Wear That Helmet …

Personal protective equipment is big news presently.

Cyclists in Melbourne are presently restricted to an hour’s ride a day and no further than 5km from home. Traffic volumes are down but it seems that some drivers see this as an opportunity to drive faster than usual. Where I live cyclists are not quite so restricted but the  roads I ride are open highway – all the traffic is going fast.

It’s worth remembering that Kreisfeld & Harrison 2019 examined the injuries sustained by cyclists and found that about half of those that died did so because of head injuries. So wear that helmet.

Hang on, is that an endorsement? The figures are for Australia. Helmets are compulsory in Australia and compliance is high. Helmets didn’t do a lot for those that died but hey …

there are other good reasons.

Helmets provide excellent protection from Magpie attack. The bird in the video staunchly defends its stretch of road. Where most Magpies are content to swoop without making contact this one routinely hits you in the back of the head. They always attack from behind. I have seen a fox running flat out to escape the attention of a pair of these feisty birds.

 

AIHW: R Kreisfeld & JE Harrison 2019. Pedal cyclist deaths and hospitalisations, 1999–00 to 2015–16. Injury research and statistics series no. 123. Cat. no. INJCAT 203. Canberra: AIHW.

Plateau …

To recap very briefly … Old couch potato is enticed onto a bicycle and it reawakens something within that has been dormant for quite a few years and he likes it.

The regime goes something like this …

  • cycle 5 days a week – average 250 km/week in recent weeks.
  • weight training 2 days a week.
  • Diet – low carb high fat (keto) ovo-lacto-vegetarian, lunch and evening meal nuts in between (usually no breakfast). Protein supplementation to reach ~1.5g/kg of ideal weight.

No calories have been counted.

Too many progress reports would become boring but not enough could give the impression that I was trying to conceal a failure.

Initially, as always, the weight simply fell off …I weighed myself the day I bought the first bike. The diet started three weeks later. The dots represent every Monday since. Somehow I always seem to weigh more on Mondays than on other days, how does that work? If I changed days would that phenomenon follow me?

About five weeks ago the weight loss ground to a halt. 13 kg of ugly weight gone – a guillotine could not have done better (average weight of a human head is only 5kg). Along with it went more than four inches from my waist.

A successful diet is one where an overweight person intentionally loses more than 10% of their body weight – 11kg of 93 = 12% – and keeps it off for more than a year. The foundational study by Stunkard and McLaren-Hume 1959 found that of 100 obese individuals only 2 were in fact successful.

So this is the time to ponder a few important questions.

  • Why does weight loss stop?
  • What can be done to prevent a big bouncing relapse?

It takes a certain amount of food to maintain a particular weight in the presence of a certain amount of exercise. That’s simple enough but how much varies from person to person and even for one person at different weights. So consider firstly the unlikely case of someone eating the same number of Calories and doing exactly the same amount of work every day. Let’s assume that at the outset Calories in is less than Calories out – the stage is set for weight loss.

There are two forms of energy store in the body glycogen and fat. Glycogen is stored in the liver and muscles.  It is readily available energy, the first to go on a diet and it takes three times its weight of water with it. That’s the easy part. Once we get onto mobilising fat things slow down.

But progress goes on. As weight is lost the energy cost of the work done decreases and the size of the Calorie deficit decreases with it. Weight loss slows and will eventually stop.

In reality it stops well before the point that simple maths predicts for a number of reasons. Humans have not always existed in a world awash with food. We have evolved mechanisms that help us survive food shortages, endure periods of starvation. The recently emptied fat cells pump out lipoprotein lipase, which tells  the brain “hey, we’re starving”. Leptin, the hormone that tells us we have eaten a sufficiency, diminishes. Ghrelin, the hormone that makes your tummy grumble, increases. Peptide tyrosine-tyrosine and cholecystokinine increase. These things conspire to increase your appetite.

Meanwhile the resting metabolic rate goes down in response to reduced thyroid hormone (T3)  and reduced activity in the sympathetic nervous system. Levels of a group of proteins that uncouple metabolism from energy production (analogous to wasting petrol by revving the engine with the clutch disengaged) diminish. In the good times some excess energy was simply turned into heat now faced with a famine nothing is being wasted.

Yet more energy can be saved by reducing nonessential activity.

When the recently obese person is compared to a never obese person of the same weight and body composition their energy economy is quite different. All the differences are to the dieters’ disadvantage. Failure beckons and I’ve traveled that route before.

However, only 98% fail.

So far I’ve relied rather heavily on Exercise Physiology for Health, Fitness and Performance by Sharon Plowman and Denise Smith. The next section owes much to a paper by Wing and Phelan which can be found <HERE>.

