Sunday, November 30, 2014

What Happens On Your First Run In Minimalist Running Shoes

Nike Free 3.0 (left) and 4.0 (right)
Runners hate getting injured since they usually can't run while nursing an injury. To minimise injury, you can vary the impact forces by running on different surfaces, running at different speeds and running on different terrain. I wrote previously that rotating your running shoes can help prevent injury as it loads bones and soft tissue differently.

Vibrams have been taken to task for advertising that wearing their shoes can help you change your running gait and thus prevent injuries.

Now I have good news for runners wanting to try minimalist running shoes. Another study has shown that switching from conventional running shoes to Nike Frees does not change your running gait, which is great for those of you thinking of transitioning to minimalist running shoes provided your running technique is correct.

Researchers had runners who were used to running in conventional running shoes do three 10 minute runs. First 10 minutes in their normal shoes, then in Nike Free 3.0, and in their normal shoes again.

The researchers expected the runners would change their gait while running in the Nike Frees as they were unfamiliar with the shoes. (This is thought to increase injury risk as you need to get used to a different shoe).

The researchers were surprised to report that in trained runners, there was no change in lower limb variability while wearing minimalist shoes for the first time. It was similar when the runners switched back to their regular shoes.

My own personal take on this? As written previously, the Nike Free's are probably on the conservative end of minimalist running shoes (as compared to say Vibrams) and provide cushioning close to traditional running shoes. It may be different for minimalist shoes that are more minimalist.

Now while I'm writing on Nike Free's, remember I received 3 pairs of Nike Free's earlier this year? Well, I guess it's not too late for me to write a little on how the shoes feel since I've logged some decent miles in them.

Since late May this year I've been working a couple of half days at Physio Solutions. I usually try to run home after I'm done seeing patients there.

Well, I worked there 3 half days this week, which means I ran home 3x this week!! When I first started running home, I ran mostly in my 3.0's. Now I prefer the 4.0, mainly because the 3.0 seems to run a bit on the short length wise. Probably half a size smaller. My suspicions were confirmed when I put my 3.0's and 4.0's together. Though both were listed as size 7, the 3.0's were a tiny bit smaller.

Slight difference in length even though both same size
Width wise the 3.0's were pretty snug. Again I found it easier to put on and take off the 4.0's compared to the 3.0's. The 3.0's had a more "sock-like" feel compared to the 4.0's. Both have very soft midsoles. I sometimes try to cough deliberately when I'm running to pass someone as quite a few people who don't hear me have been startled when I run pass them.

As for my 5.0's,I've not run in them yet, just worn them for walking around.


Frank NS et al (2013). Lower Limb Kinematic Variability Associated With Minimal Footwear During Running. Footwear Sci. 5(3): 171-177.  DOI: 10.1080/1942480.2013.797505.

*Thanks to Andrew Kwong again for my 3 pair's of Nike Free's, to Andrea Goh for bringing them and Ernest Rodrigues and Duane Wee for previous Nike Free's.

My previous 5.0 all worn
The "pull-tab" makes it easier to wear

Sunday, November 23, 2014

Running Does Not Wear Out Your Knees

Picture by Cameron Drake on work done by Dr Noah Weiss
How many of you have had friends tell you that you'd better stop running as running causes your knee joints to wear out. I've had my fair share too.

Well, now you can tell all the naysayers that running (at any age) does not increase your risk of osteoarthritis (or wearing out of your joints), in fact they may even prevent the condition. This information was presented at the annual meeting of the American College of Rheumatology.

Researchers did a long term study on 2,683 subjects at four stages of their life : 12-18, 19-34, 35-49 and 50 and older. They were classified as a runner at that stage if they listed running as one of their three main activities.

X-rays of the knees were collected as well as subjects' reports of symptomatic pain. The knee x-rays were repeated again two years later. Analyses showed that 22.8 % of the participants who were runners had need osteoarthritis compared to 29.8 % who had never been a runner. And get this, average age of the participants was 64.7 years.

The authors concluded that "non-elite running at any time in life does not appear detrimental and may be protective" in regards to developing knee osteoarthritis.


