Another exciting training arcticle prepared by Stephanie Rees. This article examines the stress system in the context of XC ski racing. See the training archives for other articles. Read on... (Click below)

Imagine yourself in the following situation: there are five minutes until the gun goes off and you’re expected to hustle to victory. Several thoughts may race through your head at that moment.

These might include:

- Maybe I shouldn’t have had that second sausage and/or donut.
- My skis are really slippy... too bad it’s a classic race today.
- Did I leave my waxing iron turned on? Will it burn down the chalet?
- Maybe.. just maybe.. I should have trained more this year.
- Wow! Those 12 year-olds look fast.
- Now, do I have 10 or 15 minutes to go before my start?
- I don’t remember enjoying this event last year.
- Help!

The point of this incomplete list of pre-race thoughts is that skiers have to deal with a lot of stress before the start of a race. But what makes such a list interesting (and complicated) is that every individual skier has a different list of concerns before a race. For example, I personally do not eat sausages and/or donuts before a race, but I do know skiers who do (and you know who you are!). Thus, I do not get stressed about sausages and/or donuts. Because psychological stress is such an individual thing, it makes it very difficult to generalize about what to do about stress before a race. However, there is an aspect of stress and skiing that we can talk about that will apply to some extent to everyone; that is the physical stress that is incurred during the race.

Recently, I came across an interesting article about long-distance skiing and the effects of stress hormones (Vaananen, et al., 2004). Stress hormones are released in response to both acute psychological and physical stressors (see Herman, et al., 1997 for review). In response to a stressor, it is important for an increase in stress hormones to occur so that the body can cope and adapt to stress. For example, when you meet a bear while out training (you out training, not the bear.. or maybe the bear out training.. either way… ), an upsurge in stress hormones allows for more blood and energy to be directed to your muscles and for increased respiration and a higher heart rate. This permits you to either fight the bear or flee away from the bear. However, long-term exposure to increased stress hormones can have severe effects, such as detriments to learning and memory, a suppressed immune system, impaired digestion, fatigue, hypertension, etc. (see Sapolsky, 1992 for review). Because stress hormones, regardless of their cause, have such effects on several important systems, it is necessary to understand if long-distance ski racing can affect stress systems.

Published in the Journal of Sports Medicine and Physical Fitness, Finnish researchers Vannanen, Vasankarj, Mantysaari, & Vihko (2004) looked at changes in levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and cortisol after two days of skiing 50km (first day: 50 km classical technique; second day: 50 km skating technique). Due to the surprising similarity of this experiment to the program at the Keskinada (in terms of the distances and techniques), the results of this experiment provide interesting food for thought. Of interest for us in terms of stress is the hormone cortisol. In this experiment, several blood samples were collected over the two days of skiing. On the first day, the first sample was collected immediately prior to the first 50 km while the second sample was collected immediately following the 50 km. On the second day, the same procedure was repeated. The final blood sample was collected one week after the second 50 km as an example of long-term recovery. The power of this method is that each skier can serve as his own comparison group as changes in pre- and post-test levels can be compared within individual skiers. After 50 km of classical skiing, an increase in cortisol was seen on day one. A similar pattern was seen after 50 km of skate skiing on day two. Interestingly, pre-ski levels of cortisol on day two were lower than those on day one, suggesting that the first day of skiing, despite being stressful, suppressed cortisol levels before the next session of skiing on day two. Although not addressed by the researchers (Vaananen, et al., 2004), this may be due to decreased anticipatory stress (i.e. decreased psychological stress because you’ve been through it all the day before) before the second ski session or due to a regulatory aspect of the stress system. This regulatory aspect is used to maintain normal levels of stress hormones through a built-in negative feedback system that returns stress hormone levels to normal after exposure to stress. If functioning normally, negative feedback prevents the effects of long-term exposure to high levels of stress hormones that were listed above. Alternatively, the skiers studied in this experiment may be more stressed about an upcoming classic race (first day) than an upcoming skating race (second day)!

Although I have not (yet!) experienced racing 50 km for two days in a row, I can imagine that it produces much fatigue and soreness. And I can imagine, that the fatigue and soreness can last for a while (how long mostly likely depends on how much training a skier has completed in preparation for the big race). The good news, however, is that Vaananen, et al. (2004) did not find any lasting effects of skiing two 50kms over two days on stress hormone levels. One week later, cortisol levels did not differ from initial baseline levels prior to skiing 50 kms. So, you’re recovered for the next week’s racing! Yea! In summary, in terms of physical stress, there is an increase in stress hormones after a long-distance race (not surprising!), but interestingly, there is a significant decrease in stress hormones on the following day during the pre-race period. Why this occurs is unclear. The good news is that it seems that the effects of long-distance racing do not have long-term effects on the stress system, at least in terms of physical stress. However, the not-so-good news is that despite this knowledge, we haven’t dealt with our psychological stressors yet. However, maybe next time we will!