Fitness comparison

Fitness age

Cardiorespiratory fitness translated into an age comparison.

AI-assisted editorial draft · Source check: 6 September 2026 · Independent reviewer: not yet assigned

Method evidence: Unrated. Assessment pending. This is a provisional editorial assessment of the stated method, not an endorsement of a test provider.

What it measures

A fitness measure or estimate compared with age-related reference values. It does not measure whole-body molecular aging.

Source 1: Norwegian University of Science and Technology / CERG

Required inputs

Depending on the method, directly measured or estimated VO₂max, physical activity, resting heart rate and body measurements.

How it was developed

NTNU’s CERG fitness calculator is an example of a research-based fitness estimation approach.

Source 1: Norwegian University of Science and Technology / CERG

Outcome associations

Cardiorespiratory fitness has been studied in relation to health outcomes. The evidence for the input measure should not be transferred automatically to every age-branded display.

Source 1: Norwegian University of Science and Technology / CERG

Limitations

Estimation error, exercise history and the selected reference population can change the age comparison.

Can you calculate it yourself?

Some research calculators accept non-exercise inputs. A measured exercise test and a questionnaire estimate are different measurements.

Commercial use

No fitness-age provider profile is verified yet. See NTNU’s own explanation for its calculator.

Source 1: Norwegian University of Science and Technology / CERG
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Sources & verification

  1. Fitness calculator and research

    Norwegian University of Science and Technology / CERG · Accessed 2026-09-06