While it's unlikely that we'll ever get up to the cycling standard of Bradley Wiggins or Victoria Pendleton, but serious cycling could help keep you young, according to new research.
A study of fit amateur cyclists aged 55 to 79 found that many were physically and biologically much younger than most people of the same age.
The 81 male and 41 female participants underwent extensive tests of their heart, lung, neuromuscular, metabolic, and hormonal functions.
Their reflexes, muscle and bone strength, and oxygen uptake were also measured, as well as mental ability and general health and wellbeing.
The results showed that among the cyclists the effects of ageing were far from obvious, with younger and older members of the group having similar levels of muscle strength, lung power and exercise capacity.
In one basic test of falling risk in older people the time taken to stand from a chair, walk three metres, turn, walk back and sit down was recorded.
Taking more than 15 seconds to complete the task generally indicates a high risk of falling. But even the oldest cyclists - those in their seventies - had times that fell well within the norm for healthy young adults.
Professor Norman Lazarus, one of the researchers from King's College London and self-described cyclist, said: "Inevitably, our bodies will experience some decline with age, but staying physically active can buy you extra years of function compared to sedentary people.
"Cycling not only keeps you mentally alert, but requires the vigorous use of many of the body's key systems, such as your muscles, heart and lungs which you need for maintaining health and for reducing the risks associated with numerous diseases."
The cyclists were recruited deliberately to exclude effects from a sedentary lifestyle that may cause changes in the body capable of being confused with those due to ageing.
Men and women had, respectively to be able to cycle 100 kilometres in under 6.5 hours, and 60 kilometres in 5.5 hours, to be included in the study. Smokers, heavy drinkers, and people with high blood pressure or other health conditions were excluded.
Oxygen consumption rate showed the closest association with birth date, according to the results published in the Journal of Physiology. But even this marker could not provide an accurate indication of the age of any given individual.
Study leader Dr Ross Pollock, from King's College London, said: "The main problem facing health research is that in modern societies the majority of the population is inactive.
"A sedentary lifestyle causes physiological problems at any age. Hence the confusion as to how much the decline in bodily functions is due to the natural ageing process and how much is due to the combined effects of ageing and inactivity.
"In many models of ageing lifespan is the primary measure, but in human beings this is arguably less important than the consequences of deterioration in health. Healthy life expectancy - our healthspan - is not keeping pace with the average lifespan, and the years we spend with poor health and disabilities in old age are growing."
Co-author Professor Stephen Harridge, director of the Centre of Human & Aerospace Physiological Sciences at King's College, said: "Because most of the population is largely sedentary, the tendency is to assume that inactivity is the inevitable condition for humans. However, given that our genetic inheritance stems from a period when high levels of physical activity were the likely norm, being physically active should be considered to play an essential role in maintaining health and well-being throughout life."