Sunday, September 20, 2020

Are You Choosing Running Shoes Based On Comfort?

Don't we all love shoes that are comfortable? Especially when it comes to our 
running shoes. As runners, we all love that ahhhh sensation of our first steps in an exceptionally soft and comfy shoe. I couldn't believe how soft an Adidas NMD (not really running shoe though) felt when I first slipped it on. 

A more comfortable (or cushioned) shoe is usually preferred by new runners or for runners who are prone to injury and want extra protection and support.

The shoe companies know that subjective comfort is an essential factor in sport shoe development since this definitely helps them sell shoes. This comfort paradigm is based on an assumption that perceived comfort will lead to a path of least resistance (while running) and potentially reduce injury and improve running economy. (Luo et al 2009; Mundermann et al, 2001).

We've definitely been sold on advertisements selling us the softest, bounciest and energy return shoes that propel us forward and saves us energy and prevent injuries.

One study showed reduced oxygen consumption levels during running at submaximal speed while running in shoes that were rated subjectively as most comfortable (Luo et al, 2009). This may support the fact that running economy improves due to reduction of muscle activation (which decreases oxygen consumption or metabolic demand). 

Another study on military personnel showed some evidence supporting the use of comfortable shoe inserts (or orthotics) reduced injury rates of the foot, ankle, hip, knee and lower back compared to a vontrol group.  However, two studies are not credible enough to know what actually helps and what are the mechanisms of reduction in oxygen consumption and preventing injuries. (Both studies count Professor of Biomechanics Benno Nigg, known for his work of running shoes as one of the authors).

In this latest paper I read, the authors aimed to investigate how shoes of differing comfort affects differences in oxygen demand along with potential mechanisms associated with injury risk

Fifteen male runners who ran at least 20 km per week with treadmill experience were recruited for the study. Testing includes an incremental lactate threshold test, a comfort assessment and treadmill running trials for biomechanical and physiological assessments. 

The researchers did not find any decrease in oxygen consumption in the most preferred shoe. Potential biomechanical contributors to changes in oxygen consumption (or metabolic demand) showed some differences in stride rate between the most preferred and least preferred shoe. Personally, it was interesting for me to note that stride frequency was actually lower in the most preferred (or comfortable) shoe compared to the least preferred (or least comfortable).

Based on the findings of this study, previous suggestions (derived from two other studies) regarding positive effects of enhanced footwear comfort during running cannot be supported. Neither on running economy nor on preventing injuries.

Should we then choose our running shoes based on comfort alone? This study suggest maybe not since the most comfortable shoes were not better or worse off with regards to oxygen consumption and not enough data to show any real change on injury risk.

Comfort is just one of many factors when we choose running shoes (compared to the more common foot type option like overpronators, supinators etc). Of course I definitely would not suggest running in shoes that are uncomfortable. 

I'm also feeling appalled that only 15 male runners (and no female  runners) were selected for the study. Remember I write previously how difficult it is to recruit runners to participate in a running research.

Athletes will want shoes that give them absolute efficiency that helps that run faster while your average runner would want the least discomfort while running to get fit.  

Of course there are some runners that will choose based on colour! *facepalm*


Lindorfer J, Kroll J and Schwameder H (2019). Does Enhanced Footwear Comfort Affect Oxygen And Running Biomechanics? Eur J Sport Sci. 20(4): 468-476. DOI : 10.1080/17461391.2019.164028

Luo, G, Stergiou P et al (2009). Improved Footwear Comfort Reduces Oxygen Consumption During Running. Footwear Sci. 1(1): 25-29. DOI: 10.1080/194242809002993001

Mundermann A, Stefanyshyn DJ and Nigg BM et al (2001). Relationship Between Footwear Comfort of Shoe Inserts and Anthropometric And Sensory Factors. Med Sci Sport Ex. 33(11): 1939-1945. DOI: 10.1097/00005768-200111000-00021.

Notes on the shoes in this study provided by Adidas

Five different shoes based on criteria previously reported in another study (Luo et al, 2009) were provided for this study. The shoe conditions showed variations in total mass (80 grams), heel lift (3.7mm), forefoot cushioning, rearfoot cushioning forefoot bending and rearfoot bending. The shoes in this study includes a standard neutral running shoe, shoes equipped with non standardized features like carbon fiber plates for increased longitudinal bending stiffness, exaggerated arch support and a cross training shoe.

