Future Sci OA. 2026 Dec;12(1):2670436. doi: 10.1080/20565623.2026.2670436. Epub 2026 May 13.
ABSTRACT
BACKGROUND: Cardiorespiratory fitness (CRF) is a strong predictor of cardiovascular morbidity and mortality. This study aimed to describe age- and sex-specific reference values for CRF in healthy adults in Kazakhstan and to examine age-related changes in key physiological parameters, including peak heart rate and body mass index.
METHODS: The research included 3271 nonsmoking adults aged 20 to 59 years, free of health issues, who performed symptom-limited incremental cardiopulmonary exercise testing on a cycle ergometer between 2018 and 2025. The highest 30-s average value from exercise testing defined peak oxygen uptake (VO peak).
RESULTS: VO peak were lower in older age groups in both sexes. In men, VO peak values was 43.4 ± 7.41 mL/kg/min during ages 20-29 and 38.3 ± 6.32 mL/kg/min during ages 50-59. In women, corresponding VO peak values were 39.2 ± 6.49 and 30.8 ± 5.78 mL/kg/min. Peak heart rate also was lower in older ages (men: 174 ± 11 to 142 ± 8 bpm; women: 179 ± 10 to 143 ± 11 bpm). Simple linear regression results showed that age was a significant predictor of VO peak, BMI, and peak heart rate in both men and women (p < .001).
CONCLUSION: This study provides the first nationally relevant descriptive data on CRF reference values for Kazakh adults.
PMID:42126915 | DOI:10.1080/20565623.2026.2670436