Houtkamp D; University of Physiotherapy, Amersfoort, The Netherlands.
Pool-Goudzwaard AL; Takken T; Chettouf S; Van de Wiel A;
Bautmans I; Bongers BC

European Journal of Applied Physiology. 126(2):1067-1077, 2026 Feb.

PURPOSE: 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.

METHODS: Cross-sectional data from 611 participants of the AMCOHF study
were analyzed. CRF was assessed via cycle ergometer CPET evaluating oxygen
uptake (VO2peak) and work rate (WRpeak) at peak exercise, oxygen uptake at
the ventilatory anaerobic threshold (VO2VAT), 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 VO2peak
assessed the usefulness of VO2VAT and OUES as submaximal and
effort-independent alternatives for CRF.

RESULTS: All CRF variables declined with age. VO2peak (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 VO2peak and WRpeak (rho
= 0.90), VO2VAT (rho = 0.78), and OUES (rho = 0.87).

CONCLUSION: This study provides reference values for VO2peak, WRpeak,
VO2VAT, 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.