One interesting point was that the researchers glued lead to the heel counters of the shoes that were lighter (since shoe mass influences oxygen consumption by about 1% per 100 grams of additional mass).

Sunday, September 13, 2020

Physical Activity Decreases Your Risk Of Colorectal Cancer

Group ride on 090219 - definitely miss those rides
I was very active in primary school. Other than swimming occasionally and playing police and thief (running), I also played football, basketball, table tennis and badminton. It was only in secondary school that I started to be more serious with cross country running and athletics.

How about you? Try to recall what you were doing as a teenager. A recent study suggest that how active you were back then and and how you've maintained it till now is important when gauging your risk of colorectal cancer.

Physical activity during adolescence helps lower risk of colorectal cancer. If you have been able to continue daily moderate physical exercise well into adulthood, the results are even better.

The study showed that those who did at least an hour of physical activity daily from 12 to 22 years had a reduced risk of adenoma (polyps or a benign tumor formed from glandular tissue) by 7 percent compared to those who were less active. (Polys are considered a precursor of colorectal cancer).

Those who started physical activity as adults reduced risk by 9 percent. However, those are were active as teens and continued being active for at least an hour as adults reduced their adenoma risk by 24 percent!

The researchers analysed the data of 28,250 female subjects aged 25 to 42. Physical activity, nutrition, hormones were among some of the data studied.

The researchers suggest that being physically active reduces the risk of colorectal cancer since it helps weight management and control and thereby affects insulin resistance and inflammation as they are involved in promotion and progression of cancer.

I would be very interested if the researchers measured how intense or hard the physical activities were. And how often were these higher intensity sessions and whether they made any difference.

However, this study did not analyse that. The authors did mentioned that previous studies have shown that moderate to vigorous activities were associated with lower bowel, breast and endometrium cancers.

Take home message is that there is a cumulative effect of physical activity as we grow older. Even if you have been inactive as a child, it is not too late to start now. And the longer you maintain that physical activity, the better off you'll be.


Rezande L, Lee DH, Keum N et al, (2019). Physical Activity During Adolescence And Risk Of Colorectal Adenoma Later In Life: Results From The Nurses' Health Study II. Br J Cancer. 121: 86-94. DOI: 10.1038/s41416-019-0454-1.

Picture above taken yesterday by Dennis. I still try to be as active as possible daily with at least one complete rest day a week.

You should too.

Sunday, September 6, 2020

What is More Helpful Than Electrolytes In Preventing Muscle Cramps?

I don't believe this. Many athletes still do not know what causes muscle cramps. In a survey of 344 endurance athletes published last year, 75 percent believed that taking extra sodium would help prevent their muscles cramping (McCubbin et al, 2019).

The usual and common theories for muscle cramps are loss of electrolytes (sodium, potassium and magnesium) and dehydration (fluid). Suggestions to combat cramps are to eat more bananas, take more salt/ sodiummagnesium supplementation, drink Gatorade etc. None of which will really help.

Having written on muscle cramps a few times, I'm most interested when new research suggests alternative ways to beat muscle cramping.

The researchers (Martinez-Navarro et al, 2020) recruited 98 runners running the Valencia marathon of which 84 (72 males, 12 females) completed the study (all pre and post race testing). 

20 runners suffered muscle cramps during or immediately after the race. Blood and urine tests showed no differences in dehydration and electrolyte levels before, during and after the race for the runners that cramped versus those that did not.

What the researchers found was a big difference in creatine kinase and lactate dehydrogenase which are both markers of muscle damage. These markers were significantly elevated immediately post race and 24 hours in those runners who had cramps.

There was also no difference when the runners did their last training run prior to the race nor any sign of elevated muscle damage in pre race tests. Hence, the runners who cramped did not have any muscle damage (from not tapering/ resting or backing off from training). 

Almost all the training variables between the two groups were similar. Weekly mileage, previous marathons ran, etc were all similar save one variable. 48 percent of those who did not suffer from cramps did regular lower body strength training compared to 25 percent of those who cramped.

This adds more weight to my previous post that muscle cramps are more likely to occur in muscles that are tired/ fatigued to the point of damage.

I would like to add that dehydration and electrolyte depletion can hasten muscular fatigue which then causes muscle cramping.

