You exercise regularly. You feel fitter. Your blood pressure may improve. You become stronger and have more energy.
Then you repeat a biological age test — and the number barely changes.
Does that mean the exercise is not working?
No.
A biological age score is only one part of the picture
Biological age tests are designed to measure selected changes associated with aging.
But aging is extraordinarily complex. It affects the cardiovascular system, metabolism, muscles, brain, immune system and many other parts of the body.
No single biological age test captures all of these changes.
This means that your health can improve even when one biological age measurement stays relatively stable.
Exercise affects much more than a biological age score
Regular physical activity is associated with a lower risk of cardiovascular disease, type 2 diabetes and premature death.
It also helps preserve muscle strength, physical fitness, mobility and independence as we get older.
These are not simply numbers on a laboratory report. They directly influence how well we are likely to function later in life.
This is one reason physical activity remains such an important part of healthy aging.
What do biological age studies show?
Research involving more than 145,000 people found that people who were more physically active generally showed more favourable biological aging profiles measured through changes in DNA.
But the results were not identical across all biological age measures.
Some showed a significant relationship with physical activity. Others did not.
That tells us something important: different biological age tests capture different parts of the aging process.
A test that does not change does not necessarily mean that your body is receiving no benefit from exercise.
Look beyond one number
If you are trying to understand whether your health is improving, biological age can be one piece of information — but it should not stand alone.
Changes in cardiovascular fitness, blood pressure, glucose control, body composition, muscle strength and physical function can all provide valuable information about how your health is changing.
For longevity, the goal is not simply to achieve the youngest possible number on a biological age test.
The larger goal is to remain healthy, capable and independent for as long as possible.
Exercise helps us work toward that goal — whether or not every biological age measurement changes.
Based on Research
Shan J, Tay JH, Wang W, et al. Physical activity and biological age measured by DNA methylation clocks: a systematic review and meta-analysis. The Lancet Healthy Longevity. 2026.
