What Is Ergodicity?

Ice baths for recovery

I did not know what the word 'ergodicity' meant. I had to look it up. It means when you do a test or research on a whole group, you assume the result applies to everyone. Say you get a hundred gorrillas to flip a coin 10 times. All 10 flips ends up with a head. You then conclude that all gorillas can always flip 10 heads in a row with 10 coin flips.

Can you see the error with this conclusion? Neumann and colleagues (2021), sugests that sports scientists may inadvertently be making errors like this frequently. Their research studied the relationship between training load and recovery. If you're into endurance sports, you know recovery is really crucial.

When you train more, your fitness improves, however, it also increases your chances of injury and burnout. This has led to all sorts of research to investigate how we handle different training loads and how quickly we recover so that we can train harder without breaking down.

So, is there a link between training load and recovery? Is it possible to measure training load and subsequent recovery in a large group of people and use those results to recommend or predict how you and I or any individual would respond?

Neumann and colleagues (2020) studied footballers from a top Dutch football league club, over 2 seasons. Daily training and recovery data were collected from footballers of their under-17, under-19 and under-23 teams.

The most basic question to address is if total training load in a workout affect how recovered the footballers feel before the next day's training session? This is done in 2 ways. 

For the whole group analysis, an average training load is calculated on a given day. The analysis is repeated for each workout day and you can average the results.

For each individual analysis, you monitor every pair of workout/ recovery scores for each individual over the course of the data. This data is then averaged. 

If both group and individual data produce identical results, then the training and recovery is ergodic, meaning the results of the group studies can be applied to individuals (like you and I). If results aren't identical then oops.....

Well, sure enough, the group and individual analyses produced different results. The correlations between training load and recovery did not match up. training loads varied far more for a given individual footballer over time than they did between individual footballers on a given day. How a bunch of people respond to a single workout session does not always tell how you respond to a series of workouts. 

I recall when running cross country in secondary school how all of us in the school team were given the same workout session and each of us responded differently.

You must be wondering now if all the previous research done on training and  on large groups apply to you, or whether they are invalid. Researchers use randomized placebo controlled trials to normalise the effects of individual variation. They also report individual results to group averages. 

Read and understand the recommendations from researchers to improve your personal training/ performance and recovery. But bear in mind that we are all an experiment of one (or n = 1). Age is also a confounder. What hurts now after a certain workout did not hurt when I was 28.

Reference

Neumann ND, Yperen NWV, Brauers JJ et al (2021). Nonergodicity In Load And Recovery: Group Results Do Not Generalize To Individuals. Int J Sp Physiol Perform. 17(3): 391-399. DOI: 10.1123/ijspp.2021-0126

Don't Run More Than Two Marathons A Year

ST 300419

For the longest time, I've told my patients that the elite marathoners take up to six week to recover fully from a marathon. Mere mortals like us probably take much longer.

Yes they do start running again a few days later. The legs feel pretty much recovered after a month or so. But they don't race again for the first six weeks. That's one day off for every kilometer they raced in the marathon.

And they just restrict themselves to them just two marathons a year. If not, they don't recover fully. That hampers their preparation for the next race.

Yes, you can read from the article above that the best marathoner in the world, Eliud Kipchoge limits himself to just two marathons a year. Are you running more than that in a year?

"All the team - the coaches, the medical staff - believe that if you run many marathons, then you can't run strong marathons.

We prepare well, plan well, then run a beautiful marathon. Then come back, relax, prepare well and plan again.

The training is intense. Those running five a year, I want to meet them and ask them to describe their training.

It takes three, four months to make your mind cool and confident. You need to be ready in your head. To feel inspired.

The mind drives the body. The body can't drive the mind. If the mind is tired, you are done and when you train, you hit the wall often."

I rest my case.

Go and have a look. The article is in page C8 in today's Straits Times, under the Sports section, taken from The Guardian.

Going Bananas?

Ready to go riding with my bananas

I've written before that sports drinks cannot  totally replace your electrolyte losses during exercise. Moreover, sports drinks are manufactured and may contain flavorings and chemicals that you may want to avoid.

And if you're like me and prefer eating real food and drinking lemon water (or just plain water) rather than sports drinks while exercising, then you may be doing enough to replace the carbohydrates to fuel your exercise and even speed recovery.

A preliminary study in 2012 found that cyclists performed better for a strenuous bike ride if they had a banana or sports drink compared to water. The cyclists also had lower levels of inflammation after the ride. That study did not show why and how the carbs were aiding recovery.

The same authors did a new study that was recently published using more sophisticated techniques to track molecular changes inside the cyclist's bodies.

The subjects' underwent a intense 75 km bike ride inside the laboratory. In one ride, they drank only water while in another ride, they had water, eight ounces of a sports drink or half a "Dole" banana every 30 minutes.

The subjects' blood was tested before during and immediately the ride and even 45 hours after the ride. Inflammatory blood markers and metabolites were assessed during and after to test how much stress was taken by them.

