‘Tis the season for winter sports, and that means many of the skiers I coach have disappeared to focus on their skill work. Those who stick around start asking for specific workouts to help with their performance. In one such sport, alpine skiing, power endurance tests like a ninety-second box jump test have been proposed as good methods of determining skiing performance in athletes. In a study published this month in the Journal of Strength and Conditioning Research, researchers looked at how a short HIIT-style training program affected power endurance in alpine skiers, although it’s a useful trait for skiers and non-skiers alike.
There will be a few diatribes in this article, but necessarily so. Some of this research is a bit ugly, but that doesn’t mean we can’t learn a thing or two from it. For example, the researchers called the high-intensity interval training program HIT, which is incorrect. HIT is actually something very different from what the researchers studied. That’s okay because this Swiss study perhaps suffered from a language barrier, but for the sake of clarity, I will refer to it as HIIT in this article.
The study is well designed, but the foundation of this research depends on a heap of assumptions, and some of them are dubious. The first assumption is that a ninety-second box jump test is a good test for judging ski performance. The second is that HIIT training will benefit box jump performance to an appreciable degree. The third assumption is that it’s useful for this increase in performance to happen in a very short time span.
A lot of these assumptions seem to come from the need to quantify things in a lab setting. In this study, the researchers used a box jump and only eight days of HIIT, probably because it made for a quick, publishable study. Studying actual skiing performance might have been better. Further, the idea was to improve performance by improving aerobic conditioning. While HIIT is okay for this purpose, it may have been better to compare HIIT to steady-state training, or at least see if longer training may be beneficial as well.
So let’s get to the results. After ten HIIT sessions over eight days, followed by a five-day rest, there was no change in performance on the box jump test. There was, however, a decent improvement in VO2 max during cycling, although it clearly didn’t transfer. Whether or not it would transfer to the actual sport of skiing – the only thing worth caring about here – is anyone’s guess. As one last note, the participants changed their box jump strategy for the final test, which could explain the difference in performance. This factor could also render the results more or less unimportant.
Earlier I mentioned that we can still learn from this study, so here are the lessons to take away. First, when looking at scientific studies, scrutinize them carefully and make sure you have a clear idea of the intended goals and underlying assumptions. Second, there are probably better ways to improve the aerobic component of your training, such as more steady-state training over a longer period of time. There’s no sense in rushing if you’re not getting results.
1. Micah Gross, et. al., “High intensity training and energy sources during 90-second box jump in junior alpine skiers,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000294
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