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 milliters 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 mitochodria cell density, lactate threshold and your ability to oxidise 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.

References

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.

Sunday, November 27, 2016

Are There Any Benefits In Running With Zero Drop Shoes?

My wife's zero drop running shoes
Although you don't see it as much now, the minimalist type running shoes were the rage all few seasons ago. These minimalist type (and not the barefoot type) usually have a relatively low heel to toe drop. Meaning the height in the midsole and the outsole at the back of the shoe is almost level and/or no difference in height.

One proposed benefit of zero drop running shoes is that it may reduce injury. Shoes with a large drop encourage severe heel striking which can contribute to knee injuries. With zero drop shoes, it may also allow your feet to land as if you were not wearing shoes which helps to distribute impact forces.

Shoes with a high drop may also tilt you forward too much and contribute to alignment and compensatory discrepancies.

If you visit the running section of most running stores now, most midsoles of current running shoes are almost back to before when they were much thicker. But many manufacturers have retained the zero drop while offering plenty of cushioning like the Hokas and Altras.

A recent study however found that a shoe's heel to toe drop may not have have anything to do with running injuries.

The researchers studied 533 non elite runners wearing running shoes with 0, 6 or 10 millimetres (mm) drop for six months. The running shoes were 2l mm in the heel and forefoot, 21 mm in heel and 15 mm in forefoot and 24 mm in heel and 14 mm in forefoot respectively. The shoes were otherwise similar.

25 percent of the runners reported being injured during the six month study period. An injury was defined as leg or lower back pain that resulted from running and prevented planned running for at least one day.

The main finding of the study was that injury rates among the three groups were similar, regardless whether their shoes had a heel to toe drop of 0, 6 or 10 mm.

However, among the runners who ran more frequently, those in the 0 or 6 mm drop shoes had a higher injury rate than the frequent runners with a 10 mm drop.

The researchers suggested that that this may be due to the runners transitioning to fast from their regular running shoes to zero drop shoes leading to increased injury rates as 78 percent of the runners recruited in the study hadn't run in zero drop shoes before.

I remember when I was racing cross country races as a kid we used to train in heavier cushioning shoes and then switched to racing flats for the race. It was very common to have sore calves after the first few races of the season as I've not done enough running in the racing shoes (which had lower drop than the training shoes). Yes, racing flats back then were very similar to the zero drop shoes now.

It was more apparent (sore calves) switching to racing spikes for the track training and track meets when cross country season ended and I raced in track events.

As I always tell my patients, their running technique is much more important than their running shoes. Be sure to rotate your running shoes to minimise injuries too.

Reference

Malisoux L, Chambon N et al (2016). Influence Of The Heel-to-Toe Drop Of Standard Cushioned Running Shoes On Injury Risk In Leisure-time Runners. A Randomized Controlled Trial With 6-month Follow-up. AJSM. 44(11): 2933-2940. DOI: 10.1177/0363546516654690.


Now, this is what I'll call a racing flat

Monday, November 21, 2016

Even Physiotherapists Get Injured

Message from my colleague
Here's another patient case study, except it's not a patient in our clinic but one of my colleagues.

She came to work last Monday (14/11/16) complaining of extreme soreness and and pain in her right hamstring. She had played a soccer match on Sunday and she messaged me on Sunday night saying she can't straighten her knee and that her hamstrings feel super tight and painful.

Walking and most activities of daily living weren't a problem. Could still treat patients at work. Definitely too sore to run. Light cycling on stationary bike with light resistance made it more bearable.

Now my colleague is a 24 years young and active physio and a devastatingly effective striker in her junior college days. Her school beat my alma mater's team 10-1 in the semi finals of the tournament seven years ago and she bagged a hat trick in that match.

Earlier in the year when I introduced her to a physical education teacher from the beaten school, he instantly remembered the trashing and was in awe of her. Still famous seven years after that game.

Anyway, I treated my colleague last Monday (14/11/16), made sure her injury was only in her hamstrings and not referring from her lumbar spine. She was very sore in her right Adductor Magnus and Semitendinosus muscle.

