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#1
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Be relaxed
Be relaxed.
In any sport, if you want to last long and perform well, be relaxed. It is not enough emphasized in the "technique" threads IMHO. Is it achieved by a good technique or is it PART OF the technique ? The question remains. I guess that it's a feedback loop. A beginner will not be relaxed. You'll have to practice a lot and strech alike. My secret to race 50k/76k with decent results, without much training, is being relaxed. From time to time, check your entire body and look for unnecessary contracted muscles and relax them. ("Without much training" means doing something 3 to 4 times a week : ski, cycling, rollerski, running. Ranging from 1h (running) to 4h (ski, cycling)). It is acquired that an acting muscles needs to alternate beetween contracting and relaxing. There had been much research in cycling biomechanic to minimize the relaxed time. This proved to be useless because relaxing is very important to allow various reliefs, blood transfert and chemical activity before the next contraction. In that light, I wonder if "double push" is not a misleading technique where relax time is minimized and therefore performance decreased in the long run. Laurent. |
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#2
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Be relaxed
"Ken Roberts" wrote in message ...
I thought I had wrestled with every technique question, but now comes one completely different. Which muscles do you find to be the high-priority candidates for relaxing in ski skating technique? Best candidates are : neck, shoulders, hands (too firmly gripped on poles), jaw, any muscles involved in the équilibrium in general and particularly chin and buttock muscles. (Double poling in a good exersize to improve equilibrium). Example : When you try to lift something really heavy, you will inevitabily contract your jaw. Test it. Any time you struggle against something (steep hill, wind, slush, your immediate neighbour, yourself, etc..) you will contract unnecessary muscles. Well, you struggle and then your body understand that something uncommon is happening. Then it will be unconscioulsy contracted to be prepared for any event that could happen in the process. The key is that you know that nothing suprising is likely to happen because you're confident and you trust your skis. Then you can relax. But I'm not understanding the lesson about relaxation in bicycling. Laurent wrote: There had been much research in cycling biomechanic to minimize the relaxed time. This proved to be useless . . . ? Therefore winning road racers decreased their pedaling cadence turnover from 90 rpm to 70 rpm, in order to allow more "relaxing" time in each stroke cycle? or what? There has been tentatives to increase the percentage power time of quadriceps relatively to the total duration of revolution (and therefore decrease ischios). There has been several kinds of oval "plateau" (not sure of the french-to-english translation) and other "variable" gear. The lesson is that there is not only biomechanic, there is also biology. The biomechanic researchs to increase this "power" time proved to be useless, because muscles needs to rest and relax beetween each stroke. . Finding the optimal rpm is a complex caclul involving not only the duration of each stroke but also the power applied and the stress to muscles. Lance Armstrong seems to have found something in that field. More rpm means less absolute time to relax, but also less stress. The same certainly apply in XC ski. I wonder if "double push" is not a misleading technique . . . Actually "double push" in inline skate technique might result in _more_ "relaxing" time per stroke cycle for some key muscles. (Applying this "relaxing" concept can get tricky.) I've not been able to do some efficient "double push" with rollerskis, so I'm just wondering. But from the analysis at http://home1.gte.net/pjbemail/Pushpull.html#Analysis we can conclude that push time lasts 3/4 and relaxed time lasts 1/4. We can also notice from that web site that a lot of and impressive work has been done in biomechanic study, but little in biology. So, I was just wondering... Laurent. |
#3
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Be relaxed
I find that relaxation hugely relates to breathing.
