Sunday, February 27, 2022

Super Pants Instead Of Super Shoes?

When someone mentions exoskeletons, I immediately think of 'Robocop', a film from 1987 (film poster below). Those of you who are old enough to remember watching Robocop starring Joel Kinnaman will understand what I'm trying to write. 

Why am I writing about exoskeletons? Well, it seems they may be the next big thing for runners after super shoes like Nike's Vaporfly came onto the market in 2017.

Wearable exoskeletons were invented to assist walking or running, especially to help carry heavy loads. Here's an early invention from a paper published in 2018 (Nasiri et al 2018). A spring loaded exoskeleton (pictured above the movie poster) worn around the waist and clamped to the upper legs that helps the rear leg forward with each stride. The researchers showed an improvement of 8 percent (compared to 4 percent with the Vapourfly).

However, if you looked at the design, it looks too cumbersome to run with. Probably it would be banned by World Athletics too.

A more recent paper published last year by South Korean researchers showed how a relatively simple design can improve running economy by 2.5 to 4.7 percent. 

There is a band around your torso, held up by suspenders (pictured above).There is also one compression band around each thigh, which is connected to the torso by an elastic. It weighs just 1.3 pounds and sticks out from your body by not more than an inch. Surely that can pass off as a pair of compression tights that will not be deemed illegal by World Athletics standards?

There was also another paper from a group of researchers in China that studied a unpowered exoskeleton that improved running economy by 7.2 percent (Zhou et al, 2021)

Rememeber so many world swimming records were broken after the now infamous polyurethane Speedo Fastskin LZR 'super suits' were introduced in 2009 and FINA (World Swimming Federation) subsequently banned them. Well, some of those timings still stand. 

Similarly, road running/ racing shoes cannot be used (for World Athletics races) if the midsole is thicker than 40 mm or if the shoes contain more than 1 carbon plate. Running spikes can only be 20 millimeters (mm) thick (down from 25) with effect from 2024. 

This may have led to the 400m hurdles men's world record By Karsten Warholm at the Tokyo Olympics last year. That world record and any other records set by these super spikes may last a whole lot longer when the super spikes are outlawed in 2024. Just like the swimming world records set wearing those 'super suits'.

Perhaps World Athletics should write some rules with these soon to be developed super pants. Remember you read about the 'super pants' here first.

References

Nasiri R, Ahmadi A and Ahmadabadi MN (2018). Reducing The Energy Cost Of Human Running Exoskeleton. IEEE Trans Neural Sys Rehab Eng. 26(10): 2026-2032. DOI: 10.1109TNSRE.2018.2872889

Yang JH, Park JI, Kim JH et al (2021). Reducing The Energy Cost Of Running Using A Lightweight, Low-profile Elastic Exosuit. J NeuroEngineering Rehab. 18, 129. DOI: 10.1186/s12984-021-00928-x

Zhou T, Xiong C, Zhang J e al (2021). Reducing The Metabolic Energy Of Walking And Running Using An Unpowered Hp Exoskeleton. J NeuroEngineering Rehab.18, 95. DOI: 10.1186/s1298-021-0093-5

Sunday, February 20, 2022

Does "Good" Running Form Make You Run Faster?

For running fans and runners, there is currently a nice Tracksmith video going around featuring *Nick Willis, a 1500m Olympic medalist (silver and bronze). The video is on how he's trying to run a sub-4 minute mile for the 20th consecutive year and how beautiful and smooth his running form looks.

Nothing against Nick Willis, the runner I think who has the best running form belongs to Sebastian Coe (pictured below). If you are old enough to remember Seb, he's the only runner to win back to back Olympic 1500m races (in 1980 and 1984). Also a former world record holder for the 800m, 1000m, 1500m and the mile. My friend Nai Min even named his older boy after Coe.

Seb Coe was much faster in his prime and also finished 2nd in the 800m at the Olympics twice. But Seb never did run 19 consecutive years of sub-4 min miles. 

