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[技术] 编译:职业公路自行车运动员踏频与效率的关系

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  • TA的每日心情

    2015-12-31 00:06
  • 签到天数: 200 天

    [LV.7]常住居民III

    发表于 2014-4-22 13:28 | 显示全部楼层 |阅读模式
    本帖最后由 yangt1193 于 2014-4-23 08:35 编辑

    忙着搬砖,一直在想自行车运动员的体成分问题,刚好看到踏频的文章,所以粘过来,弄错了。谢谢医生大人提醒  

    期刊:Med Sci Sports Exerc. 2004 Jun;36(6):1048-54. 【运动医学与科学,2013年影响因子
    4.475 】
    题目:In professional road cyclists, low pedaling cadences are less efficient
    作者:Lucia A1, San Juan AF, Montilla M, CaNete S, Santalla A, Earnest C, Pérez M.
    作者单位:  Exercise Physiology Laboratory, European University of Madrid, Madrid, Spain. alejandro.lucia@mrfs.cisa.uem.es

    摘要:
    PURPOSE:
    To determine the effects of changes in pedaling frequency on the gross efficiency (GE) and other physiological variables (oxygen uptake (VO2), HR, lactate, pH, ventilation, motor unit recruitment estimated by EMG) of professional cyclists while generating high power outputs (PO).
    METHODS:
    Following a counterbalanced, cross-over design, eight professional cyclists (age (mean +/- SD): 26 +/- 2 yr, VO2max: 74.0 +/- 5.7 mL x kg x min) performed three 6-min bouts at a fixed PO (mean of 366 +/- 37 W) and at a cadence of 60, 80, and 100 rpm.
    RESULTS:
    Values of GE averaged 22.4 +/- 1.7, 23.6 +/- 1.8 and 24.2 +/- 2.0% at 60, 80, and 100 rpm, respectively. Mean GE at 100 rpm was significantly higher than at 60 rpm (P < 0.05). Similarly, mean values of VO2, HR, rates of perceived exertion (RPE), lactate and normalized root-mean square EMG (rms-EMG) in both vastus lateralis and gluteus maximum muscles decreased at increasing cadences.
    CONCLUSIONS:
    In professional road cyclists riding at high PO, GE/economy improves at increasing pedaling cadences.

    目的:研究专业自行车运动员在大功率运动时踏频的变化对总效率(gross efficency,不知这个术语在单车训练中指的什么指标,用什么仪器测量)和生理指标(摄氧量、心率、乳酸水平、血液pH值,通气阈以及用肌电图评价的运动单位募集—就是肌纤维募集动员程度)的影响。

    方法:采用平衡交叉设计对8名专业自行车运动员(平均年龄26±2岁,最大摄氧量74.0±5.7 ml/kg/min)分别以60、80和100 转/分钟 的踏频进行三次运动运动测试,每次运动强度固定(功率输出为366±37瓦),每次测试时长为6分钟。

    结果:60、80和100 转/分踏频对应的总效率分为别22.4±1.7,23.6±1.8和24.2±2.0。100 转/分钟踏频时的功率显著高于60 转/分钟的总效率(P < 0.05)。而摄氧量、HR和体力感觉等级量表(PRE量表)值、乳酸和股外侧肌及臀大肌的归一化均方根肌电图结果也呈同样的趋势。

    结论:专业公路自行车运动在大功率输出是,总效率和机能节省化随着踏频的提高而出现优化。

    ----
    术语:
    最大摄氧量(maximal oxygen consumption, VO2max)是指在人体进行最大强度的运动,当机体出现无力继续支撑接下来的运动时,所能摄入的氧气含量。作为耐力运动员的重要选材依据之一,是反映人体有氧运动能力的重要指标,高水平最大摄氧量是高水平有氧运动能力的基础。
    乳酸阈:人体在渐增负荷运动中,血乳酸浓度随运动负荷的渐增而增加,当运动强度达到某一负荷时,血乳酸浓度急剧上升的开始起点,称为乳酸阈。
    最大吸氧量受遗传因素的影响,而训练可以提高乳酸阈。Davis的研究指出,经过系统训练后的受试者,最大吸氧量只能提高25%,而乳酸阈却提高44%。其原因是遗传因素限制了最大吸氧量的提高幅度,而乳酸阈值主要与外周的代谢因素的关系更密切,例如:肌肉的血流量、肌纤维类型的百分组成及酶的活性等。训练可以改善代谢能力,使乳酸阈值较大幅度的提高。
    ③ 肌电图:
    肌电图(electromyography,EMG),应用电子学仪器记录肌肉静止或收缩时的电活动,及应用电刺激检查神经、肌肉兴奋及传导功能的方法。通过此检查可以确定外周神经、神经元、神经肌肉接头及肌肉本身的功能状态。