They paint a picture that is less bleak, as many as 20% manage to keep the weight off, and they present some of the characteristics of those that do identifying six key strategies for long-term success at weight loss …

  1. engaging in high levels of physical activity;
  2. eating a diet that is low in calories and fat;
  3. eating breakfast;
  4.  self-monitoring weight on a regular basis;
  5. maintaining a consistent eating pattern; and
  6. catching “slips” before they turn into larger regains.

In addition those who initiated weight loss because of a medical trigger such as a relative having a heart attack were more likely to succeed.

Holidays and weekends are dangerous moments and those that maintain the same regime through these periods as they do the rest of the time do best. Once relapse is underway prospects are poor. Depression bodes ill.

I can put a tick against items 1, 4 and 5. Item 6 is really what item 4 is all about and hasn’t yet been put to the test. My most obvious vulnerability is relying on satiety to determine portion size.

But, oh dear, a low fat diet and eating breakfast are not on the agenda.

I have no doubt that these are common practices in those that succeed in long term weight maintenance but my conjecture is that these have not contributed to their success. Clearly these are remarkably self disciplined people. The discipline they have imposed on themselves is a very orthodox one. Dr John Harvey Kellogg told the world that breakfast is the most important meal of the day to the certain benefit of the food producers but there is no evidence that it is to the benefit of the rest of us. On the other hand there is some evidence in favour of intermittent fasting. I tend not to eat after 9pm and defer breakfast until noon giving my pancreas a 15 hour rest on the majority of days.

Fear of fat is another well entrenched orthodoxy. I’ve lost weight on a high fat diet. It defies logic that I can’t maintain weight on a high fat diet.

These two points are examples of well-person confounders – baggage that is carried along with useful characteristics that really do contribute to health.

Or at least I hope that’s the case!

They All Think They’re Churchill …

The daily dose of Dan and the other politicians is stirring stuff …

We will fight on the beaches, we will fight on the landing grounds, we will fight in the meatworks …

and there’s every chance we will fight in the supermarkets that are suddenly meat free zones. Thank goodness I’m a vego. And what is it about toilet paper?

Stage 4 restrictions for the majority of Victoria’s population Stage 3 for the rest of us. Almost no valid reason to let anyone into your house only four valid reasons to leave it. House arrest. There does still seem to be a social licence for these measures. The other day’s Herald-Sun had some snippets from half a dozen persons in the street all in favour. The tone crystalises into putting up with short term pain for long term gain.

There is emerging some disquiet and disobedience. The utter nutters are in the vanguard declaring Covid19 a hoax or blaming it on the 4G network. Just to make sure that they have no protection by way of civil rights Mr Andrews has declared a state of emergency giving the police supernatural powers, after all, these people are not Black Lives protesters or union members picketing a building site.

Following the Covidiots are the invincibles, mostly young with little to fear beyond the death of a grandmother here and there. They don’t believe that Covid will kill them. The government tells them it will but mostly that’s untrue.

The current strategy is to limit the spread of the virus by severely limiting the movement of people. I do believe it will work. I expect that in a couple of weeks case numbers will begin to come down quite quickly. But then what?

The population of Australia is 25 million people. As of yesterday there had been 18,318 cases of Coronavirus infection. That means that 99.94% of the population are naive to this virus. Unless there are no cases left in the community there will be a third wave once restrictions are lifted. If there are indeed no cases we will all be safe … until we open our borders.

Will there be social licence for stage 5 restrictions when the populace realises that this isn’t short term pain?

Hot Air …

Over the last few days I’ve estimated my VO2max by some of the many methods available to those unfortunate enough to lack a gas analyzer and cycle ergometer.

The first couple of methods don’t involve getting up out of your chair, the second is the simplest – the inputs are just your resting pulse and your age. The next two involve exercise. The inputs are your weight and active pulse or measured power.

The Rockport test doesn’t involve exercising at maximum capacity, at least not unless you are totally out of shape, therefore it is suitable for elderly gentlemen. The six minute power is meant to be a maximal effort.

It is interesting how close the results cluster together. Whether that is anywhere near a lab measured VO2max is an unknown.

Method

How

Link

VO2max

World Fitness

Questionaire

World Fitness

47

Resting Pulse

Take pulse

MDApp method 1

42

Rockport

Walk 1 mile fast

MDApp method 2

39

6 minute power

Cycle

Michael Konczer

40.6

VO2max peaks in young adults and then declines at about 1% a year. Young and middle aged men can halve the rate of decline by regular vigorous exercise but the rest of us are stuck with it. It is largely the consequence of a declining maximum heart rate. The second most important culprit is increasing body fat.

After 70 it’s supposed that VO2max drops off a cliff but the evidence is getting pretty thin at that stage. Clearly nobody told Giuseppe Marinoni who set the Hour Record in the men’s 80 to 84 category last year by cycling 39.004 km.

