Live longer by walking faster

16th December 2011 - Men aged 70 and older can elude the Grim Reaper by walking at speeds of at least 3 miles (or 5km) an hour, according to a study in the BMJ's Christmas issue published on bmj.com today.

The study authors say that for the first time they have estimated the speed at which the Grim Reaper usually walked: about 1.8 miles per hour. He never walked faster than 3 miles per hour.

The Australian study

The Grim Reaper is a well known literary figure who personifies death. There's plenty of anecdotal evidence about him but little scientific research so a team based at Concord Hospital in Sydney decided to use statistics and mathematical equations to assess his role in mortality and walking speed.

Interestingly, the predicted walking speed of Death estimated in their study is virtually identical to the speed associated with average life expectancy found in a recent analysis of speed and mortality.

The researchers in Sydney analysed the walking patterns of 1,705 healthy men aged 70 and over who were participating in The Concord Health and Ageing in Men Project (CHAMP).

The men lived in the inner city and suburbs of Sydney and they were recruited from January 2005 to June 2007. The study included a high proportion of immigrants and only 50% of the participants were born in Australia, 20% were born in Italy and the other main countries of birth were Great Britain, Greece and China.

Results

The researchers assessed participants' walking speed at baseline and survival over the five-year study period.

A total of 266 deaths were observed during the follow-up. The results show that their average walking speed was 0.88 metres per second (m/s). No men with walking speeds of 1.36 m/s (3 miles or 5km per hour) or above had contact with the Grim Reaper.

The authors conclude that the results support their theory "that faster speeds are protective against mortality because fast walkers can maintain a safe distance from the Grim Reaper."

A review of studies into walking speed and life expectancy published earlier this year came to a similar conclusion. It found walking faster could be a sign that you’ll live longer, especially if you’re 75 or over.

Limitations

The Sydney study has several limitations. The authors were unable to measure the actual speed of the Grim Reaper as he was not a participant in the study, also there are accounts of people managing to trick him out of taking their life.

The study authors say future research could investigate whether a person's level of cunning enables them to walk at slow speeds while still avoiding Death.

Avoid the Grim Reaper

Fictional characters who avoid the Grim Reaper often have the benefit of invisibility cloaks, resurrection stones, and elder wands (collectively known as the Deathly Hallows) but there are other, more down to earth ways, to avoid his clutches: quit smoking, maintain a healthy weight, drink  in moderation, have a good diet, exercise and get a good night's sleep.

If all those things sound too much like new year resolutions there is one other thing you can do for your health across the festive season: socialise.  Australian researchers found elderly social butterflies were less likely to die over a 10-year period compared to people with the fewest friends. Another analysis of results from 148 studies supports the link between plentiful social connections and a long life.