When big-relaxed-breathing seems to be what is leading your style then I think you're relaxed. --Followed by effort that appears to come from your core. Perceived core effort seems to relate to relaxation to me. In bike racing this felt like my power was coming from lower back. Laurent's "without much training" of 4X/wk of 1-4hr workouts seems likely to get one in the top 20 around here. Pretty gungho, but agreed not that much in terms of national-level. -- Jeff Potter **** *Out Your Backdoor * http://www.outyourbackdoor.com publisher of outdoor/indoor do-it-yourself culture... ...offering "small world" views on bikes, bows, books, movies... ...rare books on ski, bike, boat culture, plus a Gulf Coast thriller about smalltown smuggling ... more radical novels coming up! ...original downloadable music ... and articles galore! plus national "Off the Beaten Path" travel forums! HOLY SMOKES! |
#4
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Be relaxed
Zach-
That's about the most clear, concise, and generally helpful piece of information that has been posted on this list in quite a while. Food for thought-- or meditation! chris C. SLC --- Zachary Caldwell wrote: There seems to be a very real physiological basis for the phenomenon that Laurent and Janne have identified. In the mid 90s I conducted a bunch of testing camps at the Lake Placid Olympic Training Center thanks to the support of the OTC and their physiologist, at the time, Ken Rundell. Ken had done some studies on biathletes that demonstrated a very different HR/lactate relationship when the athletes used V2 vs V1 to climb gradual hills. Lactates went much higher much faster using V2. Based on research he and others had done on speedskating positions Ken figured that this trend must have to do with the more static nature of the V2 technique. When a muscle is held in static contraction (read this as tension, the opposite of relaxation!) the intracellular pressure quickly builds to exceed the perfusion pressure of the blood supply. A tight muscle constricts blood flow which keeps oxygen from reaching the muscle (and therefor increases lactic acid production), and doesn't allow for the removal of lactate. It's interesting to note that the biggest reason that "clap" skates produced such an improvement in speed skating times has to do with the higher (more extended) leg position they allow. The old-school position was very low and consequently pretty static. With the advent of clap-skates the skaters were producing much less lactate at their old work levels. Anyway, back to relaxation and ski technique. I pointed out that not all V2 technique had to be static or tense. We had a pretty broad range of athletes moving through these camps and we noted some pretty clear stylistic differences between them. The more relaxed and fluid skiers clearly had better economy (they'd have a lower VO2 for the same workload) and lower lactate levels. A lot of this appeared to be related to balance and comfort using roller skis in a big treadmill. A guy like Kris Freeman (as a junior) was right at home and ski at really impressive workloads with apparent ease- even using a V2 technique - while a guy like Marc Gilbertson ('98 Olympian) who was older and fitter would suffer badly trying to roller ski on the treadmill. In fact, I think we decided that Marc wasn't allowed to do max tests on roller skis after a little while. So the upshot was (I think) that V2 wasn't a worse technique physiologically unless it was practiced by less proficient athletes. Maybe it's better put this way: trying to "force" yourself to match the technique of a better balanced and more relaxed skiers will not be effective. Just relax and do what you do. Then go work on balance and technique when you're not racing! Zach "Janne G" wrote in message ... Laurent Duparchy wrote: But I'm not understanding the lesson about relaxation in bicycling. Laurent wrote: There had been much research in cycling biomechanic to minimize the relaxed time. This proved to be useless . . . ? Therefore winning road racers decreased their pedaling cadence turnover from 90 rpm to 70 rpm, in order to allow more "relaxing" time in each stroke cycle? or what? There has been tentatives to increase the percentage power time of quadriceps relatively to the total duration of revolution (and therefore decrease ischios). There has been several kinds of oval "plateau" (not sure of the french-to-english translation) and other "variable" gear. The lesson is that there is not only biomechanic, there is also biology. The biomechanic researchs to increase this "power" time proved to be useless, because muscles needs to rest and relax beetween each stroke. . Finding the optimal rpm is a complex caclul involving not only the duration of each stroke but also the power applied and the stress to muscles. Lance Armstrong seems to have found something in that field. More rpm means less absolute time to relax, but also less stress. The same certainly apply in XC ski. I have found out that if i don't relax on my bike doing TT i will do a result that is about 10% worse than if i relax and do what i suppose to do. Especially i have to relax in my calf muscles or at least use them as a reference to if feel i'm relaxed enough. I have also notice that my pulse goes up when i relaxes, normally i do 30k tempo around 165Bpm but when relaxed the pulse bumps up to around 170Bpm, and the work seams to be easier at that higher pulse. The explanation i have found is that when relaxing the muscles at the right moment enable them to flush lactate out of it and by that enable them to work at a higher load at the working cycle of the crank turn. Somewhere on the intensityscale we reach the level where the lactate can't be emptied from the muscle at the rate it's is produced, this is the level where we just can go short high power burst, so pushing the lactate cleansing ability up enables us to produce more power ower longer time (at least until your body can't cope with the increased amount of lacate produced). But from the analysis at http://home1.gte.net/pjbemail/Pushpull.html#Analysis we can conclude that push time lasts 3/4 and relaxed time lasts 1/4. We can also notice from that web site that a lot of and impressive work has been done in biomechanic study, but little in biology. So, I was just wondering... Do you whan't more analysis?: http://home1.gte.net/pjbemail/Index.htm -- Forward in all directions Janne G __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com |
#5
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Be relaxed
Jeff Potter wrote in message ...
