London - If your exercise regime sees you do nothing all week then go racing round the park several times at the weekend, here’s something to stop you in your tracks.
Light jogging is healthier – and safer – than intensive exercise, scientists have found.
A study shows that jogging three times a week is best, for between 20 and 48 minutes each time.
Heavy joggers are as likely to die as those leading a sedentary life, according to the scientists, while light joggers going at a slow or moderate pace had the lowest rates of death.
The research appears to confirm growing evidence that extreme exercise may be bad for you.
Previous studies have suggested that activities such as marathons, ‘iron man’ distance triathlons and very long distance bicycle races may cause structural changes to the heart and large arteries, leading to lasting injury.
The most notorious example of a jogger coming to grief was Jim Fixx, the author of the 1977 bestseller The Complete Book Of Running.
His book is credited with starting the revolution that made running and jogging a daily routine for many. But in July 1987 Fixx died at 52 from a heart attack after his daily run.
In the latest study, Danish researchers tracked 1,098 healthy joggers and 413 healthy but sedentary non-joggers for 12 years.
The study, which examined hours of jogging, frequency, and the individual’s perception of pace, found that strenuous joggers were as likely to die as sedentary non-joggers, while light joggers had the lowest rates of death.
Jogging from one hour to two hours 24 minutes a week was associated with the lowest mortality and the optimal frequency of jogging was no more than three times a week.
Overall, significantly lower mortality rates were found in those with a slow or moderate jogging pace, while the fast-paced joggers had almost the same risk as the sedentary non-joggers.
Researchers registered 28 deaths among joggers and 128 among sedentary non-joggers, says a report in the Journal of the American College of Cardiology.
In general, the joggers were younger, had lower blood pressure and body mass index, and had a lower prevalence of smoking and diabetes.
Peter Schnohr, a researcher from the Copenhagen City Heart Study at Frederiksberg Hospital, said: ‘It is important to emphasise that the pace of the slow joggers corresponds to vigorous exercise and strenuous jogging corresponds to very vigorous exercise.
‘When performed for decades, this activity level could pose health risks, especially to the cardiovascular system.
‘The association between jogging and mortality suggests there may be an upper limit for exercise that is optimal for health benefits.
‘If your goal is to decrease risk of death and improve life expectancy, jogging a few times a week at a moderate pace is a good strategy. Anything more is not just unnecessary, it may be harmful.’
Maureen Talbot, senior cardiac nurse at the British Heart Foundation, said: ‘This study shows that you don’t have to run marathons to keep your heart healthy.
‘Light and moderate jogging was found to be more beneficial than being inactive or undertaking strenuous jogging, possibly adding years to your life.
‘National guidelines recommend we do 150 minutes of moderate intensity activity a week. It may sound like a lot, but even brisk walking is good exercise and if you’re bit of a couch potato this is a good place to start.’
Daily Mail