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Don’t trust your trainer!

OK the headline is a little bombastic but there are a few reasons why you should genuinely doubt whatever it is your trainer tells you. I am not normally a trainer-basher and a really like a few trainers that I know. However, the threshold (which they will readily admit) to becoming a trainer is not very high. More worryingly, it has little to do with actual science.

I recently ran across an Outside article (found here) which dispelled a lot of myths that persist in the industry. A lot of times these articles are fluff pieces, but this one includes a couple of pet-peeves of mine that raise my intellectual hackles every time I hear them.

First let us review what “scientific” means when I talk about “scientifically proven”. When I say that, it broadly means that science guy studied an idea blind or double blind to the results and then plotted the results against a control group. The trend lines tell the story. If the trend lines for the non-control group is noticeably different than the control group, you may have a causative effect for whatever you are studying. This is a really good standard. You may lack a control group or worse, rely on self-reporting (which is susceptible to the reporters biases) but even in those cases researchers figure some sort of compensating control so they can trust their results. If you get evidence that is not generated this way, we call it anecdotal. Anecdotal evidence is anything that happens to you or a small group of people with little to no regularity. Get enough consistent anecdotal evidence and it can cross the “scientific” threshold into a noticeable trend. Your buddy telling you “a couple guys I know who use XXX product see XXX result” is anecdotal.

When you start applying that standard to your judgments you start seeing things differently. Why, exactly, is HGH banned as a PED? Why is marijuana illegal? Why do people insist on small class sizes (oh yes, look up that sacred cow)? Why do we think sugar (look this one up too) makes kids hyper? It gets so bad that you will find yourself immediately doubting what anyone says to you unless you see some sort of believable evidence to support their claim.

When it comes to sports science there is a plethora of short tidbits of wisdom which, it turns out, have very little sound scientific evidence supporting it. For example, stretching to prevent injury. Scientifically, this hasn’t been proven, and in the studies looking at it, the stretching group had an injury rate slightly higher than the non-stretching group. Another example is salt and cramping. I have always been fascinated with the obsession with sodium replenishment in sports because, while sodium is an important part of the cell, it is generally understood that the body needs very little sodium supplementation and the use of salt in the cells doesn’t go up under exercise. Indeed, when studied, no link between sodium supplementation and the prevention of cramps is found. In fact, science hasn’t even proved that mild dehydration really effects performance that much, if at all. The old adage “drink before you are thirsty” is not based in reality. It should be “drink when you are thirsty” which makes a wicked amount of sense. We wouldn’t have survived evolution if our bodies were that bad about telling us when we need to replenish our internal water supply. “Fat burning zone”, don’t even get me started. Let’s just call it “complete hogwash”. 

Facts and educated opinions underpin a successful modern society and, in the sports world, it can help clear up a ton of misconceptions. Cross-check everything your trainer tells you against trusted sources. Not everything on the internet can be trusted, but you are normally only a few clicks of a google search away from sound scientific evidence.

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HRM Blues

When I first started thinking about doing triathlon, indeed before I even ran 10K all in one run, Sarah had bought me a Garmin 910XT triathlon watch. This watch came with the familiar chest strap heart rate monitor, although this one was the “premium” version which meant that the strap was a bit nicer.

premium-hr-monitor-1-web

I never bothered seriously reviewing this device because it generally worked OK, until it didn’t. To be clear I never really liked the chest strap because even though it was the ‘premium’ version, it still wasn’t very comfortable. After about three months my heart rate monitor would randomly stop reading heart rate (drop out) or read so ridiculously low (reading 85 when it should be 160) that the data couldn’t be trusted. Compounding the issue, when it would simply drop out, garmin calculated the heart rate as zero when it wasn’t reading which skewed the average. A 10KM tempo run would show up with an average heart rate of 107, which is hardly accurate.

After reading a review by DCRainmaker (the go-to source for sports products testing) I decided to try the Scosche Rhythm + heart rate monitor which sports an optical heart rate monitor.

Scosche_RHYTHM_armband_heart_rate_monitor

This monitor fits on your arm, either on your forearm or bicep, and reads your heart rate by peering into your capillaries using three pulsing lights. Medical offices have used this technology for years by putting your fingertip into a little clamp. Those can read both HR and oxygen use, which is cool.

A quick note on reading heart rate – as unlikely as it seems that you could calculate HR by staring (through the skin) at your capillaries, keep in mind the way the old style monitors work. Contrary to the way a lot of people think they work, the chest straps do not “listen” to your heart beating like a stethoscope. The chest strap type monitor detects the electrical current from your heart and using that data it calculates your heart rate. It is no surprise that sweat and water and slight misplacement can cause the chest strap type of HRM to malfunction.

