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Accuracy check in PPD Testing - the Traffic Light System

This article explains the traffic light system in the PPD

Updated over 2 weeks ago

The Traffic Light System in the PPD provides quick, visual feedback on the quality of your test results. It works alongside cross-validation to help you assess the accuracy of key performance parameters.

What the Traffic Light System Shows

For each of the following parameters, you’ll see a green, yellow, or red indicator:

  • VO₂max

  • VLamax

  • Critical Power (In Cycling) / Critical Speed (In Running)

Alongside the color indicator, the PPD displays the deviation from expected accuracy:

  • VO₂max: deviation in ml/min/kg

  • VLamax: deviation in mmol/l

  • Critical Power / Speed: deviation in watts (cycling) or m/s (running)

What the Colors Mean

Color

Meaning

Accuracy Level

🟢 Green

Gold Standard accuracy

Accuracy is comparable with best accuracy as reported in scientific literature. Results are acceptable

🟡 Yellow

Typical lab testing accuracy

Typical accuracy of commercial laboratory testing. Results are acceptable

🔴 Red

Less than typical lab level accuracy

Significant less accurate than standard testing. Raw data should be refiewed and /or test redone.

Why It Matters

The Traffic Light System allows you to:

  • Quickly identify which parameters are highly accurate

  • Recognize results that may require caution in interpretation

  • Focus on improving the quality of test conditions for better accuracy

Tip: If you see a red light for any parameter, consider re-running the test under controlled conditions, changing the weight factors if you have reason to do so or checking your equipment setup to reduce measurement errors.

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