Friday, December 23, 2016

If Only You Know The Power Of Sleep ....

The power of sleep
While I was still working at the Singapore Sports Council or SSC (now known as the Singapore Institute of Sport or SSI) I used to travel a lot with the Singapore badminton players while they were competing or training overseas.

And no matter where the badminton players were training or competing, their normal routine would be training in the morning, break for lunch and there would always be a nap after lunch before training again. Even our national table tennis players took daily naps when they were not out buying eggs (okay I'm just kidding). No disrespect meant!

Why am I writing about sleep here? You and I know that a lack of sleep can lead to negative consequences. It can affect your mood, cognitive function and physical performance. Few studies though have looked at the opposite - the effects that sleep extension can have on performance.

The American National Sleep Foundation recommends 7-9 hours of sleep a night for adults for general health and well being. But a study on Stanford basketball players by researchers Cheri Mah and colleagues showed that with 5-7 weeks of sleep extension, i.e. going to bed earlier and waking later, subjects had improved basketball performance, reaction time and running speed.

The researchers concluded that "extended sleep beyond one's habitual nightly sleep likely contributes to improved athletic performance."

As it is, most of us will find it difficult (myself included) to find more time to sleep. Our smart phones, the iPad, Netflix etc are big distractions. Yes, I have to stay up writing this so you can read it. Well, I'm not racing anymore.

Many of you will focus on improving your performance by training harder and smarter, but those improvements become smaller and more difficult to obtain after a while. Your fellow competitors will likely swim/ bike/ run similar intervals in addition to hitting the weights room etc. It all comes to to all the fine details. Some of these small gains (like sleep extension) are found outside of aerobic and interval training.

It's probably easier to change your bedtime to get more sleep by gradually going to sleep earlier. Try to go 15 to 30 minutes earlier each night to find a good time for yourself.

Sleeping in never happens for my wife and I, our boys are up by 6 am or earlier most mornings. If you can sleep in good for you.

I remember attending a meeting prior to the 2004 Athens Olympics where the then Director of High Performance, SSC was questioning the then CEO of Singapore Badminton Association (SBA) why the Singapore badminton players needed naps when they could be working part time or studying in between training as what many of the elite athletes at the Australian Institute of Sports do.

Then CEO of SBA's reply was if it (naps) has the potential to impact performance in a positive manner, then we try to take care of it.

In the picture below you see me more excited than Ronald Susilo after he defeated Lin Dan in the 1st round at the 2004 Athens Olympics.

That's how we should help our athletes.


Mah CD, Mah KE et al (2011). The Effects Of Sleep Extension On The Athletic Performance Of Collegiate Basketball Players. Sleep. 34(7): 943-950. DOI: 10.5665/sleep.1132

I really like this picture I took from a Star Wars book - Goodnight Darth Vader which I bought for my son by Jeffrey Brown.

Sunday, December 18, 2016

Which Calf Is Bigger?

Notice any difference in the picture above? If you look closely, you'll notice that the left calf is slightly bigger than the right. Upon palpation my patient's left calf does feel more "meaty" compared to his right.

This is surprising as my patient says that his right leg is his dominant leg. Usually the dominant leg is bigger and stronger than the non dominant leg.

Now, this patient, who is an ultra marathoner came in to see me yesterday after a 35 km training run in the morning. He said that his right calf muscle often cramps after about 35 km.

Even after an easy run, his right calf and hamstrings often feel more tired and fatigued compared to his left. He also felt that it required more effort to bend his left knee compared to his right.

My patient also does not have any numbness, pins and needles down his right leg or other neurological signs. After checking his back as well, I explained to my patient that the reason for his muscle cramping in his right calf muscle is simply due to muscular fatigue.

Since his left calf is bigger, it will also be stronger than his right calf. This means that after running a certain distance his right calf will work harder than the left calf and will fatigue faster too.

I explained that muscle cramping is not due to sodium (or salt) loss, dehydration, electrolyte or fluid loss. I've explained this in a bit more detail before in another post, have a read here please if you're keen.

We then discussed how he could do some isolated (right) leg training to make his right calf stronger to avoid cramping eventually.

Here in his case, size does matter.


Schwellnus MP, Nichol J, Laubscher T and Noakes T. (2004). Serum Electrolytes Concentrations And Hydration Status Are Not Associated With Exercise Associated Muscle Cramping (EAMC) In Distance Runners. BJSM. 38: 488-492. DOI: 10.1136/bjsm.2003.007021.

