# Reference values for cardiopulmonary exercise testing-derived parameters for cardiorespiratory fitness in Dutch community-dwelling 55- to 75-year-old adults

## TL;DR

This study provides age- and sex-specific reference values for cardiorespiratory fitness in older Dutch adults, improving the accuracy of fitness assessments.

## Contribution

The study establishes novel reference values for CRF parameters in 55- to 75-year-old Dutch adults, accounting for sex, age, and body composition.

## Key findings

- CRF variables decline with age, with V̇O2peak decreasing quasi-linearly by 1.3%/year in females and 2.5%/year in males.
- Significant sex differences were observed in all CRF variables (p < 0.001 for absolute and body mass-corrected values).
- Strong correlations were found between V̇O2peak and other CRF parameters like WRpeak, V̇O2VAT, and OUES.

## Abstract

Accurate interpretation of cardiorespiratory fitness (CRF) requires reference values that account for sex, age, and body composition. Existing reference values often lack these distinctions or exclude older adults. This study aimed to establish sex- and age-specific reference values for absolute and relative (body mass-corrected and lean body mass-corrected) CRF parameters derived from cardiopulmonary exercise testing (CPET) in Dutch community-dwelling 55- to 75-year-old adults.

Cross-sectional data from 611 participants of the AMCOHF study were analyzed. CRF was assessed via cycle ergometer CPET evaluating oxygen uptake (V̇O2peak) and work rate (WRpeak) at peak exercise, oxygen uptake at the ventilatory anaerobic threshold (V̇O2VAT), and oxygen uptake efficiency slope (OUES). Body mass and lean body mass were measured using dual-energy X-ray absorptiometry. Reference values stratified by sex and age were developed using generalized additive models. Prediction equations were generated using multiple linear regression. Correlations with V̇O2peak assessed the usefulness of V̇O2VAT and OUES as submaximal and effort-independent alternatives for CRF.

All CRF variables declined with age. V̇O2peak (L/min) declined quasi-linearly (females: 1.3%/year; males: 2.5%/year). Significant sex differences were observed between all CRF variables (absolute and body mass-corrected values: p < 0.001; lean body mass-corrected values: p < 0.05). Significant correlations were found between V̇O2peak and WRpeak (ρ = 0.90), V̇O2VAT (ρ = 0.78), and OUES (ρ = 0.87).

This study provides reference values for V̇O2peak, WRpeak, V̇O2VAT, and OUES in Dutch older adults aged 55–75 years during cycle ergometer CPET, offering a unique dataset for assessing CRF and monitoring intervention effects.

The online version contains supplementary material available at 10.1007/s00421-025-05978-w.