Thank you for your detailed reply. It's really great to learn details of these movements. The direction (and duration) of push brings some more questions. In speed-skating, the direction of the push is 90 degrees to the direction of the travel (ie, straight to the side) and into into the ice (to maintain the maximum contact pressure). You suggest pushing at a larger angle and at various degrees of force (based on how far away your leg is). Doesn't this cause your weight to shift back and also limit how much force you can actually apply? You are moving forward and pushing back at the same time, so this inevitably causes your weight to shift back. Are there any leg push force graphs in scientific literature?
Thanks for this question, Ales! This is possible to misunderstand! It is important to know that also on skis we kick 90 degrees on the ski, but the ski will be angled at a different degree depending on speed and terrain (in relation to the skiing direction). However, when speed skaters went from skates to clap skates the main difference in the technique was the practical direction of the kick, and especially in the curves. The clap skate did also increase both the duration time of the kick (it become longer) and the length of the kick. We in Cross-Country skiing have always had "clap skates" even if wery many skiers and coaches are acting like we don't have them, meaning that they focus on clicking sideways and through the heal. If you kick sideways through the heal you will be sitting and always struggle with the important forward fall in the whole body. To avoid loss of force when you are moving forward you must have a kick that brings you forward not just falling forward. Kick so you glide forward on the next ski (try whiteout the poles). To the last question, I haven't seen this done in cross country skiing, however, the best research is done in speed skating, you can also log for biomechanics in cross-country skiing and Stefan Lindinger from late 1990 or early 2000.
@@cross-countryskiingper-yvi9028 when coming up with the unpersönlich body, from the crunch, then most top athletes have a straight lower back, but I tend to have too much curve, lordosis, in my lower back..
Two questions: 1. How far do you keep pushing with a leg? It seems that the further away you push the less force you can apply. When your leg is almost straight, there's very little force. 2. When push off with your leg, is it better to push off with maximum force quickly, or is it better to try to apply force over longer period of time?
Hello Ales! Thank you for your question. You must kick all the way out to a complete extended hip, knee, and ankle joint, if not you will reduce the effect on the snow. Of course, the force production is small at the end of a kick due to the high speed forward and speed of the muscle contraction. All good movements are accelerated, slow in the start (even with a negative speed, eccentric start, the stretch -shortening cycle), and increasing speed joint by joint. This relation between force, contraction speed and effect are described and investigated by A-V Hill already early in the 1930 years.
The second question the force production is a product of force x time or force x cycle length (cm) and the answer will always be a combination of these two. However, we know that high force over a short kick is associated with a high skiing frequency. And we also know from science that when we are skiing in a competition the frequency is the same for skiers at different performance level and body height, and the cycle length is dividing fast skies from slow skiers. The skiing frequency 59-61strokes pr min, which also is your breathing frequency right before your anaerobic energy production becomes too high to continue the work for an extended period of time. Conclusively, the long cycle length is created when you apply force over a longer period, and that is both the most effective and economically.
The Compleat extension of the legs also serves the purpose of relaxation and micro brakes that opens the blood capillary and vessels so the oxygen supply to the muscles is optimal. Many skiers limit the strokes by not stretching completely, and this limits their endurance because the tensions in the muscles constrict the blood supply and limit the hearts stroke volume due to peripheral resistance. Peripheral resistance creates two main problems a) reduced mean transit time for the blood in the muscles which reduces this oxygen delivery to the muscles. b) Recoil through the blood vessels to the heart, which results in reduced stroke volume and increased heartrate (reduced minute volume) resulting in reduced delivery of oxygen to the muscles. The skiing technique can reduce the endurance in several ways; to high use of force in the technique (some muscles in the hip is already at 10-25% of one repetition max totally constricting the blood supply), skiing into deep positions, static muscle contractions and skiing whiteout micro breakes. Long explanation but I hope it makes sense?
La tecnica del "calcio"... e' un risultato della tecnica classica ?? Visto che è la "mamma " di tutti i gesti tecnici dello sci di Fondo ??.. Saluti dalla Italia (Verona) 🇮🇹
Thank you for your detailed reply. It's really great to learn details of these movements.