We both agreed it was more a stretching type hamstring injury than a high speed type running injury to her hamstrings.

On Tuesday (15/11/16) she was only slightly better and I got another colleague to treat her as I was working that day at Physio Solutions.

Over the next couple of days we left it alone and this was what showed up in her hamstrings on Friday 18/11/16.
Check out the bleeding 
She had a minor hamstring tear! That's why she was feeling so sore and painful initially. Well, we all learn from our experiences. We would never have guessed it was a minor tear if this didn't show up.

Taped it to reduce the swelling and I also facilitated her Semitendinosus muscle with Kinesio Tape as I felt it would help her walk better. She said she had to remove the facilitated bit as it made her sore the next day. Yikes.

Wow, six days after the injury, it was still acute! And we thought that the inflammatory phase of an injury usually lasted only 48 hours. Certainly not in her case. That's the reason why I'm documenting her case, so I will always remember this.

Her leg after we removed the tape today (21/11/16).
Much improved
I inhibited Semitendiosus muscle instead today and she said that made it better.

Lesson learnt and note to self - acute inflammatory phase can last longer than 48 hours post injury.

Close up of her hamstrings today (21/11/16)

Sunday, November 20, 2016

Patient With "Shoulder Tendinitis" Not Better After Medication

Can you guess what's wrong with my patient's shoulder?
Just by looking at the picture above, can you guess which shoulder was giving my patient problems? I also showed the picture to some of my staff and asked them "what can you see from this picture?"

Alright, for those who can't tell, here are some more clues. My patient came in with some neck pain and a very uncomfortable shoulder. He had seen his family doctor who told him he had tendinitis in his shoulder and gave him some NSAIDS (non steroidal anti inflammatory drugs).

However he did not get much better with the medication. He still had some neck discomfort and couldn't raise his arm above shoulder height. Lying on his affected side made his shoulder worse and he could only sleep supine.

At first I too thought the shoulder pain was referred from his neck. He mentioned that there was slight tingling sensation in his fingers occasionally too (which was why I thought the problem was coming from his neck). However I changed my mind after seeing he had trouble even lifting his arm sideways above shoulder height.

I told him that he probably had a tear in his L Supraspinatus muscle. If you look at the picture above carefully, you will see a hollowing above his left shoulder blade. There is also wasting in the muscle (or muscle atrophy) around the part where his neck on the left connects to his shoulder.

I was told later after an ultrasound scan that he had a full thickness tear in his left Supraspinatus muscle with retraction of the tendon! The doctor referred him for an MRI and said he may need surgery to repair the retracted tendon.

By the way, scientists have assessed biopsies from both people and animals with supposed tendinitis and found very few signs of inflammation in the tendons.

NSAIDs are commonly prescribed to reduce pain and inflammation of tendinitis. So if there is no inflammation, the medication is not going to help.

So the word tendinitis with the suffix "itis" means inflammation is misnamed since the condition has little or no inflammation. Researchers prefer the term "tendinopathy" meaning damaged or degenerating tendon.


Reference

Warden SJ (2009). Prophylactic Misuse And Recommended Use Of Non-steroidal Anti-inflammatory Drugs By Athletes. BJSM. 43(8): 548-549. DOI: 10.1136/bjsm.2008.056697.

Sunday, November 13, 2016

Physio And Sports Solutions Lunch 2016

Both our clinics came together to have lunch today at the Straits Kitchen restaurant in Hyatt hotel today.

This is our biggest turn out ever and a big thank you to all our staff and their familes/ loved ones who came. For those who were not feeling well or were travelling, well, here's what you missed.

Waiting for the start
We had quite a few tables
Guess who ate this for first round?
Guess who's the best eater?
Trying to fit everyone in the picture

Sunday, November 6, 2016

Hands-free Mobile Phone Drivers Roughly The Same As Drunk Drivers


Posed picture of me using mobile phone while driving
I'm sure you've seen lots of drivers driving and using their phone at the same time. I saw three drivers using their phones while standing at the back door of our clinic this morning, According to Singapore Traffic Police figures, at least eight drivers were caught using their mobile devices behind the wheel last year. Hopefully, you're not one of them.