Sunday, November 16, 2014

Air Quality In Your Gym

Last week I wrote about the potential pitfalls of exercising in the haze, but we didn't get any haze thankfully due to all the rain from the northeast monsoon. Guess it worked out pretty well then.

With all that rain, some of you may be tempted to give up your exercise plans or shift your workouts indoors into gyms. All good so far right as you expect there won't be any pollution indoors.  I've written that exercising in polluted air is undesirable and can damage your brain and lungs. But guess what, the air in your gym may not be that clean either.

In the article referenced below, researchers monitored 11 gyms (in Lisbon, Portugal) to measure pollutants during the evening/ late afternoon hours since the gyms will be packed at that time.

Subsequently, additional monitors were placed in three gyms to get more detailed readings. These monitors measured air quality throughout the building and throughout the day.

What the researchers found were alarming.  Levels of carbon dioxide, airborne dust and formaldehyde exceeded national levels.

High concentrations of dust and chemicals like formaldehyde can contribute to asthma and other respiratory problems. Almost all the gyms in the study had levels of these substances that significantly exceeded European standards for healthy indoor air.

The levels of carbon dioxide were especially high during evening aerobics classes. Many people were packed into smaller studios/ rooms stirring up dust, fumes and were panting heavily, producing carbon dioxide with every breath. High concentrations of carbon dioxide can contribute to fatigue and cognitive fogginess, not desirable at all in a high intensity aerobics class.

Elevated levels of carbon dioxide may also indicate a building that is poorly ventilated especially if levels remain elevated (they did in this study). The researchers suggest gym goers sniff the air for chemical smells and stale air (as it differs from unwashed gym clothes odour) and consider talking to the gym manager whether the building has undergone a indoor air quality assessment.

As far as I know, no one formally monitors air quality in our gyms here in Singapore, so gym goers be warned.


Ramos CA et al (2014). Exposure To Indoor Air Pollutants During Physical Activity In Fitness Centers. Building and Environment. 82: 349-360.

Friday, November 7, 2014

Is Exercising In The Haze Worth The Risk?

Hazy Singapore - Picture kindly allowed by Hak Liang from Flickr
I was away for the past 2 weeks and my parents when picking us up from the airport mentioned that the haze was bad over the weekend. However it's been raining a fair bit these past few days, so obviously no sign of any haze that has on occasion engulfed our skies in recent times.

When we exercise outdoors, we obviously breathe deeper and more frequently and hence take in more air pollution. A question often asked in times when the haze is bad is whether you should stop exercising outdoors to minimize exposure to the haze/ pollution.

The best known case I recall about an athlete worried about his health due to air pollution was Haile Gebreselasssie. He was then the world record holder in the marathon, but decided not to race the marathon at the Beijing 2008 Olympics due to concerns about the air quality as he suffered from asthma.

Now, there is much documented proof that regular exercise makes you smarter (a neurotropin - brain-deprived neurotropic factor, BDNF plays a key role).

There is also evidence that exposure to air pollution damages your brain and lungs.

Research suggests that while there may be benefits while exercising in polluted air, some of the positive cognitive effects of exercise may be lost. Consider the following two experiments.

A group of cyclists performed 2 identical cycling tests. One was done in a lab where the air was "clean" while the other test was done riding along a busy road with moderate pollution.

Result? Cylists' BDNF levels rose while performing the test in the lab. Along the busy road, levels did not.

In another study, subjects participated in a 12-week training program. One group trained in a rural environment, the other group an urban area. End result showed that participants in the rural environment performed better in tests involving working memory and problem solving.

The authors suggest exercising in a "green environment", avoiding close proximity to traffic, rush hour traffic, and polluted urban environments. Pollution tends to be less in rainy and windy conditions too.

So there you have it, some suggestions that the benefits you gain from exercise may be negated if the exercise was done in a polluted environment.


Bos I, De Boever P et al (2014). Physical Activity, Air Pollution And the Brain. Sports Medicine. 44(11): 1505-1518.