    ----
    从此项研究结果可看出,在固定功率输出前提下,运动员在高踏频(100)时的心率、乳酸堆积程度和肌纤维激活及募集程度方面相较于低踏频(60)而言,有一定的优势。

    不知道大家在爬龙井(距离固定:2.65 km,功率输出相对固定:每个人的最大能力相对稳定、所能蹬动的齿比也相对稳定的前提下)时,踏频是多少?最大心率是多少?
    当然业余运动员没有专业运动员那么强的肌肉工作能力和心肺耐力,但是每个人自身潜力是否挖掘足够呢?

    另,此项研究也有些问题不能很好的回答:80和100的踏频孰优孰劣?90呢?当然,在固定大功率输出的前提下,不可能无限制提高踏频。首先还是认真提高肌肉力量、心肺耐力,到了一定程度出现上升瓶颈时可能才会更关注这些东西吧。

    我个人初步关注的重点是其测试方案和研究方法,具体的分析和讨论还没仔细消化,有兴趣者可以去仔细研究研究!对训练或许会有点帮助和启发







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  • TA的每日心情
    慵懒
    2018-12-5 21:19
  • 签到天数: 22 天

    [LV.4]偶尔看看III

    发表于 2014-4-22 16:20 | 显示全部楼层
    你这个内容和题目???
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  • TA的每日心情

    2015-12-31 00:06
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    [LV.7]常住居民III

     楼主| 发表于 2014-4-22 20:40 | 显示全部楼层
    本帖最后由 yangt1193 于 2014-4-22 20:48 编辑

    以前看过的有印象的帖子,大致印证下上面的内容。

    这只禽兽提到了爬龙井时的踏频:十上十下,踏频 90~97,腿软……成绩从10'33'' ~ 6'56''   
    http://hzbike.com/forum.php?mod= ... p;extra=&page=2

    还有一只禽兽说他爬龙井,最大心率在194 bpm,帖子找不到了,给不出链接了







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  • TA的每日心情

    2015-12-31 00:06
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    [LV.7]常住居民III

     楼主| 发表于 2014-4-22 21:38 | 显示全部楼层
    Int J Sports Med. 2008 Mar;29(3):244-50.

    Cadence-power-relationship during decisive mountain ascents at the Tour de France.

    Vogt S1, Roecker K, Schumacher YO, Pottgiesser T, Dickhuth HH, Schmid A, Heinrich L.

    Author information
    Department of Preventive and Rehabilitative Sports Medicine, University of Freiburg, Freiburg, Germany. stefan.vogt@uniklinik-freiburg.de

    Abstract

    The aim of the study was to report the relationship between cadence and power developed by professional cyclists during high mountain ascents of the Tour de France. From the 10 cyclists (30 +/- 4 years, 178 +/- 8 cm, 69 +/- 6 kg) involved in the study, 108 ascents were recorded and analyzed using a mobile power measurement device (SRM Training Systems, Jülich, Germany). Based on topographic characteristics, the ascents were categorized into 1st and Hors Category (HC) climbs. During the ascents of the 1st Category climbs, power output averaged 312 +/- 43 W (4.5 +/- 0.6 W/kg) with a mean cadence of 73 +/- 6 rpm and a mean duration of 37 : 41 +/- 16 : 16 min. Power output averaged 294 +/- 36 W (4.3 +/- 0.6 W/kg) at a mean cadence of 70 +/- 6 rpm during 57 : 40 +/- 10 : 32 min on HC climbs. The maximal mean power for long durations (1800 s) showed a mean power output of 327 W and 346 W for the 1st and HC climbs, respectively. The evaluation of the cadence-power output and the distance per pedaling cycle-power output relationship shows that high power outputs are mainly yielded by higher pedaling cadences and higher gears.