Saturday, December 10, 2016

Last Floss Band Course ....

... for this year.

I was informed earlier by Jane today that this is the 6th Floss Band course I've done for the year. Wow, I haven't really been keeping count and didn't realise we've done so many thus far. This I must say though, the year has really flown by. It's 3 weeks to the end of the year!

Well, one thing remained constant. We had a full house again today. There were lots of physiotherapists (from SGH and Khoo Teck Puat Hospital) and many physiotherapy students too among those who signed up. I always enjoy having fellow physiotherapists around to share and bounce ideas.
Getting to know the participants
Asking Jensen to demo for a change
Bert having a go 
I'm the winner!
 Jacqui (Her Lift's gym) and her dislocated shoulder ....
Jane, Danny, Amy and Jerome came really early for lunch first and then got everything ready when I was still seeing patients. Really appreciate their help in setting up the place and also packing up when we were done. Please contact them at Sanctband Singapore for the next Floss Band course.

A big thank you to everyone who came too, hope everyone learnt something useful and can implement in your own area of work.

It was nice seeing Ang Hong again today too. She was my relief form teacher and taught me Biology when I was 15 years young when my form teacher went on medical leave for a few months. She was also one of the first few female triathletes I knew back then.

And yes, this is the last Floss Band course for this year, but there will be more next year. Stay tuned.

*Thanks to Jane Fong and Danny Ho for the pictures.

Sunday, December 4, 2016

How Quickly Do You Lose Fitness When You Stop Training?

Picture of Singapore Stan Chart marathon by RunSociety from Flickr
Well, many of you've just done your last race of the season. Yes, after the Standard Chartered Singapore Marathon 2016 this morning it's off season time at last.

Now it's time to take some much needed rest, both physically and mentally and not worry about training for a while.

The most common question and worst fear among my patients who run (or race triathlons) is how quickly do they go out of shape if they stop running (or training).

Ever wondered how long before detraining kicks in? Well, just as you don't become a fast runner overnight, you don't lose your fitness that quickly too. Nothing goes up in a straight line, there'll be some peaks and valleys. Likewise you don't lose your fitness overnight too.

Okay, first the good news. Research on detraining or how quickly you go out of shape shows that those who are less well-trained have less to lose. This make sense considering the elite athletes have further to fall.

Elite athletes can lose up to half of their aerobic fitness within the first 12-21 days of not training. They can then lose half of their remaining fitness in the next 12-21 days and so on. The bad news, those who've trained for a few months have a slower decline, but lost all fitness within 4 weeks.

Most studies suggest that an elite athlete's VO2 max levels drop 7 percent if they stop training for 12-21 days. They can lose another 9 percent from days 21-84.

One major reason for the quick fitness decline is the loss of blood volume. In the first 12-21 days that you stop training, you can lose up to 500 milliliters of blood. It's a simple supply and demand situation. When you stop training, you take away the demand.

The body loses the ability to bring oxygen to the muscles and you also have less fluid available for sweating (which cools the body).

The good news is with retraining, you can regain blood volume in a week although it takes a while for your red blood cells to grow again.

Other than blood volume, your mitochondria cell density, lactate threshold and your ability to oxidize fat stores all deteriorate.

Researchers have found it difficult however to measure time to regain your fitness. A common suggestion is that for every week lost, it takes two weeks to regain that previous level. The reason for this all those functional capabilities mentioned above.

When I was still racing, I used to take two weeks off at the end of the season. Yes, two weeks of no swimming, running, cycling and weight training. This allowed me to recuperate both physically, recharge mentally and also to spend time with my family, loved ones and friends. And when its time to train again, I'd be raring to go.

Do bear in mind that not all systems in your body detrain or retrain equally. Do consider your age. Runners in their 20's can resume training as though they never took time off. Older runners will take longer. 

Strength gains (from weight training) are not lost as quickly as aerobic (or cardiovascular fitness) and it usually takes 4 weeks before you start to lose peak muscle strength and maybe that will be another article later on.

So congrats and well done to those of you who ran this morning and make sure you take that well deserved time off.


Coyle EF, Hemmert MK et al (1986). Effects Of Detraining On Cardiovascular Responses To Exercise: Role Of Blood Volume. JAP. 60(1): 95-99.

Joyner MJ and Coyle EF (2008). Endurance Exercise Performances: The Physiology Of Champions. J Physiol. 586(1): 35-44. DOI: 10.1113/j.physiol.2007.143834.