When the cyclists' drank only water during the ride, relatively high levels of inflammatory markers were found. These same markers were much lower if the cyclists' had consumed the banana or sports drinks. Metabolite profiles were less stressed regardless of whether they had the banana or sports drink compared to without.

One obvious difference was those cyclists' that ate the bananas had blood cells that produced less COX-2 (a genetic precursor of an enzyme). This was not seen if they drank only water or had the sports drink.

For those interested, COX-2 enzyme stimulates prostaglandin production, which increases the intensity of inflammation. Those of you who take inflammatory medication like Arcoxia or Celebrex tablets note that they are COX-2 inhibitors. They help reduce inflammation.

This study suggest that bananas might perform comparably although it is unknown how bananas affect the cells' gene expression. So instead of popping pills like Arcoxia and Celebrex prescribed to you, you may want to eat more bananas and ginger.

It was calculated by the researches that half a standard banana provided similar carbohydrates as a cup of sports drink and the cyclists' had half every 30 mins. Bear in mind your needs may be different. Some cyclists' also complained of feeling bloated after eating that amount of bananas.

So be warned before you go bananas over ingesting bananas in your next long ride or race.


References

Nieman DC, Gillitt ND et al (2012). Bananas As An Energy Source During Exercise: A Metabolomics Approach. PlosOne. DOI:10.1371/journal.pone.0037479

Nieman DC, Gillitt ND et al (2018). Metabolic Recovery From Heavy Exertion Following Banana Compared To Sugar Beverage Or Water Only Ingestion: A Randomized, Crossover Trial. PlosOne. DOI:10.1371/journal.pone.0194843

*Note that Dole Foods which sells bananas funded both studies. However, they company did not have any involvement in study design, data collection, analysis, decision to publish or preparing the article.

Massage Does Not Flush Lactic Acid From Your Muscles

Picture from our Sports Massage course in July 2013

Finally, a published paper that suggests massage does help reduce inflammation in your fatigued muscles.

Hey, didn't the title say something else? Please read on to find out how massage reduces inflammation.

Many massage therapists, physiotherapists etc will say that massage can relieve your pain, DOMs (delayed onset of muscle soreness), promotes circulation, flushes your lactic acid/ toxins from your body, relieves your joint strain etc. However, published evidence does not totally support their claims fully.

Well, Sefton and colleagues (2012) can finally set the record straight. Massage cannot push toxins from muscles to your bloodstream. It also cannot flush lactic acid from your muscles. So do not believe anyone who tells you otherwise.

What massage can do is it can soften your fascia (which is found all over your body covering your muscles beneath your skin) and make your tight muscles relax. It can also remove adhesions between fascia and muscle (which can restrict your movement).

Crane's study also found 30 % more of a gene that helps muscle cells build mitochondria (mitochondria turns a cell's food into energy and facilitate its repair).

Well, great news for runners, athletes etc who rely on limber joints and muscles for pain free movement to ensure you perform optimally.

This also mean that regular massage can let runners, athletes etc tolerate more and harder training since it can hasten recovery and allow them to ability to train hard again two days later.

Other research suggests that besides reducing inflammation, massage also improves immune function. This suggests it may also help chronic diseases.

For more on Sports Massage please also see this and this.

Calling all runners, athletes, patients with chronic pain, call our clinics to book your Sports Massage appointment.

References

Crane JD et al (2012). Massage Therapy Attenuates Inflammatory Signaling After Exercise-Induced Muscle Damage. Sci Transl Med 4, 119ra13. DOI: 10.1126/scitranslmed.3002882.

Rapaport MH, Schettler P et al (2012). A Preliminary Study of the Effects of a Single Session of
Swedish Massage on Hypothalamic–Pituitary–Adrenal and Immune Function in Normal Individuals. J Altern Complement Med. Author manuscript; available in PMC 2012 March 01.

*Many thanks to Lim Ting Jun for the articles.

Morning Run Or Sleeping In

I got a question from one of my athlete patients just a while back, "I didn't sleep well. Which is better: going on my morning training run or sleeping in?"

My answer to the athlete was it depends. If it was just an occasional situation where say you stayed up to watch TV, you can still go for your training run.

But, if you haven't been sleeping enough over an extended period of time, it'll be better to sleep in. Rest is when the body heals, repairs and recuperates itself to adapt to the training stresses you've put your body through.

Just like in body building, the muscle grows when the body is resting not when you're lifting weights. In fact the muscle breaks down while you're weight training not the other way around. When you allow the muscle to rest it rebuilds itself bigger and stronger.

Not sleeping enough means not giving your body time to recover. Focus on your sleep needs first. When you've rested enough, you'll feel better and can make time to run later in the day.

Bear this in mind, sleep is a necessity not a luxury, especially for athletes. It's a training tool, running on empty won't get you far. For the rest of us mortals, skipping on sleep to fit in running, working and our personal lives will cause more problems than it solves.