?

Understanding your RER transition point is crucial because it directly impacts:

  • Endurance capacity
  • Fat burning efficiency
  • Recovery time
  • Overall performance

Burning carbs too early can cause you to "hit the wall" before burning optimal fat.

What data is being analyzed?

This visualization uses data from the "Treadmill Maximal Exercise Tests" study [1] from the University of Malaga.

The dataset includes:

  • 846+ runners of various fitness levels
  • Ages 10-63 years
  • Both amateur and professional athletes
  • Breath-by-breath measurements during incremental treadmill tests

How to Use This Graph

Use the filters to explore RER distributions across different demographics. Combinations with fewer than 100 data points won't be displayed.

1 Select demographic filters from the left panel
2 Observe how the distribution changes based on your selections
3 Hover over bars to see detailed values

Population Filters

What Does This Graph Tell Us?

How do demographics affect RER?

The histogram shows how frequently different RER values occur in your selected population. After some exploration, you can see that the distribution moves around significantly according to the selected demographic.

This suggests these variables (gender, age, weight, height) impact how your body uses energy during exercise.

Why does this matter for my training?

Because your demographic affects the RER values, you may not be optimizing your runs according to your body and goals:

  • Your fat-burning zone could differ from generic guidelines
  • You may be hitting runner's wall earlier than you want

What will the next visualization show?

The scatterplot below dynamically illustrates:

  • How RER changes with speed and time for your demographic
  • Predictions of RER using regression models based on your demographic
  • Interactive drawing tools to explore custom workout plans

How to Use This Graph

This interactive scatterplot lets you personalize and visualize how your RER changes during exercise based on your unique demographics.

1 Enter your personal information in the form
2 Click "Calculate RER" to see your personalized prediction
3 Right-click and drag to draw a custom running plan line
4 Observe how the RER values change along your custom path
5 Use "Erase Plot" to clear your drawing and try different paths

Calculate Your Personal RER

Key Takeaways & Applications

What patterns should I look for?

The data reveals several important patterns:

  • Slower, steady runs maintain low RER values (prioritizing fat burning)
  • Faster runs quickly increase RER (shifting to carbohydrate burning)

You can find that transition from fat to carbs happen at different rates for different demographics.

Therefore, people should adjust their pace according to their demographic

How can I apply this to my training?

This visualization allows you to:

  • Tailor workouts to your specific fat-burning zone
  • Optimize your pace for endurance or performance goals
  • Design progressive training that respects your metabolic transitions
  • Make evidence-based decisions about intensity and duration

The interactive drawing feature lets you test different workout strategies before trying them.

What are the limitations?

While powerful, this tool has some constraints:

  • Limited data for certain demographic combinations
  • Environmental factors (temperature, humidity) aren't accounted for
  • Individual variations may exist beyond demographic predictions
  • Training history and fitness level create additional variability

Use these insights as a starting point for personalization, not absolute rules.