Decades of aerobic exercise linked to greater vitality capacity in older adults

Two individuals may mark the same birthday, yet their bodies may have aged in markedly different ways.

One person may retain a greater physiological reserve to call upon. Scientists refer to this underlying reserve as vitality capacity.

A new study indicates that one well-known behaviour is linked with having more of it: maintaining aerobic exercise over several decades.

Researchers at Université Côte d'Azur in France found that healthy adults aged over 55 who had exercised consistently for 30 years showed greater vitality capacity than inactive counterparts.

The most pronounced contrast was not in muscular strength, but in the timing between heartbeats and blood-oxygen levels. These were assessed while participants rested and classified by the researchers within immune and stress response.

This finding does not prove that exercise was responsible for the difference.

Vitality capacity and healthy ageing

Conversations about healthy ageing frequently centre on illness. Vitality capacity considers another question: how much reserve is left in the systems that enable the body to operate when under strain?

The World Health Organization includes this reserve within a person's physical and mental ability. Vitality capacity covers immune and stress response, energy and metabolism, and nerve and muscle function.

To investigate the link, the researchers recruited 39 adults from the Nice region, whose average age was approximately 64. No participant had a chronic condition or took medication.

Nineteen participants had undertaken aerobic activity at least three times weekly for 30 years. Each completed a minimum of 2.5 hours of moderate exercise per week, or half as much vigorous exercise.

The remaining 20 participants took part in no regular exercise or sport and reported spending no more than 75 minutes each week being active during leisure time or travel. Questionnaires and a wearable sensor verified the difference in their current activity levels.

How aerobic exercise was assessed

The researchers brought together 12 measurements - including blood markers, heart rhythm, muscle strength and lung function - to create one vitality score.

After combining these measurements, the lifelong exercisers scored more highly. Scores also generally fell among older participants. However, as each person was measured only once, the researchers could not determine whether vitality capacity decreased over time in the same individuals.

The strongest distinction emerged in two measures recorded at rest.

Participants in the active group had an average blood-oxygen saturation of 96.8 percent, versus 94.8 percent for the inactive group. Their heart-rate variability measured 49.9 compared with 27.2 milliseconds.

Heart-rate variability does not indicate an irregularly beating heart. Instead, it refers to slight differences in the interval between individual beats.

Differences in physiological reserve

However, the active participants did not perform better than inactive participants in every measurement.

There was no clear difference in inflammation markers or in how participants rated their own immune health. The groups also showed no clear differences in grip strength, knee strength or lung function, while no distinct overall gap was identified in energy and metabolism or nerve and muscle function.

The association was therefore focused on specific elements of physiological reserve, rather than demonstrating that lifelong exercisers performed better in every area.

Exploratory comparisons by sex suggested that active women had greater lean mass and lower body fat than inactive women. Comparable differences were not found among men.

Vitality capacity was not linked to reported quality of life either. Scores tended towards the upper end of the scale, potentially making any relationship more difficult to identify.

This was a small exploratory study, and people who remain active throughout life may differ from inactive people in their genetics, social and economic circumstances, or other habits.

Despite doing little exercise, the inactive group was also unusually healthy, which may have caused the groups to appear more alike. Every participant was healthy, older and White, so the findings may not apply to other populations.

The vitality score is itself new and has not been validated as a clinical assessment. Two blood markers were selected from four candidates using the same dataset, which may make the score seem more robust than it is. Repeating the analysis with alternative markers, however, gave largely similar findings.

Nor can the study establish the ideal form or amount of exercise, or determine whether taking up activity later in life would lead to the same pattern. Research following people over time, alongside trials assigning people to exercise, will be required.

For now, the conclusion is more limited: in this small sample of healthy older adults, decades of aerobic activity were associated with greater overall physiological reserve, with heart-rate variability and blood-oxygen levels providing the clearest signal.

The study was published in GeroScience.

This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. Although we take pride in our process, we are only human. If you notice an error, please let us know.