The physiology of a champion (part 1)

By Thomas Bonne

I’ve long been wanting to do a piece on Annika’s physiology. My name is Thomas and Annika is my better half. I’ve been riding since the early 90’s but was never as successful as Annika. So I had to come up with something else to do. That something else turned out to be studying which led to a phd-position at the University of Copenhagen with Nikolai Nordsborg. The guy that got me into all this studying and research however is Carsten Lundby. A professor at the University of Zürich, my co-supervisor, a keen athlete and good friend. Today I work as a coach for some talented riders (Simon Andreassen, Sebastian Fini and Andreas Kron among others) and am very much influenced by the time I’ve spend with both Nikolai and Carsten. So what better way to spend some summer time than to persuade your world champion girlfriend to do some lab-testing! You have to remember I’m biased regarding Annika but her story and way into the world of cycling is rather unique.

I met Annika in 2008. Back then she started riding in my local club when she was not sitting with her head in the books at the university. Aged 24 at that time it was definitely not in the cards that she would end up as a multiple world champion. Especially not since she had no history of doing sports at an elite level. Sure, she’d been active most of her life. Did the occasional adventure race or duathlon, often skied as a child and took a year out to become a ski instructor before going to university. But she never did any structured training or aimed for any athletic accomplishments until she got hooked on mountain biking.

During her first competitive season (2008) it became clear that she had an extraordinary physique. She placed 3^rd at the nationals and won a larger XCM race in Sweden (Bockstensturen) by just “fooling around” with 3-4 weekly training sessions with the local club. In 2009 she won her first Bundesliga race ahead of Irina Kalentieva and Alexandra Engen and in 2010 she took home her first world championship medal by placing 3^rd at the XCM Worlds in St. Wendel. 2011 could be considered her breakthrough season with a 2^nd at the XCO World Cup in Dalby Forrest and later a 3^rd in Windham. In Montebelluna, Italy she became XCM World Champion for the first time. The next two seasons proved difficult for Annika despite winning the XCM Worlds again in 2012 and some decent results like a 6^th at the TT Worlds in 2013. She managed to work out the quirks in 2014, won the XCM title for a 3^rd time and was never outside the top 11 in the XCO World Cup. The rest is history, as they say.

Getting started as an elite endurance athlete at the age of 24 is very rare (at least if you want to be successful). In a two-part blog series I’d like to share some of the work that Annika (and those around her) is putting in on a daily basis as well as her physiological characteristics rendering her to perform at this level. Despite starting at a relatively late age. We’ll start with latter. For some it’s going to be trivial, for others a bunch of gibberish. Feel free to leave a comment if you want to know anything more detailed or have clarifying questions. It’s going to be one of the longer posts on this site so grab a coffee or maybe just start with the video to see if you’ll be intrigued.

The fuel driven engine is often used as an analogy to the human body. In order to produce power an engine requires to things: fuel and oxygen (O₂). The same goes for the body. Our fuel being carbohydrate (stored as glycogen) and fat (okay, protein and other compounds can also be used as a fuel source but for now let’s just keep it simple). In the muscles the fuel is being processed along with O₂ to produce the energy needed for muscle contraction. Essentially what this means is that as you increase your speed or power on the bike the demand for O₂ increases as well. That’s why maximal oxygen uptake (VO_2max) is an often used performance parameter in both scientific studies and evaluation of athletic performance. If you follow or are active in any endurance sport, chances are that you’ve heard or often hear the term VO_2max being mentioned. Maybe you’ve even done a VO_2max test. If so, you’ll get a chance to compare yourself with the world’s best in the following, where we’ll take a look at what it requires to have a high VO_2max. If you’re interested in this stuff I recommend this paper by Carsten Lundby and Paul Robach which is free for download. It will also provide some interesting numbers for comparison further down this page. The entire paper is worth a read if this stuff interests you but for convenience I’ve put in a table from the paper here. I’ve also taken the liberty of framing the values from female medalist for comparison with our own subject.

Haemoglobin mass, Blood Volume & Maximal Cardiac output.

But let’s start with another important characteristic for endurance athletes. The blood. Both the total volume and the O₂ carrying capacity areof importance for endurance performance. Keep in mind that it’s all about getting the O₂ to the muscles. As O₂ enters the blood through the lungs it binds to a molecule in the  red blood cells called haemoglobin. So obviously, the higher amount of haemoglobin you have the greater the potential for O₂ carrying capacity is and thereby producing more power, running faster etc. We measured Annika’s total haemoglobin mass (Hb_mass) by a CO-rebreathing method using a new machine developed by Carsten. I’m not going to go into detail with the method here but the new machine is designed to minimize measurement error and increase subject comfort. Annika had a Hb_mass of 787 g which is 12.34 g/kg (again – the relative numbers gives a measure more usable when comparing individuals). This puts her right up among several Olympic XC-skiing medalists. There’s no doubt that she has high values for a woman.

