Saturday, February 28, 2015

Gotta Love Hills

Now those were some hills we ran in Hong Kong during the Trailwalker
I love the hills when running cross country as a kid in school. Probably because I didn't weigh that much then, so I could often accelerate up the slopes at Macritchie reservoir (yes during my time, all the schools cross country races were all held there and not Bedok reservoir). That means I could either break up the pack of runners in our group or hang in there when the going got tough.

Well, now it looks like you (the runner) should run more hills since correct practise makes perfect.

What's more, recent published evidence suggest that both up and downhill running does not seem to harm your Achilles tendon as some believe. It was previously assumed that the forces exerted on your Achilles tendon during downhill running could stretch it further leading to possible long term injury.

The Achilles tendon stretches naturally on every run. It stores elastic energy to reduce the load on your calf muscles especially. It is believed that this constant stretching leads to micro damage in the tendon, especially running downhill.

This was proved wrong after researchers (who used high speed cameras and Doppler ultrasound) proved that the Achilles maintained the same thickness during flat, up and downhill runs.
A word of caution before you attack the hills. The study was done on a group of well trained runners and this may be one of the reasons why the Achilles tendons adapted well to the different inclines.

If you are a fairly new runner and have not done many miles, do add hill running gradually to give your Achilles tendon time to adapt.


Neves KA, Johnson AW e al (2014). Does Achilles Tendon Cross Sectional Area Differ After Downhill, Level And Uphill Running In Trained Runners? J Sports Sci Med. 13: 823-828

Monday, February 23, 2015

More On Tuning In

Our Sony NWZ-W274

My wife and I share the Sony NWZ- W274. I had an older model free from Sony a few years ago. Sadly the music only comes through on the left side now so we recently bought the the W274 since we liked the fact that it did not have any dangling wires.

My wife still thinks that most of my running music is too slow. Well far too slow for her anyway.

previous post on running with music shows that while exercising with music, fast music especially can improve athletic performances.

Well, now I can say for sure even my so called "slow" music helps during running. A recently published study shows that a song's tempo may not matter as much. It's much more important that the listener finds it motivational.

In their study, the researchers had runners run three all out 5 km sessions (spread over a few weeks).

One group listened to slow motivational songs (80-100 beats per minute), while another listened to fast tunes (140-160 beats per minute). A third group ran with no music at all.The runners with music all ran faster, especially in the first 800 meters, although difference in finishing times between fast and slow music was not significantly different.

With slow music, the runners took about 26 mins for the 5 km, while those listening to fast music took 26:06 minutes. The no music group averaged 27:33 minutes. As the runners selected their own playlists, the researchers confirmed that it's more about what the song  means to the person when it comes to motivation rather than how fast the beat is.

Well, no reason to change my play list then. Just remember not to start too fast if you run with music when you race....


Bigliassi M, Leon-Dominguez U, et al (2015). How Does Music Aid 5 Km Of Running? J Str Cond Research. 29: 305-314. DOI: 10.1519/JSC.0000000000000627.

Saturday, February 14, 2015

Just How Accurate Are Those Activity Trackers?

I've seen many of my patients wearing an activity tracker and I'm sure you've seen someone sporting one on their wrists too. 

Just last week at my hydrotherapy/ deep water running session one of my patients was wearing one in the pool and she complained afterwards that she was really tired from the session but her tracker didn't seem to agree and did not track what she did! Another patient commented besides having a rather "cool" object on his wrist, he used his tracker to monitor his sleep.

Here's my patient with his"cool" Jawbone activity tracker
Well just how accurate and useful are these activity trackers?

ACE (American Council on Exercise) commissioned a study on activity trackers to measure their accuracy with regards to step count and calorie expenditure.

The following brands were tested - Nike+ Fuelband, Fitbit, Jawbone UP, Adidas MiCoach and BodyMedia Fitcore which has since been bought by Jawbone).

The subjects (aged 18 to 44) wore the trackers while walking, running on a treadmill, exercising on an elliptical machine, and performed other exercises including agility ladder drills, shooting free throws and T drills (for baseball). In order to compare, the participants also wore portable metabolic analysers and the NL-2000 pedometer, which were considered accurate and reliable by researchers.

And what did they find? Besides providing wearers with a reasonable estimate of how active they are in the daily lives , activity trackers may not be as accurate as some users believe. 

Some underestimated numbers while others overestimated them. This is true when tracking more complex activities such as playing basketball, weight lifting and cross training. Each brand of tracker has its own strengths and weaknesses. 

The "best" tracker for any given individual depends on his/ her biomechanics and what he/she wants to measure. For instance the researchers found that the Jawbone UP was the most accurate for step count while not so accurate while measuring calorie expenditure running on a treadmill.

Despite not being too accurate with tracking expenditure, the researchers found that people wearing them became 30 to 40 percent more active so maybe accuracy does not matter as much since the trackers got users to keep moving. They can also help to show  wearers when they could move more during their daily lives.

And even if your activity tracker isn’t 100 percent accurate, the researchers say you can still benefit from the feedback it provides. 
Before you go and buy yours, bear in mind that some trackers studied may not be available any more and companies do update their technology so science may not be able to keep up with technology.
Stackpool C, Porcari JP et al (2013). Accuracy Of Various Activity Trackers In Estimating Steps Taken And Energy Expenditure. Masters thesis. University of Wisconsin- La Crosse. See the ACE article here.

Sunday, February 8, 2015

How To Interpret The Straits Times Article (040215) On Excessive Running

According to Danish researchers, running excessively is as good as not exercising. After reading the write up, I wanted to put this out earlier, but with a new born child, this had to wait. Well here are my thoughts on that article reported by Straits Times on 040215 on page A8.

The study looked at mortality rates in sedentary people and runners. What was widely reported was that those who ran more (and more vigorously) died at a greater rate during the study period than those who ran less. More dramatically put, running fast is as deadly as sitting on your couch.

Firstly the same data used in this study was already published back in 2012 in another journal. Seems like no new data? Well let's just republish the same data in another journal. Even the authors are similar as the previous study with the addition of James O'Keefe who has basically been on almost every single one of those "running will kill you" articles if you look him up. The media never checks this I guess and reports it as if it was brand new.

A few other things to consider. The sample size in the study (for runners) was relatively small, while sample sizes were large in the "less active" group. (If you looked at the data, only 2 people in the strenuous exercise group died).

Categorization of the volume of jogging was also arbitrary and the participants' running volume, frequency and pace were all self reported. Moreover, causes of death were not identified in the study, meaning some deaths were due to accidents possibly and not health related. With a smaller sample size, one death could affect the results a fair bit.

Other than the Straits Times, other news sites have also "broadened" the conclusion to suggest that more ambitious (or hardcore) running is of equal health benefit to being sedentary (or sitting on your couch). They failed to report that there are also lots of published data to show the many health benefits of higher mileage runners (although there are big benefits from very little running).

My take? This one study should not change your views or approach on running. There obviously is a point when running stops being beneficial and another point which will worsen your health. However, this differs for everyone and probably not at the low levels described in the article referenced below.


Schnohr P O'Keefe JH et al (2015). Dose Of Jogging And Long Term Mortality The Copenhagen City Heart Study. J Am Coll Cardio. 65(5) : 411-419. DOI: 10. 1016/j.jacc2014.11.023.

The Straits Times article