When it comes to jogging, less is more, according to a recent study by Danish researchers, who found that running excessively is as good as not exercising.
It found that people jogging at a slow or moderate pace had the lowest rates of death, while those who jogged frequently and strenuously were just as likely to die as people who did not jog at all.
The study found that light jogging at a steady pace of 8kmh, meaning 18 minutes for a 2.4km run, is healthier than vigorous runs at speeds of 11.3kmh.
Jogging a total of one to 2.4 hours per week, no more than thrice weekly, is best for a long life, said the study published in the Journal of the American College of Cardiology on Monday.
The fresh findings support some past studies, which suggested that vigorous endurance activities may cause health problems, especially to the cardiovascular system.
However, several doctors and runners interviewed said the study should not deter individuals from regular runs.
"The wrong take-home message from this research is that being sedentary is just as good as doing high-intensity exercise," said Dr Cindy Lin from Changi Sports Medicine Centre at Changi General Hospital. "The benefits of moderate- to vigorous-intensity exercise have been well documented in the literature."
Middle- to long-distance runner Colin Tung, 26, who is training for the 3,000m steeplechase event at the SEA Games, said he will not run any less because of the study. "I am not overly concerned with the findings," said the freelance writer, who trains about six days a week. "The health benefits I have gained from running are more concrete than what this study has proven."
For the study, participants had to self-report things such as their jogging frequency and duration, and their perception of pace. The findings were based on data from the Copenhagen City Heart Study, and tracked 1,098 healthy joggers and 413 healthy but sedentary individuals for 12 years.
However, the study was limited by factors such as the small sample of high-intensity joggers. Of the thousand or so joggers who took part, only 127 were identified as strenuous joggers.
SEA Games marathon champion and doctor Mok Ying Ren believes the optimal dose of exercise varies from person to person. "It is important to listen to your body," said Dr Mok, who is doing his national service as a medical officer. "For exercise, moderation is key. If the goal is just to maintain a healthy lifestyle, exercising five times per week, for 30 minutes each time, is enough."