What made Seb Coe's and Nick Willis' running form look so good is that they make running fast seem easy. So most of us assume that such runners with nice form must take less energy compared to a runner with ungainly and/ or awkward running form.

But the question is, is a nice looking stride (or running style) a fast one? Previous studies have shown that the way you look when you run does not predict how fast or efficient you are.

A new study proposed 2 ways of quantifying running form. Duty factor, which is how long your foot stays on the ground as a fraction of your total stride cycle and a proprietary Voloden scale using 3D motion analysis to quantify how much 'aerial' or float time. The study used 52 trained runners with an average of 1:31 hrs for their half marathon time and they had been runners for 8 years.

Runners with a high duty factor (more time with feet on the ground) tend to land on their heels bend their knees and ankles more and propel themselves forward rather than upward. Runners with a low duty factor tend to land on their mid or forefoot, keep their legs straighter and propel themselves upward. Ditto for the Voloden scale.

Both ways actually do not tell us anything about eficiency. Perhaps, the runners in this study, having run for 8 years have already optimized their running form. It may be possible using artificial intelligence to tell the difference in a more diverse group of runners and non-runners. The authors conclude that there is no link between efficiency and form

The researchers also advised that "running coaches should not try to modify the spontaneous running pattern of runners."

Why did the authors bother with the study? I'm still asking myself that question.


Reference

Patoz A, Lussiana T, Breine B et al (2021). There Is No Global Running Pattern More Economic Than Another At Endurance Running Speeds.Int J Sp Physio Perform 10: 1-4. DOI: 10.1123/ijspp.2021-0345.


*For track fans, there is also a nice GQ article on Nick Willis trying to achieve his 20th consecutive year of running a sub-4 minute mile.

And for those of you who remember, Sebastian Coe lost the 800m (despite being the world record holder and favourite to win) at the 1980 Moscow Olympics (pictured below). 


Coe looked untroubled at lap 1 of the race (left of picture above), was desperate near the end of lap 2 (right picture). And still disbelieving at the medal ceremony (inset).  

However, he picked himself up and won the 1500m over the favourite and world record holder Steve Ovett only a few days later.

Almost home - 30m to go

*pictures taken with my iPhone XI Pro from one of my favorite books "The Olympians" by Sebastian Coe with Nicholas Mason

** Nick Willis did it! He clocked 3:59.71 minutes in the the mile at the Millrose Games in New York on 29th January. 20th consececutive year of going under 4 minutes fot the mile. Amazing!

Sunday, February 13, 2022

The Big Hand Syndrome

Since my accident last year, my wife and I have been going for longer walks (since I could not run then). We enjoy the time together since it gives us a chance to share our thoughts, talk things out and simply hang out.

What we have noticed is that our hands are often swollen at the end of these hour long walks. It never happens when we go for a run, only after a walk.

Looking through some endurance related forum boards revealed that this is fairly common among ultra runners too. Ultra runners complain that their hands look like a "blown up rubber glove" or having fingers that feel "tight and hard to bend".

I've tried looking for research regarding the causes of hand swelling during walking/ moderate exercise, but not much can be found. It has been suggested by one published report that one out of four people will experience swollen fingers/ hand while walking. Women seem to be more commonly affected than men. 

There have also been suggestions that arm motion, heat-related issues or metabolic changes may play a part but nothing seems conclusive. 

One study (reference below) referred to the post-walking hand swelling as the "big hand syndrome".

It is suggested that hand swelling may be a result of the way our bodies and blood vessels respond to blood flow during exercise. Since exercise increases blood flow to our heart, lungs and our lower limb muscles (while walking) blood flow to our hands is reduced. This makes our hands cooler while the blood vessels react by opening wider, leading to swelling in the hands. 

As you contiune on your walk, your muscles try to dissipate the heat generated by pushing blood to the vessels closest to the surface of your body. This response makes you pespire and can also contribute to hand swelling.

In hot, sunny and extremly humid Singapore, skin blood flow and circulation may be compromised and regulation of body temperature will be more difficult, even during light exercise. Vasodilation (opening of blood vessels) occurs to cool our bodies by pespiring.

