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stroke [2025/12/23 13:57] pstureavley |
stroke [2026/10/01 19:54] (current) pstureavley |
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| Photo: from Adam Van Koeverden [[https://youtu.be/i81C5xEU_yM|video]] | Photo: from Adam Van Koeverden [[https://youtu.be/i81C5xEU_yM|video]] | ||
| - | {{ :technique:avk_technique.jpg?direct&550x223 |avk_technique.jpg}}</WRAP> | + | [[https://surfski.wiki/lib/exe/fetch.php?media=technique:avk_technique.jpg|{{ :technique:avk_technique.jpg?direct&550x223 |avk_technique.jpg}}]]</WRAP> |
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| * Key to a powerful stroke is power at the beginning of the stroke. | * Key to a powerful stroke is power at the beginning of the stroke. | ||
| - | * <del>Keep lower arm straight or almost straight. Imagine you are pivoting around the spot with the blade stationary in the water; boat moves past the blade, not vice a versa.</del> This advice is a bit off… You do not want to be bending your power side arm excessively or arm paddling (trying to use your biceps too much instead of rotating (but the biceps are definitely engaged)), but as soon as power starts to be applied for most paddlers there is a slight bit of bend in the arm. Max power from the legs and rotation cannot be fully applied by most paddlers with an arm that stays completely straight. Also you want the wing blade to follow its natural drift outward while staying perpendicular to your boat. If you force a completely straight arm throughout your power phase, are you still letting your blade follow its most efficient path? And how smoothly can you make a rapid transition between completely straight and the fairly bent recovery position? The explanation and visual from Ivan Lawler's video ([[https://youtu.be/CL_h6lLaNMM|Day Six Lower Arm]]) is better than we can explain with text. He calls this slight arm bend "somewhere between straight and (//what he calls//) broken". This arm bend can be a little hard to see in paddler videos between the catch and exit, but if you slow down technique videos (e.g. with youtube playback speed settings) you should be able to see it more easily and how quickly the transition occurs between this slight bend (where Mr. Lawler says you are basically "holding on" with the lower arm) during power application and when the lower arm rapidly bends during recovery. | + | * <del>Keep lower arm straight or almost straight. Imagine you are pivoting around the spot with the blade stationary in the water; boat moves past the blade, not vice a versa.</del> This advice is a bit off… You do not want to be bending your power side arm excessively or arm paddling (trying to use your biceps too much instead of rotating (but the biceps are definitely engaged)), but as soon as power starts to be applied for most paddlers there is a slight bit of bend in the arm. Max power from the legs and rotation cannot be fully applied by most paddlers with an arm that stays completely straight. Also you want the wing blade to follow its natural drift outward while staying perpendicular to your boat. If you force a completely straight arm throughout your power phase, are you still letting your blade follow its most efficient path? And how smoothly can you make a rapid transition between completely straight and the fairly bent recovery position? The explanation and visual from Ivan Lawler's video ([[https://youtu.be/CL_h6lLaNMM|Day Six Lower Arm]]) is better than we can explain with text. He calls this slight arm bend "somewhere between straight and (//what he calls//) broken". This arm bend can be a little hard to see in paddler videos between the catch and exit, but if you slow down technique videos (e.g. with youtube playback speed settings) you should be able to see it more easily and how quickly the transition occurs between this slight bend (where Mr. Lawler says you are basically "holding on" with the lower arm) during power application and when the lower arm rapidly bends during recovery. Also watch [[https://www.facebook.com/reel/1214198593979015|paddle2fitness]] (facebook reel) |
| * When driving heel down hold toes back - don't tap your steering with each stroke. | * When driving heel down hold toes back - don't tap your steering with each stroke. | ||
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| - | ===== Ventilation ===== | + | ===== Cavitation (or is it Ventilation?) ===== |
| <WRAP indent> | <WRAP indent> | ||
| - | From [[https://guillemot-kayaks.com/how-paddle-works#:~:text=Ventilation is what you call,average kayaker creates is ventilation.|Guillemot Kayaks]]: | + | From [[https://guillemot-kayaks.com/how-paddle-works#:~:text=Ventilation is what you call,average kayaker creates is ventilation.|Guillemot Kayaks]] (with a couple of notes from our wiki editors): |
