The Study
Description of age- and sex-specific reference values for cardiorespiratory fitness in healthy ethnic Kazakh adults: a cross-sectional study
This study measured how fit people are at different ages and found that older people tend to be less fit than younger ones. But it didn’t watch the same people over time, so we can’t say getting older makes you less fit—it just shows that older people in this group were less fit when measured.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at how fit healthy adults in Kazakhstan are when they exercise hard, and found that everyone gets less fit as they age.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this means older adults have weaker hearts and lungs, carry more weight, and can't exercise as hard as younger people, which increases heart disease risk.
- 2Men aged 20–29 had a VO2 peak of 43.4 mL/kg/min; by age 50–59, it dropped to 38.3.
- 3Women dropped from 39.2 to 30.8.
- 4Max heart rate fell from ~175 to ~142 bpm.
- 5BMI rose from ~23.5 to ~26.2 in men and 21.4 to 23.8 in women.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Future Science OA
Year
2026
Authors
A. Beisenbayeva, M. Bekbossynova, F. Bekmetova, G. Zhussupova, U. Aleushinova, A. Abdrakhmanov
Related Content
Claims (6)
People with better cardiovascular fitness have lower resting heart rates and higher heart rate variability.
In healthy urban ethnic Kazakh adults, the highest heart rate reached during maximum physical exertion is lower in people aged 50–59 than in those aged 20–29, with consistent reductions observed in both men and women.
In healthy urban ethnic Kazakh adults, body mass index rises with age. Men's average BMI increases from about 23.5 to 26.2 between ages 20–29 and 50–59. Women's average BMI increases from about 21.4 to 23.8 over the same age range.
In healthy urban ethnic Kazakh adults, older age is associated with lower cardiorespiratory fitness and higher body mass index, with age explaining most of the differences in fitness levels and some of the differences in body mass index.
Healthy adult Kazakhs living in cities have lower aerobic fitness than people in the U.S., Norway, and Brazil, but higher aerobic fitness than people in South Korea and Lithuania.
In healthy urban ethnic Kazakh adults between 20 and 59 years old, aerobic capacity measured by VO2 peak decreases as people get older, with men starting at 43.4 mL/kg/min and dropping to 38.3 mL/kg/min, and women starting at 39.2 mL/kg/min and dropping to 30.8 mL/kg/min.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.