Great things are still possible.

Another Glass of Red …

Cheers.

It’s from 2017 grown and made in our own little slice of paradise.

We enjoyed another little sojourn in the bush. We live in splendid isolation and prefer to camp in splendid isolation. The only other human that we came close enough to talk to was at the fuel stop going and coming back and that is the one closest to home in any case.

How isolated is isolated? This is the map of a morning ride. It’s 13km from the bottom to the top of that red line so a swathe of country about 50km wide. There’s not a town or a named feature on it, one of the things I love about Australia.

Best bird in the couple of days was Gilbert’s Whistler and we came across this little guy …

We also came across the Shire of Hindmarsh Ranger, his job is to enforce the local laws …

 

How Fit … ?

In The Hitchhiker’s Guide to the Galaxy, we learn that the answer to the Ultimate Question of Life, the Universe, and Everything is 42 which I’m sure is correct. If we ask Strava how fit I am the answer is …

154.

Not bad, eh?

In fact three point six (recurring) times greater than the meaning of everything but notice that back in February when I started tracking my bike riding on Strava my fitness was zero. As far as I can recall I had a pulse and could ride around the block – zero it could not have been.

It looks as though my fitness has improved and in the last couple of months there is the suggestion of a plateau. The dotted line at the right hand end is a prediction of what would happen if I quit exercise. In broad terms I wouldn’t argue with all that but what does the 154 represent? If you are a 152 am I fitter than you?

There are a number of metrics in Strava and other fitness and training apps for which you can find an explanation but not a definition or a formula. Strava’s explanation from their glossary is …

While fitness is a complicated concept, it can be simplified to an accumulation of training. The Fitness Score is calculated using Training Load and/or Relative Effort to measure your daily training, and an impulse-response model to quantify its effect over time. This will intuitively capture the development of fitness from training, as well as the loss of fitness during a break.

and you won’t find Relative Effort or Training Load in the glossary.

So training volume goes into a black box where it is fiddled with in mysterious ways and out comes the answer in unspecified units.

Fitness is indeed a complicated concept. The word fitness has a great deal of work to do. At it’s broadest it means capacity to do something. It’s gets a lot easier to get a handle on it when you define the something. Let’s make that endurance exercise. Now we can consider the factors that contribute to capacity. They may be physical characteristics that the athlete in question is stuck with such as leg length or characteristics that are amenable to manipulation such as weight and body composition.

Endurance sports are various ways of turning food into distance covered with the prize going to the fastest person to the finishing line. Oxygen is required to burn the food. A good measure of fitness therefore is the maximum rate at which oxygen can be utilised or VO₂max. It comes in two flavours – absolute and relative.

To measure VO₂max accurately is a laboratory task. Inspired air is compared with expired air to find the amount of oxygen removed by an athlete as they perform a steadily harder task until the athlete cannot continue or the oxygen consumption reaches a plateau. The difference in humidity and temperature of inspired and expired air has to be addressed. A mask is worn throughout.

The Absolute VO₂max is simply the number of litres of oxygen taken up per minute going full gas. For relative VO₂max you divide by weight and express the result in millilitres per minute per kilogram. In a series of tests for a single athlete it’s handy to have both in order to distinguish between the contributions of adaptation and weight loss. If comparing one athlete with another relative VO₂max is more useful.

As the saying goes “Test is better than guessed” but it requires attendance at a lab and a fee in the vicinity of $200 a time. It’s not a one off – if it’s worth doing then it’s worth doing regularly to ensure that training is having the desired effect.

There are ways to estimate VO₂max rather than measure it. These don’t involve wearing a mask and analyzing expired air. Some don’t even involve exercise!

If you are interested in an estimate at the level of a general health interest try the online calculator at worldfitness.org. In my case I think the answer was a little flattering. Four different ways are on offer at MDApp including one based solely on resting heart rate and age. For the other three you will need to do some exercise. The Rockport Walking Test involves a one mile walk. The formula includes a refinement that reduces the error involved in being the wrong gender.

For the price of five or six visits to the laboratory you can buy a smart watch that will estimate your VO₂max and tell the time. Passler et al 2019 (International Journal of Environmental Research and Public Health) tested a bunch of wearable devices and concluded that they don’t do a particularly good job of measuring energy expenditure or calculating VO₂max.I believe they are reasonably good at keeping time and some play music.

If you are male and have a power meter you can estimate VO₂max by investing six minutes of your life in all out effort on the bike and plugging the result into a calculator provided by Michael Konczer. I haven’t been able to find a formula for females. So sorry girls – you’re walking. The formula used is …

It is an informative site with a table that you can consult to see how your result stacks up.

