In a world where doing the right thing seems to mean doing something different every week (are eggs good or bad for me today?), dispatches from the world of science can make the decision process leading to the Charge of the Light Brigade look rational.
On the subject of recommended exercise intensity and quantity, the advice du jour is, unequivocally, send three-and-fourpence, we're going to a dance. And because walking's ace-in-the-hole is its low intensity and hence accessibility, its popularity (which from a public health perspective is the same thing as efficacy) is vulnerable to the shifting winds of scientific fashion.
On the one hand, walking leads the pack; no other form of exercise can be so heartily advocated and endorsed, given the vast package of benefits accrued over short-, medium- and long-term time frames. Add to that the ease of provision (almost no additional infrastructure required), low cultural resistance and simplicity of message and walking is not far off being the perfect preventative health programme.
On the other hand, there's walking and there's walking. Some of us, it seems, are interpreting the 'proceed at your own pace' message a little too liberally. So says Paul Williams, a statistician at Lawrence Berkeley National Laboratory in California, who sampled about 7,000 male and more than 30,000 female participants from previous walking studies, representing a range of speeds from almost jogging to strolling.
Data on speed were referenced against mortality to determine which of the walkers had died in the decade or so since they had joined the survey and from what.
Nearly 2,000 of the walkers had died, and these deaths were disproportionately clustered among the slowest walkers. Those in the slowest category were about 18pc more likely to have died from any cause than those in the other three, faster categories.
The death rate was found to be higher among the slowest walkers, even if they conformed to standard exercise guidelines and expended as much energy overall as those who walked faster. Among the slowest of the slow; those whose walking pace was two-and-a-half miles per hour or less, mortality was more than 40pc higher.
Where it gets real is in Dr Williams' summary of his findings, and the bottom line implication that intensity matters if you are walking for health.
"Our results do suggest that there is a significant health benefit to pursuing a faster pace," Dr Williams said. Pushing the pace, he said, appears to bring about physiological changes that milder exercise doesn't stimulate.
One obvious reservation is that the slowest walkers in the study may have suffered from underlying conditions that predisposed them to both a reduced pace and ultimately earlier death; from which follows – and here's where it all gets a bit conundrummy – measuring your walking speed could itself provide an indicator of your health.
The really good news revealed in this study is that longevity rises with small, easily achieved increases in pace.
You don't have to be Spider-man to dodge the bullet, but you might want to consider putting a little more pep in your step.
- Conor O'Hagan is editor of the bimonthly Walking World Ireland magazine. www.walkingworldireland.com
Walk of the Week: Millennium Loop, Rathdrum, Co Wicklow
Terrain: Minor roads, forestry tracks, Mass paths, cross-country
From Rathdrum, follow the R755 towards Laragh and watch for the church on your left as you leave town; the trailhead is in its car park. Starting from the map board there, follow the purple arrow around the back and up the steps out of the grounds. Follow it for 200m to join Union Lane; turn right. Pass the school, right, to a three-way junction with a sandy lane on your right. Veer right.
Follow it for 200m to reach a gate/stile, left. Go through and veer right to Famine graveyard. Pass to right of monument and follow the trees to reach a wooden kissing gate. Then go straight across the field, following an old Mass path to reach a wooden stile which takes you into Ballygannon Woods. After 100m you reach a high fence and wooden stile. Do not cross it but turn left instead.