If you're still struggling with muscle cramps, it's definitely worth giving lower limb strength training a shot and for it's other benefits as well. 

Another researcher (Del Cosco et al, 2013)who wrote about muscle damage causing one to slow down at the end of marathons suggested lower limb exercises up to 80 percent maximum weight you can lift to protect your legs from damage.


Del Cosco J,  Fernandez D, Abian-Vicen J et al (2013). Running Pace Decrease During A Marathon Is Positivively Related To Blood Markers Of Muscle Damage. PLoS One. 8(2): e57602. DOI: 10.1371/journal.pone.0057602

Martinez-Navarro I, Montoya-Vieco A et al (2020). Muscle Cramping In The Marathon: Dehydration And Electrolyte Depletion Vs Muscle Damage. J Stren Cond Res. DOI: 10.1519/JSC.0000000000003713.

McCubbin AJ, Cox GR et al (2019). Sodium Intake Beliefs, Information Sources, And Intended Practices Of Endurance Athletes Before And During Exercise. Int J Sp Nutr Ex Metab. 29(4): 371-381. DOI: 10.1123/jisnem.2018-0270.

Saturday, August 29, 2020

The Gaiter Controversy In Today's Straits Times Article

ST 290820
I read with interest earlier last week regarding the dispute between an SBS bus driver and his refusal to allow a passenger who was wearing a gaiter. The bus driver obviously felt that gaiters are not masks.
ST 240820 on page B9
A gaiter is a tube of fabric worn around the neck to keep skiers or runners warm in cold weather. They are currently popular with runners, cyclists etc in other countries because they can be pulled up to cover the nose and mouth and used as a mask.
Then in today's Straits Times (page A10, under Top of the news), the writer questioned if all masks are created equal when it comes to protection from Covid-19.

The author quoted a study (listed in my reference list) from Duke University that looked at all different kinds of face masks and measured how many droplets of saliva made it through each mask.

When the neck gaiter was tested, they found more droplets than if the person was wearing no mask or other face covering. This single layer neck gaiter was made of 92 percent polyester and 8 percent spandex.

She wrote that the researchers said the neck gaiter "seemed to disperse the largest droplets into a multitude of smaller droplets which explains the apparent increase in droplet count relative to no mask in that case".

What the Straits Times writer did not mention was that the Duke University study was done with just one person. Yes, you read correctly. N = 1. More like a case study really. Next, the way the researchers did measurements was with a phone camera and lasers. Surely, that's not a reliable way to measure particles of droplets.

I'm not sure if the Straits Times writer  even read the article. Even the authors of the Duke University study said that people are "drawing too much" from the article. The authors' intent was not to say this mask does not work or never use gaiters. That's not even the main part of the article.

If you search further, you will find that researchers from Virginia Tech did a neck gaiter study and found that gaiters "perform similarly to cloth masks and very well if doubled over." You can see the PDF document by authors Jin Pan and Linsey Marr on neck gaiters right here.


Fischer EP, Fischer MC, Grass D et al (2020). Low-cost Measurement Of Facemask Efficacy For Filtering Expelled Droplets During Speech. Sci Advances. DOIL 10.1126/sciadvabd3083. Read the article here.

Images when I googled "neck gaiter" above.

*As reported by another journalist in today's Sunday Times (page A2, Top of the news), MOH has since reiterated that makeshift face coverings such as bandanas, scarves and neck gaiters should not be used. This is under recommendations of the multi-ministry task force tackling the pandemic.

Again the Duke University case study was quoted. Again I'm wondering if the journalist even bothered to read the study itself ......
ST 300820 on page A2

Friday, August 28, 2020

Another Call For Bike Lanes In Singapore

ST 280820
After my previous article written earlier this month, it is heartening to see transport minister Ong Ye Kung suggest that certain under-used road lanes be converted to cycling and bus lanes in today's Straits Times (page A4 under Top of the news).

Well, definitely preferably cycling lanes please.

Remember Prime Minister Lee Hsien Loong's 2017 National Day Rally speech on the number of Singapore citizens with diabetes?  I suggested weight training as evidence suggests it helps with improved insulin sensitivity among people with diabetes and pre diabetes. If more Singaporeans start to cycle to run errands or work instead of taking the car, that definitely adds up too.