One indicator for me of when I'm skiing relaxed is that I can easily change technique sometimes with every stroke if the terrain wants that, so that I'm letting my core and the terrain dictate how I ski and am not limited by tension or awkwardness in various positions. ---It would probably be a hard kind of skiing to follow exactly! Also, I recall when a train of racers is going real nice in mixed terrain they're following each others' core, not their specific moves---(...) OTOH at least the lesser talents among us probably all have experienced the opposite: trying to keep up with someone by trying to mimic his "stride" frequency or length - with the inevitable result of becoming more inefficient, out of sync with the contours of the trail and, if wisdom doesn´t begin to prevail pretty darn quick, extremely unrelaxed and, then, in a lactate spiral of death... For me, this can be noticeable within two loops of 1.5km: I can try and skate behind a 15-year-old smooth mover in n:nn/loop and on the second one I will be grateful when the downhill section begins - yet when I skate in my own inimitable style and rhythm I´ll feel relaxed in not a second over n:nn! (Of course, I *would* be a *better* skier, if I had the kid´s natural(?) technical ability, but trying to force or "will" myself into it is never a good idea...) Anders |
#6
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Be relaxed
This "static" contraction or tension might be a different kind of fatigue
than from using the same muscles to directly power motion. I say that because of my experience last weekend: On Saturday I did 47 km of moderately hard skating on inlines (with no poles) in a race. Afterward my leg muscles were so sore and tired I could barely walk. So I was thinking I would be forced to cancel my bicycle ride with Sharon planned for Sunday. But I got on the bicycle and it was no problem. I easily rode about 130 km / 80 miles that next day, and we took on several extra hill climbs. No pain after 15 minutes warmup. An obvious interpretation is that inline skating tends to put me in a lower body position (for better aerodynamics and more range-of-motion in pushing). Without poles, my quadriceps muscles must support the weight of my upper body. But when bicycling, my upper body rests on the saddle most of time. Even though pedaling uses my quads a lot, it does not use them in that "static" way -- so no pain. Ken ______________________________________ Zachary Caldwell wrote . . . Based on research he and others had done on speedskating positions, he figured that this trend must have to do with the more static nature of the V2 technique. When a muscle is held in static contraction (read this as tension, the opposite of relaxation!) the intracellular pressure quickly builds to exceed the perfusion pressure of the blood supply. |
#7
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Be relaxed
But if V2 (versus V1) used energy at a 10% greater rate per unit time
(that's the meaning of power, I believe), but resulted in 15% greater speed, it would be more efficient, not less. Presumably that's preferable if you can avoid putting your heart rate up into a range which uses too much glycogen or produces too much lactic acid. I'm not claiming that this is a good idea, just pointing out that raising the HR isn't the only variable. Presumably those treadmill tests were at a constant speed. Best, Peter |
#8
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Be relaxed
Yes I was assuming that the tests were at constant speed, since otherwise
the efficiency question would be completely different, as Peter pointed out. "Efficiency" is another whole tricky thing. The obvious kind we might call efficiency of motion technique -- or let's talk in terms of inefficiency: (a) work used in recovering body position for the _next_ forward push, versus work used directly to power forward motion. (b) work used in accelerating the skier's center of mass side-to-side or up-and-down, versus pushing the skier forward. All skating and classic techniques have significant inefficiency of motion technique -- but some techniques have more than others (especially when badly executed). Which technique is the _most_ efficient? Answer is the same for all skiing situations: Lie down on the snow. There are more kinds of efficiency which are important -- muscular or physiological efficiencies. There are several resources (and several "capacity dimensions" of those resources) that skier's body uses in skating performance -- and which could _limit_ speed in some situations, or at least impact it: (c) Oxygen transport capacity / VO2max (d) Glycogen "fuel" available