Am I a runner or a biker? Part 1

Am I a runner or a biker? Part 1

This article is about the experiences of author Hans van Dijk, who was suddenly confronted with a knee injury on May 4th, 2019. Most readers will know Hans as a lifelong runner and author of The Secret of Running. Hans started running on August 3rd, 1980, the day after Dutch runner Gerard Nijboer won the silver medal in the Marathon at the Moscow Olympics. Hans can therefore indeed be called a lifelong runner with almost 40 years of experience.

Lifelong, until May 4th, 2019. The knee injury was the beginning of a long road along many doctors and medical specialists in various hospitals. Unfortunately, the conclusion was that the cartilage in the knee is severely damaged with little hope of treatment and recovery. What now?

The advice was to start cycling as an alternative training. Hans initially did not like the idea, but from October 2019, he reluctantly started as idleness is not his thing. Initially, he started on his old grandpa bike (including the child seat for his granddaughter), but soon he bought an MTB with a power meter (the Garmin Vector 3, which measures left and right separately, so you can see if both legs produce the same power ).

The nice thing about a bicycle with a power meter is that your running watch (Hans uses a Garmin Forerunner 935 watch) then displays your fitness daily in the form of your cycling VO2 max (which is calculated from the measured power). And the results of Hans’s daily bicycle training sessions were very encouraging and even quite spectacular. His VO2 max continuously increased to a value of 61 ml/kg/min (see the figure). It was 6 years ago that he reached such a high value in running. In addition, Hans has only been cycling for half a year and has run for 40 years. Does this mean that he is actually better in cycling than in running? It’s starting to look a bit like it. The future will tell.

Hans’ development of cycling VO2 max in the last six months

In this article, we will take a closer look at the significance of the VO2 max as a measure of the performance in running and cycling. In a subsequent article we will discuss the power in watts, as measured by Stryd when running and by power meters like the Garmin Vector 3 when cycling. Then we will also show how to calculate how fast you can run and bike with a certain power in Watts.

What is the VO2 max?

As early as 1923, the English physiologist A.V. Hill discovered that the oxygen consumption of runners increased with increasing speed to a maximum value, which could only be sustained briefly. He therefore argued that the running performance is primarily dependent on the oxygen uptake capability of the cardiovascular system and called this maximum capability the VO2 max. Many researchers have since confirmed that the VO2 max is indeed the most important parameter for the performance in running, cycling and other endurance sports .

The VO2 max is defined as the maximum volume (V) of oxygen gas (O2) that the human body can absorb per unit of time during physical exertion, measured at sea level. The VO2 max is expressed in the number of milliliters of oxygen per kilogram of body weight per minute (ml O2/kg/min).

How is the VO2 max determined?

The VO2 max is classically determined in a physiological laboratory by measuring oxygen intake and oxygen emissions during prolonged and increasing intensive physical exertion. The VO2 max is reached when the amount of oxygen absorbed does not increase anymore, despite an increasing effort. Such a measurement usually takes place on a treadmill or a bicycle ergometer. It should be carried out under medical supervision, for example in a Sports Medical Advice Center.

Hans had such an investigation carried out several times. The photo shows Hans, the treadmill, the respiration measurement equipment and the ECG measurement.

Hans during a VO2 max test on the treadmill with continuous ECG-monitoring and breathing gas analysis with sports doctor Bernard te Boekhorst of SMA Midden Nederland.

With modern running watches like Garmin, Polar, etc., you get a daily update of your VO2 max based on your performance during training and races. This is perfect to see the impact of your workouts on your fitness and determining if you’re in shape.

What does the VO2 max depend on?

The VO2 max appears to mainly depend on:

  • Talent (if you want to be a great runner, choose your parents carefully)
  • Gender (men have an approximately 10-15% higher VO2 max than women)
  • Age (the VO2 max decreases by approximately 0.5-1.0% per year above the age of 35)
  • Training (the VO2 max can increase about 5-25% through training)
  • Body weight (the VO2 max is inversely proportional to the body weight; losing weight leads to a higher VO2 max)

The VO2 max of the world best is around 90 ml/kg/min, as you can read in our books The Secret of Running and The Secret of Cycling. It should be noted that in exceptional cases even higher values ​​have been measured, such as with the Norwegian Oskar Svendsen (up to 96.4!), But in those cases a lower efficiency limits the performance. For ordinary mortals, the table below gives a picture. Normal values ​​for young men are 40-45 and for young women 30-35 ml/kg/min. Even with the most fanatical training, ordinary people can never reach the values ​​of the world leaders.

How fast can you run with a certain VO2 max?

In principle, your running speed is directly proportional to your VO2 max. In practice, the weather conditions, the distance and the course will also have an impact. All these factors are covered in our books and on our calculators at our website. The race time at various classic distances is shown in the table below (which applies to ideal conditions).

The table shows that with a VO2 max of 60 ml/kg/min you can run a time of 18:30 on the 5K and 38:50 on the 10K. In 2013 Hans ran a little faster at the age of 59 (17:43 on the 5K and 36:25 on the 10K), so his VO2 max was slightly higher than 60. However, his fitness and shape has deteriorated somewhat in recent years and last year his running VO2 max fluctuated between 58 and 60. So, it Is quite remarkable that his cycling VO2 max is now 61 after only half a year of bike training. All the more since Hans will soon be celebrating his 66th birthday!

How fast can you bike with a certain VO2 max?

More factors than just VO2 max play a role in cycling. Your bicycle to start with. On a race bike, both rolling resistance and air resistance are a lot lower, so you can bike much faster with the same VO2 max than with an MTB or city bike. The wind also plays a much greater role than with running. Also, the course plays a major role. In principle, your uphill speed is directly proportional to your VO2 max. On the flat, however, the product of your VO2 max and your body weight determines your speed. This is easier to explain using cycling power in Watts. In the article of next week we will show how fast you can bike with a certain power, depending on your bicycle, the weather and the course.

Which is more fun: running or cycling?

Well, to each his own of course. As far as Hans is concerned, there is still nothing to top running, wonderfully jogging on small trails through the woods and in nature. And he also has warm memories of the friendly atmosphere at the track and road races and the Masters championships. He still hopes that someday in the future he will be able to run again without injury.

But cycling also has its charms: you discover other trails (also beautiful) and your range is of course a lot bigger. This way you can explore the further surroundings, all the more so since you can maintain cycling for much longer. Cycling takes a lot more time, not only for the training itself, but also for dressing and maintaining the bicycle. Also, cycling is more of a hassle with flat tires, replacing chains and sprockets and the many material options. Finally, cycling is a lot more dangerous. That is also the reason why Hans sticks to his MTB and does not buy a fast racing bike.

But once you are on your bike and enjoy biking through quiet paths, it is just like enjoying running again. After the training, Hans is much less tired, even if he trains with the same heart rate as when running. It also seems that you can train your anaerobic system better with cycling, as Hans reaches higher maximum heart rate values ​​on hills than with running.

Meanwhile, Ron has also bought an MTB so he can join Hans on Sunday mornings with beautiful cycling trips in the Dutch countryside. Who would have thought this of those 2 lifelong runners?

Our book ‘The Secret of Running’ is for sale in our webshop. Also available in German as ‘Das Geheimnis des Laufens’, and in Italian as ‘Manuale completo della corsa’.