Depending on how much water we drink and our bodies' ability to cool itself, this may create a fluid imbalance, leading to excess fluid in the skin and underlying tissues.

Some papers also suggest fingers/ hand swelling can be a early sign of hyponatremia, but I don't think so. It would be very unlikely that one can get hyponatremia from walking for an hour or two. 

Trust me on this, I've had hyponatremia before and the more serious and obvious signs and symptoms include vomiting, cramps, giddiness, disorientation, diarrhoea and convulsions. I had most of those symptoms and that landed me in the hospital intensive care unit (ICU) for a few days after a ultra running race in Hong Kong back in 2000. Now you know what I mean when I say I'm a cat with 9 lives. I've definitely used up a few of those 9 lives. 

Unfortunately, there is no fool proof way to reduce or prevent exercise related hand swelling. What we found helped was opening and closing your fingers frequently when walking and/ or making exaggerated arm swings or circular actions with your elbow. 

Taking off your rings (like my wife in the picture above) and loosening your watch strap if you wear one will make it less uncomfortable.

All smart endurance athletes know it is important to pay attention to their bodies and it's natural to wonder if suasage-like fingers are symptoms of something sinister. Fortunately, hand swelling is just a slightly annoying, but not harmful, response to exercise. 


Reference

Ravaglia FF, Leite MG Leite, Bracellos TF et al (2011) Post Ambulatory Hand Swelling (Big Hand Syndrome): Prevalence, Demographics And Association With Dog Walking. ISRN Rheumatol. DOI: 10.5402/2011/65995

Sunday, February 6, 2022

Isometric Exercise Training Trumps HIIT

Isometric hand grip training
An article in the Straits Times last year showed that an increasing number of Singaporeans have hypertension or high blood pressure. 

This is not just in Singapore, hypertension is a global health problem that is largely treated by anti-hypertensive medication. However, even though anti-hypertensive medication is mostly effective, other than being costly over the long term, it has adverse side effects and also poor adherence rates. My own grandmother used to take one pill a day, then she reduced the dose to half herself before stopping altogether.

Traditionally, moderate intensity aerobic exercise is currently recognised as the recommended modality for managing blood pressure problems. Current exercise compliance to benefit long term cardiovascular risk is also poor. Hence, a different approach may be needed to manage hypertension.

The paper referenced below investigated the effects of isometric exercises versus high intensity interval training (HIIT) to find out which is more effective at reducing resting and ambulatory blood pressure (BP).

Both IET and HIIT were found to be effective, however IET was significantly more effective at reducing resting BP compared to HIIT. Systolic and diastolic BP were reduced by 8.50 mmHG and 4.07mmHG after IET versus 2.86 mmHG and 2.48 mmHG following HIIT.

HIIT lessened the resting heart rate significantly by 3.17 beats per minute (bpm) versus 1.34 bpm for IET. 

Duration of exercise, subject's medication status and time of diagnosis of hypertension had no effect on the results.

Compared to HIIT, IET had superior results in the management of resting BP with reductions similar to or greater than anti-hypertensive medication. HIIT was still found to be highly effective at reducing resting BP and may have wider physiological benefits than IET since it was more effective at reducing resting heart rate. 

Teaching patients to use IET to reduce hypertension should definitely be considered. Most of the studies that studied IET used hand grip exercises for the upper limb and stationary wall squats or leg extension for the lower limb. Cycling intervals were the most common for HIIT studies.

The authors concluded that getting patients with hypertension to do IET for controlling their blood pressure should be considered, while HIIT better for maintenance of good health.

Now you know IET trumps HIIT when it comes to lowering blood pressure.

Reference

Edwards J,  De Caux A, Donaldson Jet al (20). Isometric Exercise Versus High-Intensity Interval training For The Management Of Blood Pressure: A Systematic Review And Meta-Analysis. BJSM. DOI: 0.1136/bjsports-2021-10442.

*Thanks to Megan for getting me the article