Here I am wearing the HRM on the forearm: Purple-103_3-18-49_tb14edit

You can see it there on my left forearm, the Garmin 910XT is mounted to the tops of the handlebars.

My experience with this HRM has been largely positive but not perfect. As far as the immediate problems I was trying to solve; inaccurate readings and dropping out, those problems went away when I started using this product in place of the Garmin HRM strap. Additionally, placing the strap on the arm is far more comfortable than around the chest. It is also much easier to adjust something around the arm than it is when it is under your shirt. It isn’t just more comfortable because it is in a more accessible area, the strap itself is made of a softer material.

There are a few things to keep in mind with this product. Many triathletes will put their tri kit on (uni style or top and bottom) with the chest strap zipped into place and then they put a wetsuit on over the whole kit. You cannot do this with the Scosche since it would be difficult to get in and out of the wetsuit with this product on. The Scosche is 1 meter water resistant, which is plenty, but even in a non-wetsuit swim I wouldn’t wear it on the arm for the swim. When I did Boulder 70.3, I put the Scosche in my tri top pocket for the swim, during T1 I removed it and slid it into place.

This unit is ANT+ and simultaneously bluetooth enabled. There is no switch for one or the other, the result is that the little thing is power hungry. Scosche says you will get 8 hours of battery out of it, I ran it for 8.5 hours without issue so their claims are either accurate to conservative. I suspect the battery life would be worse if you were collecting data by bluetooth as well as ANT+ instead of just ANT+. This capability, while battery draining, will allow you to connect the HRM to popular iPhone and Android apps and other devices which don’t support ANT+. I don’t use any of those, people that use things like MyFitnessPal and similar apps can sync their heart rate to the phone and and fitness watch at the same time.

I did encounter a problem early on which caused me to RMA the unit for a new one. The calorie and training effect metrics which display in Garmin Connect showed things which were way off. image

Here is the data from my Garmin from the bike leg of my 70.3, notice something off? I am a decent athlete but after two hours and forty minutes I can promise that I would have burned more calories than 90. I originally opened a ticket with Garmin who directed me to Scosche. Apparently the first revision of the software the units were shipped with used a defective calculation for Calories and Training Effect, as a result Garmin simply calculated the caloric burn as if I was at rest. I got a new unit and it works better, though the training effect still seems to be off.

It is unclear how this would effect a user who was not using a Garmin device, most people mentioning issues are Garmin owners so it may be that this was limited to Garmin and other users would not notice an issue with this at all.

I have one additional concern and that is the nice arm strap itself. It works as a sweat band similar to the bands that basketball players use to keep their hands free of the sweat from the upper arm. This means the strap gets soaked in salty sweat during every workout. I haven’t seen evidence of the material starting to fail or lose consistency but it is something I am going to watch.

Overall I like the transition from the chest strap to the arm band. HR readings are essentially accurate, pairing is easy and reliable, and re-charging the thing is not difficult. It isn’t perfect, no device is, but this is pretty darned good. I am comfortable recommending the product to anyone willing to spend $80 and hate chest straps.

Cadence and Heart Rate, a tale of two runs

Two things I don’t care about. Seriously, if you say ‘cadence’ to me while I am running I will be annoyed beyond belief. It would be like saying ‘watermelon’. I care about heart rate a little more because it can indicate if something is seriously wrong or if you can afford to push yourself a little harder.

To illustrate my point, I will use a tale of two runs. One run was an outdoor run and one was an indoor run. My outdoor run was baaaad according to Garmin, my cadence was too low and my heart rate was too high. Bad Cadence

Yellow is bad, green is good, according to Garmin. So I was in the green for only a little while.

My corresponding heart rate was also baaaaad, according to Garmin, somewhere around zone 8 or 9 (this is tongue and cheek).

Bad Heart Rate

Now on to my gooood run according to Garmin metrics. My cadence shows up mainly as green!

Good Cadence

The computer is much happier now. My heart rate is also better according to them. Good Heart Rate

Google “run cadence” and see the overwhelming amount of opinions on what the ideal run cadence should be. In fact, our coach insists that we pick up our cadence. I ask, however, “what scientific evidence have you that cadence matters?”. The honest answer is none. In fact, when it has been studied, it was found that coaching on run dynamics yields little benefit at all. There is a correlation that more efficient runners tend to have a higher cadence than less efficient runners. However, science is always conscience of the difference between causation and correlation. In other words, are the more efficient runners more efficient because of their cadence or is the cadence the result of something else, like higher levels of physical fitness.

So relax on the cadence, it will come (mine has gone up) as one becomes more fit.