to the muscles. (e) Lactate clearance capacity in specific peripheral muscle groups. Peter wrote if you can avoid putting your heart rate up into a range which uses too much glycogen or produces too much lactic acid. I think there are other dimensions of performance capacity than just lactate and VO2max: (f) single-repetition or low-number-of-repetitions "peak force" capacity of specific muscles (or joints) in a specified range of motion. This is readily observable using weight machines: max weight for 1 rep versus 5 reps versus 12 reps versus 30 reps. Max weight for 40-degree knee bend range of motion versus 80-degree knee bend. But it's mostly _not_ a "lactate" limit. Clearly a different additional dimension of muscle performance -- related to "gearing" leverage -- seems especially relevant up steep hills. (g) static isometric capability of specific muscles: Dependent on joint configuration, time, force-weight. Seems like there's some lactate impact here, but I doubt that it's all just a lactate limit thing. Managing this limit is a big factor in ice speedskating technique and training. (h) "repetitive motion stress" handling capacity of specific joints and ligaments. This one can be the limit that makes a weekend warrior fail to finish a marathon. Runners hit this limit in their knees and ankles. Sometimes with XC skiers it's in the spine. Different limits become "actively critical" for different techniques in different races and different terrain/competitive situations during a single race. The only kinds of efficiency that _matter_ are the efficient use of capacity limits that are actively critical in _this_ particular situation. So which limits are relevant or critical for skating up a hill? I'm understanding the study that Zachary Caldwell reported to be proposing that (g) is a key factor for skating up hills with V2 (compared with V1). I'm not hearing (yet) a claim that V2 is better than V1 on flat terrain. My response is Yes, (g) is a relevant factor impacting V2 performance up a hill. But I'm suggesting that that there are other dimensions that are more critical for skating up a hill: like motion inefficiency (b) and peak-force capacity (f) -- and those two factors are stronger differentiators between V2 and V1. Ken __________________________________________________ _ Peter wrote But if V2 (versus V1) used energy at a 10% greater rate per unit time (that's the meaning of power, I believe), but resulted in 15% greater speed, it would be more efficient, not less. Presumably that's preferable if you can avoid putting your heart rate up into a range which uses too much glycogen or produces too much lactic acid. I'm not claiming that this is a good idea, just pointing out that raising the HR isn't the only variable. Presumably those treadmill tests were at a constant speed. |
#9
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Be relaxed
Jeff Potter wrote
What about the idea that a straighter, more upright, more bone-on-bone posture is MORE relaxing? Yes, and there's something else that's even more relaxing: Lying down on the snow. Which goes to show that not all forms of relaxing are equally valuable in attaining that critical goal of not finishing too far behind your buddies in the big race. A couple of relevant facts: -- from biomechanics: You can't use your big quad and glute muscles unless you first _flex_ your knees and hips. -- from geometry: The closer your hip joint is to the ground, the longer the range-of-motion you can push your leg through without losing contact with the snow (and the more your leg-push is directed in the horizontal plane of motion rather than vertically downward). Then I see the mention of the clapskate being prefered due to the straighter glide leg it allows. The old non-clap design already "allows" any speedskater to glide on as straight a leg as they choose. What the Pilot-like free-heel clap-skate permits is a longer effective range of leg-push motion -- by using the calf muscles to extend the toe at the very end of the push. What to _do_ with that longer range of motion is a choice by the skater. Speedskaters could keep their hip nearly as low as before, but push thru a longer distance in contact with the ice surface. Or they could raise their hip some, and push thru the same distance in contact with the ice. Since static isometric tension is such a critical limiting factor in ice speedskating performance, they choose the second. It doesn't prove anything about toe-push not being valuable. And it doesn't prove anything about optimal V2 technique (which is done with poles, on snow). Ken |
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