London, July 21: The question of whether jogging is safe has come up again following the death of the late David Frost's apparently fit 31-year-old son, Miles, who collapsed and died while jogging at the family's home in Oxfordshire.

The expert opinion is that jogging, increasingly being taken up by middle class India where prosperity has also brought obesity, is beneficial for health but has to be pursued with care.

The dangers of jogging are highlighted periodically when young people, who seem to be in the peak of health, suddenly collapse and die.

Friends said there were no indications that Miles, the eldest of the broadcaster's three sons, had any health problems.

David Frost, who was known for his celebrity interviews including one with President Richard Nixon, himself died two years ago, aged 74, after suffering a heart attack on the Queen Elizabeth cruise ship.

Lord Chadlington, a long-standing friend of the Frost family, described Miles as a "healthy man" rather than a fitness fanatic, saying: "He didn't drink alcohol. He clearly led a life where he wanted to be as fit as he reasonably could be, and he liked having a few challenges."

"I had breakfast with him on Thursday and we spent the best part of two hours together," he added. "He was in wonderful form and it is a great shock to his family and friends. It is very sad and very, very sudden. His family are very much in shock."

"I am an investor in some of the companies he was involved in and we were planning what we were going to do in October and November," Chadlington said. "We were looking forward together and there was no hint of anything amiss." Miles leaves behind two younger brothers, Wilfred, 29, a TV presenter on CNBC's Worldwide Exchange programme, and George, 28. All three were educated at Eton.

Last year the three brothers and their mother, Carina Fitzalan-Howard, were joined by 2,000 guests, including the Prince of Wales, for a memorial service at Westminster Abbey in David Frost's memory.

The death of Miles "just underscores the fragility of life", Chadlington observed. "There will be a post mortem examination but all we know is that he collapsed while jogging. It is hard to lose a loved one at any age, but 31 really is difficult to comprehend."

One friend said: "This appears to have come out of nowhere. Miles was in great form recently and seemed really fit and well. It's a terrible shock and everybody feels desperately sorry for his mother and brothers. He was a wonderful man who has gone far too early."

Miles appeared to belong to that class of Englishman who push themselves physically to the limit. He had previously run a half marathon in the Lewa Game Reserve in Kenya, regarded as one of the hardest long distance challenges because of the heat and high altitude.

On social media, there were comments such as: "Running is the cause of many heart attacks."

"Again again and again too much sport is no good," was a further offering. "People push themselves too hard. It's not healthy, better in small doses."

The BBC ran a story, "Could jogging be bad for you?", in 2009 when French President Nicolas Sarkozy collapsed while jogging in Versailles with his wife Carla Bruni. He had engaged in 45 minutes of "intense physical activity" in hot weather.

The BBC asked: "So what are the health hazards associated with jogging?" The benefits far outweigh the risks, according to Andy Dixon, editor of Runner's World magazine.

"At the end of a run, rather than just stopping dead, it's better to run a bit more slowly and slow down until walking fast, allowing the body to adjust gradually back to rest," was his advice.

A more common complaint among runners than fainting is the impact on joints, said Dixon, although the risks should not be exaggerated.

"It's a high-impact activity but the more you do it, the stronger your joints get. There's a fallacy that it wrecks your knees and ankles but there's a long-term study that says the more you do it, it ends up strengthening them."

The Wall Street Journal has carried a feature, "Why So Few Women Jog in India."

"Running as a hobby in India can be intimidating as a female," reported the writer Joanna Sugden, who had moved from London to Delhi.

"You must get used to stares and calls from drivers, cyclists and pedestrians. It's difficult to find clothes modest enough not to offend but cool enough to deal with bath-sized amounts of sweat generated by exercising in 80 per cent humidity."

"But running is becoming more popular for women in India," she said.

She was told by Naina Lal, co-founder of Running Girls India, a support network for women runners, that long distance running was fairly new in India. "But in the last five years it's picked up particularly in the over 40 age group. Health awareness and more people have learnt that it can benefit you and it's not going to break your knees."