Regular testing is the ideal way to keep track of progress. A six minute test over the same course is directly comparable especially when measured by power rather than distance because that reduces the problem of variable winds. Estimating VO₂max from it may not be as exact as a lab measurement but the error will be much the same each time and it gives a value that will serve well enough for rough comparisons with other athletes. Friends will be delighted to hear of your improvement.

VO₂max is a very handy metric but by itself it will not tell you who will win the next race. Economy is the ratio of work done to energy expended and this varies from athlete to athlete as does the ability to tolerate workloads close to maximum. According to Allen, Coggan and McGregor VO₂max is to be found somewhere between 106 and 120% of functional threshold power (FTP).  If you know all those numbers for every entrant your crystal ball has a better chance. And the higher your VO₂max the better the chance that it will be you.

Back in the Zone …

Back to the daily grind. It was strongly tipped that our fearless leader would lock the entire state down again but instead he has mandated masks. If nothing else it will improve the appearance of the Victorian public. But I digress. The theme was power meters.

Functional Threshold Power measured on the bike is a handy way to adapt training intensity to a particular individual. Zones based on heart rate are another easily accessible method and a chest strap is less expensive than a power meter. Exercise physiologists have laboratories and all sorts of tech and therefore the means to make things way more complicated. By and large, though, the physiologists prefer a three zone system rather than five or seven,

You can find a good post (and podcast) by Dr Shawn Bearden on the topic <HERE>.

The zones or domains have nice practical names moderate, heavy and severe. The boundaries are only slightly fuzzy, rather than mostly arbitrary, and correspond with changes that can be demonstrated in the laboratory.

During moderate exercise oxygen consumption increases with work load. If you drew a graph it would be linear. At the same time lactate levels rise very little. As the intensity increases there comes a point where the slope of oxygen consumption increases and you enter the heavy zone. Round about the same point the lactate level heads gently upwards. FTP is close to the top of the heavy domain.

The moderate zone is easy, efficient and sustainable. The heavy zone is less efficient but still sustainable. Increase the load further and lactate begins to rise more rapidly, breathing becomes laboured and exhaustion beckons. The severe zone is inefficient and unsustainable but essential for a place on the podium.

from https://www.highnorth.co.uk/articles/cycling-training-zones

The boundary between moderate and heavy sits at about 65 to 70% of FTP or at the top of zone 2 in the Coggan model that I discussed recently. Severe kicks in at the top of zone 4 (roughly).

Race pace for endurance events is in the heavy zone but should you train there? Proponents of polarised training say no. Training at moderate levels will build stamina and pace efficiently with the athlete adapting and recovering from fatigue optimally. Top this off with some training in the severe zone.

So perhaps the most important use of a power meter in training is to ensure your easy days are easy enough. You don’t need a power meter to tell you when you’re going flat out.

A Brief Escape …

The accursed Covid has certainly changed our lives. Gayle and I were not intending to spend the winter in Victoria. Another road trip to the tropics looked good. It wasn’t to be. Nonetheless we are better off than many. Locked in a tower block apartment has got to be a nightmare. Fortunately for us we live in a sparsely populated rural location which wasn’t locked down when restrictions were reimposed on Melbourne.

We can’t go far but western Victoria is available and we’ve been keen to go to Woomelang for a look at their little silos. We camped by the lake at Wooroonook the first night. It’s a spot we can reach in little more than an hour. We were blessed with a clear sky, a perfect night for a glass of red by a campfire.

The landscape is pretty well flat but 8km away there is an isolated hill that gives a good view of the surrounding country. The mountain bike and I made it to the top of Mt Jeffcot. The view was splendid and the descent was terrifying.

Strava segments are named by their creator. Presumably this one is not part of a naked bike ride. And for a timid rider like myself you’d want shorts on to hide the fact that you’d packed your daks.

After lunch it was off to Woomelang for some small scale silo art. There are seven portable silos with work by a variety of artists scattered around. This sort of silo is often called a field bin. The artists that were issued with corrugated ones got the short straws. They were definitely at a disadvantage. I was particularly struck by the Western Pygmy Possum and the Mallefowl …

The camp that evening was in Black Box woodland at Lake Albacutya.

In the morning it was back on the bike …

The lake was dry as it usually is. When the Wimmera River carries enough water it spills through Lake Hindmarsh to Albacutya and then into Wyperfeld National Park. It hasn’t happened so far this century! It does have a nice concrete boat ramp for the next occasion.

A walk turned up some nice birds including Chestnut-rumped Thornbill and Scarlet Robin. My second cuckoo for the “spring” was calling prominently – Pallid Cuckoo.

After that it was home again, home again as a westerly front blew in bringing a gale and some heavy rain.