Researchers at the University of Alberta just published some interesting data from a six-year longitudinal study looking at links between neighbourhoods, physical activity and body-mass index. Of the people who moved during the study, those who chose new neighbourhoods based in part on walkability maintained their weight (as expected), while those who chose locations based on proximity to outdoor recreation opportunities (surprisingly) gained weight.
This is by no means a perfectly controlled experiement — for example, as the researchers point out, it could be that the subjects choosing to live near outdoor recreation were doing so primarily for their kids. But it certainly fits with other data, like the fact that New York City — highly walkable but terrible for outdoor recreation opportunities — is among the thinnest cities in the U.S. (42% of people there were overweight, compared to 67% nationally, according to a 2009 study). And it underlines the point that a healthy lifestyle is more dependent on the little things you do on a daily basis, rather than the big excursions you make on weekends.
There has been a surprising amount of research into the effect of trekking poles (or hiking poles or Nordic walking poles or whatever you want to call them) in the last few years. It’s still unclear whether they raise or lower heart rate and effort — it probably depends on how you set up the experiment, and how vigorously you use your arms. But a new study that just appeared online in Medicine & Science in Sports & Exercise has an interesting finding about muscle damage that seems fairly clear-cut.
Researchers from a couple of British universities led a group of 37 people on a day-hike to the top of Mount Snowdon and back down again; half used poles and the other half didn’t. They measured all sorts of variables before, during and after, including heart rate, perceived exertion, maximal voluntary muscle contraction, soreness, etc. Both groups took the same amount of time and had (on average) the same heart rates, but the pole group reported lower perceived exertion on the way up — which agrees with some (but not all) previous studies.
The new finding in this study is that the pole-users had less leg soreness from the downhill portion of the hike (which involves damage-inducing eccentric muscle contractions) immediately after and in the days following. They also had less reduction in their maximal voluntary muscle contractions.
Now, this isn’t particularly earth-shattering. Taking the load off your legs during downhills is precisely the rationale that convinced me to try using (borrowed) poles during a hike in the Rockies a few years ago. If anything, it’s surprising that no one has tested the link between muscle soreness and poles before. So now, with a tough eight-day hike through hilly terrain coming up in exactly a week, I have to decide whether it’s worth investing in poles…
(My current strategy to avoid soreness is based on the principle that inducing DOMS once reduces the severity of the next bout. Lauren and I did a hill workout this morning — 10x30s — and for an added twisted we sprinted back down the hill after three of the intervals. Well see whether that manages to induce any protective soreness tomorrow!)
New Jockology column now posted here:
Will I get a better workout by walking, running or biking my 5K commute to work?
Most commuters strive to be as efficient as possible. To get the best workout (specifically, to burn the most calories), you’re better off being inefficient. [continue reading]
A couple of interesting points have already been raised in the comments section, including one about what “net” calories refers to. In brief:
“Net” is referring to the total calories burned while moving a kilometer MINUS the number of calories you would have burned during that time just by being alive (your “basal metabolic rate”). Otherwise walking gets credited with burning a bunch of extra calories just because it takes longer.
As a rough approximation, running burns about 50% more GROSS calories per kilometre than walking, but twice as many NET calories.
To count as exercise, walking is supposed to reach a “moderate” level of intensity, where you use about three times as much energy as you would lying on the sofa popping Cheetos. So how fast is that? According to a study by researchers at San Diego State University, it’s between 92 and 102 steps per minute for men, and between 91 and 115 steps per minute for women.
That’s assuming, of course, that you live in a home with a picket fence, a dog, and 1.4 children. Still, even if you’re not perfectly average, the researchers are comfortable drawing general conclusions:
We believe that these data support a general recommendation of walking at more than 100 steps per minute on level terrain to meet the minimum of the moderate-intensity guideline. Because health benefits can be achieved with bouts of exercise lasting at least 10 minutes, a useful starting point is to try and accumulate 1000 steps in 10 minutes, before building up to 3000 steps in 30 minutes.
So if you’ve got a pedometer (and I have the impression that pedometers are the “random branded freebie” most in vogue these days), now you know what to do with it!
I love the conclusion, in slightly stilted English, of this paper on Nordic walking (a.k.a. walking with poles):
“The work of the upper extremities seems to be a luxury effort for Nordic walkers with a proper technique.”
The study is actually fairly subtle, tracking the pole force and oxygen consumption of walkers on grass, concrete, and rubberized track. Since the walkers had to work much harder on grass even though the pole forces stay the same, the researchers conclude that it’s the legs doing all the work — the arms are just “luxury!”
This is actually something I’ve been wondering about ever since I started seeing hikers zooming up and down mountains using those ski pole thingies. I’ve even been a convert, using them for a 12-day trek in the Rockies. Now they’re ubiquitous, and — German study notwithstanding — I’m curious about their benefits. Perhaps something to look into…