In addition to a high Hb_mass it’s also important to have a high total blood volume (BV). Essentially the heart is a pump. The O₂ that enters the blood through your lungs need to be delivered to the working muscles and the heart is responsible for delivering all that precious O₂-filled blood to muscles and organs. Exactly how much blood the heart is able to deliver is measured in liters per minute (l/min) and called cardiac output (Q – and as with VO_2max the maximal Q is denoted Q_max). The magnitude of your Q_max is to a large extend determined by BV. As Carsten explains in the video this is very important for performing well as an endurance athlete. In 2012 I did a study at Carsten’s lab in Zürich that illustrates this point. The results are depicted in the picture below. Solid lines are data from each study subject with dotted lines being the average for all subjects. A group of subjects exercised for six weeks. Before the exercise intervention started we measured their BV (fig. A, Pre). At the same time, we determined their Q_max (fig. B, Pre) and had them do a VO_2max test (fig. C, Pre). At the end of six weeks exercise we measured everything again and found that BV was increased (fig. A, Post), Q_max was higher (fig. B, Post) and VO_2max had increased too (fig. C, Post). To test the hypothesis that BV was important for Q_max and thus for VO_2max we removed the amount blood each subject had gained as a result of six weeks’ exercise (Phlebotomy). The result was a completely reversal of Q_max and VO_2max to baseline level.

The take home message is that if you want to be an elite endurance athlete it requires high Hb_mass, BV and Q_max. Which is exactly what you can extract from table 1.

Back to our subject at hand – Annika. We’ve already learned that her Hb_mass is high. What about her BV? 5.7 l in total. A quick look at the table again reveals that it is a really high value for a woman. When she rides close to her maximal aerobic capacity her heart pumps out (Q_max) approximately 30 l/min. To get an idea of how much that actually is take a look at the video. Although athletes at the level of Annika are not working at Q_max for the entirety of their competition it’s not hard to imagine how much work the heart is doing throughout an XC-race. Simply fascinating!

VO_2max

VO_2max is measured as ml of O₂ consumed per minute (ml/min). However, as the muscles is the tissue using/needing the O₂ there is of course a difference in how many ml/min of O₂ an 80 kg male cross-country skier can take up compared to a 60 kg female cyclist. To be able to compare the two we need to look at VO_2max in relative terms: ml/min/kg. Remember that although an 80 kg male cross-country skier has a higher VO_2max he also has a lot more weight to carry around. Still, the men have higher values compared to women. Athletes in sports that involve a large muscle mass (e.g. XC-skiing where you use the entire body) tend to display the highest values whereas endurance athletes using less muscle mass (e.g. swimmers who are mostly using the upper body) areoften somewhat lower on the scale.

With a high Hb_mass, BV and Q_max we already suspect Annika to have a high VO_2max. The first measurement of Annika’s VO_2max we have is from 2008. Back then the unknown girl fooling around with the local club raised eyebrows at the Copenhagen Muscle Research Center with a VO_2max of 4485 ml/min which back then was 68.5 ml/min/kg in relative terms. Annika’s absolute VO_2max has only changed slightly throughout the past eight years. Earlier this year we measured (over a 30 second period) a VO2max of 4595 ml/min. At that time her weight was 63 kg which corresponds to a relative VO_2max of 73 ml/min/kg. We tested this at a time where she probably even wasn’t at her best but regardless of this the values will not differ that much.

With Annika starting her sporting career late compared to her peers and with a relatively little change in absolute VO_2max the interesting question is how much of this is trainable and how much is genetically disposed? Again, I can only refer to the paper by Lundby and Robach for an easy to read (and interesting) discussion on this topic.   

Let’s sum up the results from testing our champion:

If you compare these values to those in table 1 you’ll notice that Annika is right up there with the XC-skiers. Reportedly these are not the highest values ever measured for women endurance athletes. It is clear though that Annika possess a physiology that would make her successful in almost any endurance sport given she could require the technical and tactical skill of the discipline. The fact that she started as a competitive athlete at the age of 24 and became as successful as she is today being a testament to that. Her choice of parents was surely the right one as witnessed by her first VO_2max test. In fact, take a look at her VO_2max as it has been measured throughout the years.

Notice that in absolute terms Annika’s’ VO_2max does not change significantly (once again I encourage you to read the paper by Lundby and Robach for a discussion on this topic). However, it has taken eight years to reach the performances she’s delivered this season. To this there is likely multiple explanations. One being an increased power/efficiency. Now, some of you reading this are probably wondering how much power Annika actually produces as a result of the above. Keep an eye out for part two where I’ll get much more hands on with the training, the power Annika is able to produce on the bike and how we use it in training. In reality Annika hates testing. To her it is another form of racing (when she really wants some time off from racing). In part II I’ll also give some insight, or rather opinion, on the difference between XC and XCM and why it works perfectly for Annika to do both.