By riding to work, you get a workforce that gets fitter as they lose weight, save money and help the environment. Our mental health improves and we feel less stress and feel happier. In addition to having a cleaner and greener Singapore, we reduce our carbon footprint as well.

I have a particular favorite, when you ride bikes, you get the sheer joy of feeling the wind in your face - a better and greener version than driving a convertible.

Over to you Minister Ong Ye Kung and the Ministry of Transport.

Sunday, August 23, 2020

How Are Restaurants And Physiotherapy Clinics Similar?

ST 230820
The inspiration for this weeks post came from a few unlikely sources. First was a patient telling me yesterday of how a friend on Facebook shared that a physiotherapy practice was in the red and that they needed patients to ensure the practice's survival. So if anyone needed physiotherapy to please go support that particular clinic.

Then in today's Sunday Times article, the author wrote about diners who make and confirmed bookings at restaurants but do not show up. A restaurant founder (of six restaurants/ nightspots) who was interviewed said that irresponsible behavior by diners have always existed and is now becoming social norm. To quote her, "diners feel more entitled now by the fact that the restaurants need them more than they need us".

That we definitely understand. We have our fair share of patients who make appointments and after confirming, and reminders by our staff, fail to turn up.

Some jobs need us to show up in person. For the time being, restaurant staff, surgeons and physiotherapists are definitely in that category. With artificial intelligence and robot controlled arms who knows how long our jobs as physiotherapists are safe .....

Many other jobs or services are currently done with a combination of asynchronous work, video calls and others. A big thank you to all our patients who still despite a long and/ or a risky commute, come to see us.

We will strive to be totally switched on 100% and do our best all the time when treating you.
This is our promise.

*Keeping rogue diners in check. This Sunday Times article is on page C17 under the Life section today.

Sunday, August 16, 2020

Spraino Patches For Preventing Ankle Sprains?

We see lots of patients with ankle sprains in our clinic. Recently there was a patient who sprained her ankle while playing badminton with her friends.

The lack of match play and practice as all indoor courts were closed during the circuit breaker/lockdown period probably contributed to her getting hurt.

Most ankle sprains happen on the outside of the ankle. Badminton, which is a popular sport in Singapore is mostly played indoors.

The majority of ankle sprains that occur in badminton are 'non-contact'. This means players often sprain their ankles without contact with another player.

A contributing factor is due to the shoe traction-playing surface friction mechanism since only the player's shoe is in contact with the floor when the sprain occurs. This is true across various sports played indoors like floorball, basketball, handball and badminton.

Interestingly, I came across a research paper on a low friction shoe patch called Spraino that can help prevent lateral ankle sprains in indoor sports players.
Spraino patches on outer side of shoe
The researchers studied the 480 participants (that played handball, basketball and badminton) who completed the trial. The participants were above 18 and were playing at sub elite level They trained at least twice weekly, had a previous lateral ankle sprain in the last 24 months and had returned to sport prior to commencement of the research.

The participants were randomized into two groups, with one group getting the Spaino patches to mitigate the risk of lateral ankle sprains. The other group played as usual with no Spraino patches.

The adhesive Spraino patches (meant for indoor use only) were attached along the outside edge of the shoe. The front patch covers 2-4 mm of the shoe sole while the rear patch does not. The patches had a durability of 20-40 hours of activity.

The intervention group received Spraino patches and application instructions as well as instructions on how to order new patches and report adverse events. They were encouraged to use Spraino patches during all indoor sport activities. Both groups were allowed to tape or keep using any other injury preventive measure of their choice.

The researches found that Spraino was just as effective as other preventive measures (like exercise and prophylactic bracing and taping) when compared to not using Spraino. The participants using Spraino had a 53% lower incidence rate of severe ankle sprains compared to the control group.

The Spraino group was also less fearful of getting an ankle sprain and this is important since fear can be a major hindrance to sports activity.

Now, how do I get some Spraino patches for my patient. Perhaps I should email the authors. They should have named it something else though, in my opinion ;)


Lysdal FG, Bandholm T et al (2020). Does The Spraino Low-friction Shoe Patch Prevent Lateral Ankle Sprain Injury In Indoor Sports? A Pilot Randomozed Controlled Trial with 510 participants With Previous Ankle Injuries. BJSM. DOI: 10.1136/bjsports-2019-101767.