In a short series of articles, FasterSkier will summarize the current discussion and research regarding the importance of oxygen uptake and anaerobic threshold for Cross-Country skiers.
Editor: Much of the material for this series of articles is based on articles in the Norwegian magazine SkiSport and in misc. Norwegian newspapers
A person’s maximal oxygen uptake (max VO2) is the best single indicator for predicting performance in Cross-Country skiing, and we find the highest max VO2 values among the best Cross-Country skiers. However, not much is separating the best skiers in the World. The best male Cross-Country skiers have values over 85 ml/kg/min, while the best female skiers have values above 70 ml/kg/min. There is a reason these athletes are best. To compete with lower oxygen uptake than your competitors is equal to driving a Volkswagen instead of a Mercedes. Luckily, it is fairly easy to become a Mercedes, as long as you train correctly. It is however also easy to spend lots of time training without getting close to converting your engine from a Volkswagen to a Mercedes.
 and good work-efficiency. The anaerobic threshold is the skier’s highest intensity (measured by heart rate or oxygen uptake values) where the production and removal of lactic acid is equal. This means that the AT is at the highest intensity where the skier is still able to ski for a relatively long time without “getting lacticâ€.</p>
<p>It is of course possible to improve the anaerobic threshold without improving the max VO2 value. This is best done by training at 85 — 90% of max heart rate (HR). However, the most efficient way of improving the AT is by improving the max VO2 — both values increase (or improve) together.</p>
<p><B>The important questions then become: How can we best increase the max VO2? Or, what limits the max VO2, such that we can improve this limiting factor?</B></p>
<p>International research the last few years have clearly shown that it is the heart’s per-minute stroke volume that limits the max VO2 in normal and well-trained individuals. The per-minute stroke volume is measured by how much blood the heart can pump to the working muscles during one (1) minute. This again consists of the individual’s maximal heart rate (MHR) and the amount of blood the heart can pump per contraction (stroke volume). The MHR is genetic, very individual and needs to be tested for each person to determine correct training intensity zones (the standard “220 minus age†test will not give you a good value). We have seen and tested 50 year olds with a MHR of 220, and 20 year olds with a MHR of 180. Since MHR can not be changed (it only decreases slowly with age), the conclusion is therefore that we need to improve the stroke volume to increase the pumping capacity of the heart.</p>
<p><I>How we improve the heart’s stroke volume, and therefore our max VO2 will be explained in the next article.</I></p>
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