On to the heart rate and “zone training”. The idea behind zone training is that your exertion can be measured in neat little boxes where you have a “fat burning zone” and an “anaerobic threshold zone”. heart-rate-zones1

This is why everyone and their mother wears a heart rate monitor now. When I was ripping off sub 7 minute miles in cross country I can’t remember my coach ever saying anything about heart rate zones.

Same question, “what science, have you, that backs up these findings”? There actually is quite a bit of science surrounding this (more than cadence) but, as always, it is much more nuanced than a simple box. The first nuance we have to be aware of is that at all times you are engaged in anaerobic respiration, (refer to earlier post) so it is disingenuous to make a zone called “anaerobic zone” as if it just kicks in at 160 bpm and your ATP production stops. My coach uses a term “lactate”, in reference to the time in which the amount of lactic acid produced by the cell’s fermentation process exceeds the cell’s ability to remove lactic acid from the cell.

The other disingenuous bit is the “fat burning zone”. There is no such thing. There is a zone that fat tends to be burned in, but that is more related to the fact that the average person can stay in that zone for a long time and therefore dip into their fat reserves for energy. A trained athlete will burn fat at any “zone” provided they are exercising long enough to dip into their fat stores. This is why sprinters and distance runners are both quite lean, even though their training hits much different intensities over different time intervals, they are both burning fat…and probably eating better than average.

I actually engage in a bit of zone training, I look at my watch to make sure I am not getting an abnormally high heart rate – but I don’t split hairs between 145 and 155, or even 145 and 159. At 160 I start paying attention, if the pace is good and and high and I feel OK, I let it ride out.

So back to my two ones, one run Garmin tells me I “overreached” and the other was “highly improving”. One was a 6.1 mile outdoor run on varied terrain, up and down hills, with a strong uphill headwind for the first mile. The other was a 3.2 mile treadmill run. Garmin says the treadmill run was the better one. I disagree, while my heart rate was high, the run was designed to make me run at a higher tempo than normal. More importantly, I was not sore at all the next day even though according to the chart I should have been in full bore lactic acid overload.

I don’t mean to bash coaching recommendations based on zone and cadence, in fact I use those metrics myself to evaluate my progress. The exercise industry is FULL of claims about certain products and techniques where very few have been tested to a scientific standard. More importantly, we should not reduce exercise to a video game (keep your heart rate here, keep your cadence here….now you are winning!). Consistency in training is king.

Respiration, Glycogen, and any time anyone ever says “Anaerobic Threshold”

Having taken a couple of advanced microbiology classes in an ill-fated attempt to get into veterinary school, I sometimes have a skeptical attitude towards trainers and their understanding of biology. So, for a brief moment, I will put on my science professor hat and I will step us through some of this jargon.

Firstly, we have to understand why we breathe. Oddly enough, this is never explained by any training material but it has an important relationship to exercise. Oxygen, as we all know, is needed to us to live. Few people can pinpoint exactly why that is. In order to understand that, we have to get microscopic. In order to for cells to do their jobs, they need to go through a process called cellular respiration. In this process (you might have some nightmares about terms like the “Krebs Cycle”) cells generate a substance called adenosine tri phosphate or simply ATP. ATP is what gives the cells the ability to do their respective jobs. The waste product produced by respiration (more properly, the electron transport chain) is an electron in the form of a carbon atom which is removed from the cell via oxygen. Now your brain is firing away connecting the dots of knowledge that you already had – you breath out carbon dioxide.

You might think – “Well that is all well and good, but what if I hold my breath?” Which is an excellent question because you can stay conscious holding your breath even after your body is starting to be deprived of Oxygen. Of course, the body has another way of producing energy. Fermentation, broadly, does the same thing except it produces lactate as a waste product which is removed from cells using completely different system.

Aerobic processes produce far more ATP than fermentation. However, it is not perfect. Some cells do not have mitochondria and therefore will never participate in aerobic respiration. The production of ATP through the electron transport chain, while efficient, isn’t exactly like a factory where it can simply work faster. If the body exceeds the ATP needs of aerobic respiration or if the body rapidly requires the use of more ATP, then fermentation is the only option the body has.

Now for the “anaerobic threshold” which is on everyone’s’ tongue. Put simply, untrained athletes require much more ATP than a trained athlete does, as a result, for the same amount of work (say, running a 5K in 30 minutes) an untrained athlete’s body will resort to using fermentation for making energy for the same amount of work. The resulting soreness in the untrained athlete is the buildup of lactic acid.

Keep in mind that I drastically simplified this process so it can fit into a blog length post. I use the word “fermentation” instead of “anaerobic” because technically anaerobic means not in the presence of oxygen. Although it is splitting hairs, fermentation and ATP production using oxygen happens at the same time in the cell. Therefore oxygen is present and is not technically anaerobic. Fermentation is the chemical process used to produce acid from sugar whether oxygen is present or not.