| - | **"Ventilation** is what you call it when the paddle sucks air down the back of the blade. Many people **call it cavitation**, but that is when a propellor spins so fast that it creates a vacuum behind the blade (//Ed. Note: And when imperfections in a blade contribute to vacuum formation//). Neither is any good, but **what your average kayaker creates is ventilation**. The reason it is no good is you are moving air instead of water. Air weighs a lot less than water and if there is air behind your paddle instead of water the mass of water you are moving is decreased and thus creating the same momentum requires you expend more energy. | + | <WRAP center round info 95%> \\ "**Ventilation** is what you call it when the paddle sucks air down the back of the blade. Many people call it **cavitation**, but that is when a propellor spins (Ed. or any object moving fast enough in water) so fast that it creates a vacuum behind the blade (Ed. Note: this is not really vacuum formation, but rather the formation of low pressure space behind the moving object or blade that causes water vaporization). Neither ventilation nor cavitation would help your paddling, but **what your average kayaker creates is ventilation**. The reason it is no good is you are moving air instead of water. Air weighs a lot less than water and if there is air behind your paddle instead of water the mass of water you are moving is decreased and thus creating the same momentum requires you expend more energy. |
| - | There are two ways of creating ventilation. One is by bringing the air down with the blade as you insert it into the water. The other is to pull air down the back of the paddle as you apply power. Both can be avoided by being sure your blade is fully submerged before applying power (//Ed. We believe that everyone starts to apply some power before their blades are completely submerged, but the idea is to have your paddle mostly submerged by the time you start to apply the peak of your power//). A clean entry will not bring down much air and the small area near the top of the blade is less likely to ventilate." | + | There are **two ways of creating ventilation**. One is by bringing the** air down with the blade as you insert it into the water**. The other is to pull **air down the back of the paddle as you apply power**. Both can be avoided by being sure your blade is fully submerged before applying power (Ed. We believe that everyone starts to apply some power before their blades are completely submerged, but the idea is to have your paddle mostly submerged by the time you start to apply the peak of your power). **A clean entry will not bring down much air** and the small area near the top of the blade is less likely to ventilate." \\ </WRAP> |
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| + | **More on Cavitation **- imperfections in a blade also contribute to cavitation which typically occurs with objects that have some kind of edge (does not occur with spheres). Previously cavitation was thought to only be caused by high speed movement, but it has subsequently been experimentally observed with objects moving as slow as 1 meter per second. So theoretically it may be possible for a paddle blade to cause cavitation, but **we currently believe that ventilation is the primary issue that paddlers are dealing with and should try to minimize**. | ||
| </WRAP> | </WRAP> | ||
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| - **Non Power/Back Side of Blade Scull (more horizontal paddle position)** | - **Non Power/Back Side of Blade Scull (more horizontal paddle position)** | ||
| - Use this as an active support stroke while your boat is stationary - providing continuous support and extra stability and avoiding paddle dive | - Use this as an active support stroke while your boat is stationary - providing continuous support and extra stability and avoiding paddle dive | ||
| - | - This is a scull pretty much using your low brace position (you can position the paddle more perpendicular to the boat if you want more leverage) | + | - This is a scull pretty much using your low brace position (you can position the paddle more perpendicular to the boat (straight out from the boat) if you want more leverage) |
| - angle the leading edge (edge leading whichever direction the blade is currently going toward) of your sculling blade slightly upward so the your sculling blade will always stay on the surface and not dive. | - angle the leading edge (edge leading whichever direction the blade is currently going toward) of your sculling blade slightly upward so the your sculling blade will always stay on the surface and not dive. | ||
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| <WRAP centeralign> | <WRAP centeralign> | ||
| - | {{:technique:preswim.jpg?direct&400x312|preswim.jpg}} | + | [[https://surfski.wiki/lib/exe/fetch.php?media=technique:preswim.jpg|{{:technique:preswim.jpg?direct&400x312|preswim.jpg}}]] |
| **Pre-swim paddle dive**</WRAP> | **Pre-swim paddle dive**</WRAP> | ||
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| + | <font inherit/inherit;;#ecf0f1;;inherit>This page has been accessed for: Today {{counter|today}} / Yesterday: {{counter|yesterday}} Until now: {{counter|total}}</font> | ||
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| + | ~~NOCACHE~~ | ||
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