Here's an article I found by a group of researchers comparing the effects of a variety of mobile phone usage conditions to different levels of alcohol intoxication on driving performance and vigilance.

Each participant had to complete a simulated driving task on two days, separated by a week's break. Driving performance was assessed by variables including time spent speeding, braking reaction time, time driving in target speed range, lateral lane position and speed deviation etc

On the mobile phone day, the participants performed the simulated driving task under the following four conditions. No phone usage, a hands free conversation, a hands free but cognitively demanding conversation and texting.

On the alcohol day, the participants performed the simulated driving task at four different blood alcohol concentration levels (BAC), 0.00. 0.04, 0.07 and 0.1.

Here's what they found. Under BAC 0.7 and 0.1 alcohol conditions, the participants spent less time in the target speed range, more time speeding and took longer to brake than in the 0.00 condition.

While using their mobile phones, participants took longer to brake in the hands free conversation, cognitively demanding hands free conversation and while texting. They also spent less time in the target speed range and more time speeding in the cognitively demanding hands free conversation and while texting.

When comparing both conditions, the hands free conversation was comparable to the legally permissible BAC level (0.04). The cognitively demanding and texting conversations were similar to the BAC 0.07 to 0.1 results.

According to the conclusion by the authors, simple hands free conversations while driving may not represent a significant driving risk (comparable to legally permissible BAC levels). Cognitively demanding hands free conversation and especially texting while driving represent significant risks to driving i.e. similar to when they were drunk!

In Singapore, it is currently illegal for drivers to hold any type of mobile device while driving. As long as you're holding it while the vehicle is moving you can be charged. Previously, you could not call or text on a mobile phone.

However, it is not illegal to use a mobile device if it is mounted on a holder or a dashboard. Wearable technology such as Google Glass or the Apple watch is not mentioned though.

So be safe while you're out on the roads (especially if you're cycling).

Reference

Leung S, Croft RJ et al (2012). A Comparison Of The Effect Of Mobile Phone Use And Alcohol Consumption On Drving Simulation Performance. Traffic Inj Prev. 13(6): 566-574. DOI: 10.1080/15389588.2012.683118.

Riding with one finger and giving cyclists a bad name
*Picture by Comrade King from Flickr.

Monday, October 24, 2016

Arches And Orthotics

Picture from article Scientific Reports
I've often been asked by my patients about whether they need orthotics. The following article I read will explain some of the research behind orthotics on how they can affect your running rather than just my opinion.

Each time we land on our arches when we run, energy is stored in our arches. This is free energy that doesn't require anything to activate. The researchers wanted to measure wanted to find out specifically how much energy is lost if they restricted the arch with orthotics.
Orthotic that was used
The researchers made two types of custom orthotics. One completely blocked the arch from collapsing while the other allowed the arch to compress (or collapse) halfway. Only runners who did not use orthotics were recruited for their study. The runners ran on a force plate treadmill. The shoes had sensors inside which measured energy expenditure.

In order to have a baseline measurement, the runners ran in just the shoes (that were similar for all runners, pictured below) first followed by the same shoes at the same speed while testing the home made orthotics.

Picture from Scientific Reports

The runners tested the orthotics while walking as well as running.While walking, there was virtually no difference in energy expenditure. However, while running significant energy loss occurred.

In the orthotics that blocked all compression, researchers measured an energy cost of six percent (or less efficient by six percent) while the orthotics that allowed for 50 percent compression lost four percent.

Before you throw away your orthotics (if you're wearing them) the authors suggested don't throw them out yet as many runners get custom made insoles to prevent injury. They felt this is more important than saving energy without the orthotics. In fact the authors were very diplomatic and said that "We don't want to say orthotics are good or bad."

Likewise, if you are considering wearing orthotics (but may not need them), then maybe you shouldn't especially if you wanna run faster.

Reference

Stearne SM, McDonald KA et al (2016). The Foot's Arch And The Energetics Of Human Locomotion. Scientic Reports 6, Article number: 19403. DOI: 10.1038/srep1940.