Why Your Doctor May Not Give The Best Nutritional Advice

Picture by DES Daughter from Flickr

While doing some research on the Mediterranean-style diet (that will probably be another post), I came across and read with interest an article in the Chicago Tribune. Of the many, many thousand hours that doctors spend training to become doctors, only 19 of those are devoted to studying nutrition.

Not surprising then that a study from the Journal of American College of Nutrition shows that 14 % of internal medicine interns feel they can talk adequately to their patients although 94 % feel it's their responsibility to do so.

Now don't get me wrong, I have nothing against doctors nor do I claim to be an expert in nutrition. How can I be since I love eating chips and drinking Coke (although I very seldom indulge now after my accident).

For most people I know, doctors are their gatekeepers to health information. They know doctors are educated in their profession and are generally trustworthy. It seems then that a doctor's advice must be reliable. I guess some people think curing diseases/ illnesses" is the same as preventing diseases/ illnesses.

Let me be clear here though, my opinion is that this is a failing of the medical educational system and not the fault of our doctors.

One of medicine's basic tenets: "First do no harm." So doctors must make sure any treatment must not make a patients's condition worse. For nutrition, this usually translates into standard dietary advice.

Let me give you an example. A doctor is faced with the choice of giving a recommendation that's in line with the status quo such as limiting sodium (or salt) intake, or go against the norm by saying that you don't have to worry about salt intake.The doctor will usually avoid controversy and just say limit salt intake.

Also among other obstacles? In the same Chicago Tribune article, it is suggested that "many physicians are overweight themselves and may feel uncomfortable talking about healthy diet and physical activity when they themselves struggle with similar issues."

When faced with conflicting information, most of us deal with it in different ways. Some like my wife (bless her) are self-learners, they read voraciously until they can navigate through the noise. Most people may just default to someone they trust to tell them what to do.

After You Donate Blood .....

..... you can race again in about 2 weeks, according to published research.

Picture by Howard Lake from Flickr

That's about how long it takes before you regain your pre donation levels.

A group of regular blood donor runners with normal blood levels did a 3 kilometre treadmill time trial in this particular study. The time trial was repeated 2, 7, 14 and 28 days after donating blood. Their haemoglobin (Hb) levels were measured on those sessions. Hb is a protein in the red blood cells that ferries oxygen from your lungs to the rest of your body.

3 days after giving blood, the runners were about 5.4 % slower before giving blood. 2 weeks after giving blood, the runners had regained the pre donation speed although Hb levels were still 5.9 % lower.

28 days later, the runners ran as quick as pre donation, but Hb levels were still lower (even though they were higher than after 2 weeks).
This study measured 3 kilometre time trial performance, bear in mind that fif you want to race well for longer events, you may take a longer time to regain your pre donation levels.

The researchers suggest that you can resume training the next day after giving blood, but wait at least 2 weeks before you rave again.

Reference

Zieglar, AK, Grand, J et al (2014). Time Course For The Recovery Of Physical Performance, Blood Hemoglobin, And Ferritin Content After Blood Donation. Transfusion. DOI: 10.11111./trt.12926.

Eating Like The Caveman? ST 050315

Our Sports Solutions blog has a much bigger head start on the Straits Times this time round with their article on "Eat Like A Caveman" in today's Straits Times in the Mind Your Body section on pages 8-9.

I first wrote about this caveman diet (or Paleolithic diet) way back in 2009 and a more detailed follow up article after that. Clink on the links to have a read.

Like I said, more reason to read our blogs.

You Saw The Coffee Article On Our Other Blog First

We got a slight head start on Straits Times on informing you about the benefits on drinking coffee published in our Physio Solutions blog. More reason to read our blogs.

The Straits Times article is on page A6 under "Top of the news".

Go take a look.

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.

Reference

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

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.

A 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....

Reference

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.

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.

Reference

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.