The importance of regular aerobic exercise for all age groups should be highlighted through public education, schooling and the provision of exercise and sporting facilities, according to Prof Risteárd Mulcahy.
His new book Improving With Age - What Exercise Can Do For You examines the increasingly sedentary lifestyle of Irish people and the dangers associated with growing physical inactivity.
"We are becoming a nation of spectators rather than participants of sports," warns Prof Mulcahy.
"Increasing consumerism and this obsession with improving our standard of living has meant that Irish people are taking less exercise; this in turn is leading to a number of serious problems such as the prevalence of obesity, diabetes, heart disease, arthritis and cancer in this country," he says.
To combat the problems associated with lack of exercise, Prof Mulcahy stresses the need for a more proactive approach in promoting the importance of regular exercise.
"There needs to be governmental and legislative actions taken to make it easy and enjoyable for people of all ages to take aerobic exercise," he says.
The focus should be to develop facilities for people to exercise and play sport rather than just to view sports, he says.
"For example, we should have adequate cycle pathways everywhere, facilities for walking and running should be improved and, at the same time, we need to look after our countryside and make sure we're not damaging our environment."
An eminent cardiologist, Prof Mulcahy set up and was head of the cardiology unit at St Vincent's Hospital, Dublin, for many years.
Throughout his career, he has been outspoken about the importance of preventative healthcare and effective health promotion.
In 1966 he set up the Irish Heart Foundation and has always been active in campaigning for public health issues, in particular the dangers of smoking. Now in his early 80s, he continues to advocate the importance of healthy living and taking regular exercise.
In his latest book - part memoir and part practical guide - he highlights the benefits of regular exercise for older people and its role in ensuring a healthier and more independent lifestyle in later years.
"The elderly population have the most to gain from taking regular aerobic exercise," he says.
"As well as the physical benefits of exercise, it also has tremendous psychological and emotional advantages which are beneficial to people, particularly as they get older and may feel more isolated and prone to mood changes."
As well as promoting the benefits of exercise for older people, Prof Mulcahy expresses concerns about the health system's treatment of older people, particularly in light of an ageing Irish population, a trend which is accelerating.
"Ageing is inevitably associated with some negative physical symptoms.
"The danger is that older people become over-medicalised for inappropriate reasons and, as a result, too many old people become dependent on the medical profession," he continues.
"Also, the combination of a growing aged population and the increasing use of high-tech medicine makes it virtually impossible to adequately finance our health services," Prof Mulcahy adds.
"For example, having an old person who has had a stroke or who has severe arthritis or other chronic disabilities associated with old age, for 10 years or more on dependency is extremely expensive.
"Unless increased longevity is accompanied by good health, the demands on health services will continue to grow beyond our resources.
"The only way you can reverse this problem is to ensure that older people remain healthy so that you can shorten the period of disability in old age," he adds.
As someone who has always enjoyed the benefits of exercise and healthy living throughout most of his life, Prof Mulcahy is still physically active in his 80s and walks, cycles and plays golf every week.
In his book, he recounts his experiences of the different sports he was active in and the benefits of a physically active life, notably in later years.
"Exercise has helped me maintain my physical capacity into my 80s; it has also had a hugely important psychological and emotional effect on me throughout my life," he says.
"As a result, the last 15 years of retirement have been a wonderful part of my life because I've been fit and active and able to get involved in the things I enjoy."
• Improving With Age - What Exercise Can Do For You is published by Liberties Press and is available in shops.