The direction (and duration) of push brings some more questions. In speed-skating, the direction of the push is 90 degrees to the direction of the travel (ie, straight to the side) and into into the ice (to maintain the maximum contact pressure).
You suggest pushing at a larger angle and at various degrees of force (based on how far away your leg is).
Doesn't this cause your weight to shift back and also limit how much force you can actually apply?
You are moving forward and pushing back at the same time, so this inevitably causes your weight
to shift back.
Are there any leg push force graphs in scientific literature?
Thanks for this question, Ales! This is possible to misunderstand! It is important to know that also on skis we kick 90 degrees on the ski, but the ski will be angled at a different degree depending on speed and terrain (in relation to the skiing direction). However, when speed skaters went from skates to clap skates the main difference in the technique was the practical direction of the kick, and especially in the curves. The clap skate did also increase both the duration time of the kick (it become longer) and the length of the kick. We in Cross-Country skiing have always had "clap skates" even if wery many skiers and coaches are acting like we don't have them, meaning that they focus on clicking sideways and through the heal. If you kick sideways through the heal you will be sitting and always struggle with the important forward fall in the whole body.
To avoid loss of force when you are moving forward you must have a kick that brings you forward not just falling forward. Kick so you glide forward on the next ski (try whiteout the poles).
To the last question, I haven't seen this done in cross country skiing, however, the best research is done in speed skating, you can also log for biomechanics in cross-country skiing and Stefan Lindinger from late 1990 or early 2000.
Whats the main mistake when there is to much hollow back when coming up from the Pole push? How to avoid it?
Hello Johannes and thanks for your question, however I am not shore what you mean by "to much hollow back"?
@@cross-countryskiingper-yvi9028 when coming up with the unpersönlich body, from the crunch, then most top athletes have a straight lower back, but I tend to have too much curve, lordosis, in my lower back..
Иверсен!!!
Two questions:
1. How far do you keep pushing with a leg?
It seems that the further away you push the less force you can apply. When your leg is almost straight,
there's very little force.
2. When push off with your leg, is it better to push off with maximum force quickly,
or is it better to try to apply force over longer period of time?
Hello Ales! Thank you for your question. You must kick all the way out to a complete extended hip, knee, and ankle joint, if not you will reduce the effect on the snow. Of course, the force production is small at the end of a kick due to the high speed forward and speed of the muscle contraction. All good movements are accelerated, slow in the start (even with a negative speed, eccentric start, the stretch -shortening cycle), and increasing speed joint by joint. This relation between force, contraction speed and effect are described and investigated by A-V Hill already early in the 1930 years.
The second question the force production is a product of force x time or force x cycle length (cm) and the answer will always be a combination of these two. However, we know that high force over a short kick is associated with a high skiing frequency. And we also know from science that when we are skiing in a competition the frequency is the same for skiers at different performance level and body height, and the cycle length is dividing fast skies from slow skiers. The skiing frequency 59-61strokes pr min, which also is your breathing frequency right before your anaerobic energy production becomes too high to continue the work for an extended period of time. Conclusively, the long cycle length is created when you apply force over a longer period, and that is both the most effective and economically.
The Compleat extension of the legs also serves the purpose of relaxation and micro brakes that opens the blood capillary and vessels so the oxygen supply to the muscles is optimal. Many skiers limit the strokes by not stretching completely, and this limits their endurance because the tensions in the muscles constrict the blood supply and limit the hearts stroke volume due to peripheral resistance. Peripheral resistance creates two main problems a) reduced mean transit time for the blood in the muscles which reduces this oxygen delivery to the muscles. b) Recoil through the blood vessels to the heart, which results in reduced stroke volume and increased heartrate (reduced minute volume) resulting in reduced delivery of oxygen to the muscles. The skiing technique can reduce the endurance in several ways; to high use of force in the technique (some muscles in the hip is already at 10-25% of one repetition max totally constricting the blood supply), skiing into deep positions, static muscle contractions and skiing whiteout micro breakes.
Long explanation but I hope it makes sense?
La tecnica del "calcio"... e' un risultato della tecnica classica ?? Visto che è la "mamma " di tutti i gesti tecnici dello sci di Fondo ??.. Saluti dalla Italia (Verona) 🇮🇹
:-)
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