    我有个疑问,为什么看到国外各车队科研人员或者研究所发表的东西,其运动员功率输出都在 ~400 W,而论坛里的各种禽兽,一说蹬车就上个5、6、7、800 W呢?请明白的前辈指教。

    这项研究被试(运动员)基本情况如下:
    居然每年30, 000 ~ 35, 000 km的训练量,么么滴个神啊!




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  • TA的每日心情
    慵懒
    2018-12-5 21:19
  • 签到天数: 22 天

    [LV.4]偶尔看看III

    发表于 2014-4-22 22:32 | 显示全部楼层
    yangt1193 发表于 2014-4-22 21:38
    Int J Sports Med. 2008 Mar;29(3):244-50.

    Cadence-power-relationship during decisive mountain asc ...

    设备不同啊。骑行台上测出来的数据当然不准确了。
    下次我们集体去你那里做测试好不好。
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  • TA的每日心情
    开心
    2014-8-14 00:52
  • 签到天数: 1 天

    [LV.1]初来乍到

    发表于 2014-4-22 23:00 | 显示全部楼层
    新人菜腿,平时夜骑踏频一般在70-80之间,平路速度也只有在25km/h左右,听说最佳踏频是90-110。今晚尝试把踏频提高到80-90,同样的线路(梅家坞一圈),无论心率或速度,以及个人感觉,好像都没有什么明显变化。不过这只是极低水准和短距离测试,不具参考意义吧。






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  • TA的每日心情

    2015-12-31 00:06
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    [LV.7]常住居民III

     楼主| 发表于 2014-4-23 06:46 | 显示全部楼层
    本帖最后由 yangt1193 于 2014-4-23 08:53 编辑
    医生 发表于 2014-4-22 22:32
    设备不同啊。骑行台上测出来的数据当然不准确了。
    下次我们集体去你那里做测试好不好。


    好啊,我这里除了EMG,上文中涉及到的最大摄氧量等指标都能测,包括三大物质的能量代谢(从固定强度、功率输出时的耗氧量和CO2呼出量进行推算,indirect method中最准确的方法)……意大利的Cosmed全套,精度顶级。
    可我这里没有功率自行车(Monark可以到1000W+),不行您就自带一个禽兽们踩不爆的骑行台
    普通禽兽的数据也很好用的,只要能把方案设计好。这个可以讨论,专项特点方面您们都是专家!

    后来看那文章还是有些交待的……昨天上不去论坛了,后来就没法贴图了,补上。



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  • TA的每日心情

    2015-12-31 00:06
  • 签到天数: 200 天

    [LV.7]常住居民III

     楼主| 发表于 2014-4-23 08:59 | 显示全部楼层
    本帖最后由 yangt1193 于 2014-4-23 13:08 编辑

    额,这项研究好像国外很多车队和同行都挺重视。西班牙 Lucia 女士他们这个团队,以前的帖子中有提及过。

    Preferred pedalling cadence in professional cycling

    LUC&Iacute;A, ALEJANDRO; HOYOS, JES&Uacute;S; CHICHARRO, JOS&Eacute; L.


    Abstract

    LUC&Iacute;A, A., J. HOYOS, and J. L. CHICHARRO. Preferred pedalling cadence in professional cycling. Med. Sci. Sports Exerc., Vol. 33, No. 8, 2001, pp. 1361–1366.
    Purpose: The aim of this investigation was to evaluate the preferred cycling cadence of professional riders during competition.
    Methods: We measured the cadence of seven professional cyclists (28 ± 1 yr) during 3-wk road races (Giro d’Italia, Tour de France, and Vuelta a Espa&ntilde;a) involving three main competition requirements: uphill cycling (high mountain passes of ∼15 km, or HM); individual time trials of ∼50 km on level ground (TT); and flat, long (∼190 km) group stages (F). Heart rate (HR) data were also recorded as an indicator of exercise intensity during HM, TT, and F.
    Results: Mean cadence was significantly lower (P < 0.01) during HM (71.0 ± 1.4 rpm) than either F and TT (89.3 ± 1.0 and 92.4 ± 1.3 rpm, respectively). HR was similar during HM and TT (157 ± 4 and 158 ± 3 bpm) and in both cases higher (P < 0.01) than during F (124 ± 2 bpm).
    Conclusion: During both F and TT, professional riders spontaneously adopt higher cadences (around 90 rpm) than those previously reported in the majority of laboratory studies as being the most economical. In contrast, during HM they seem to adopt a more economical pedalling rate (∼70 rpm), possibly as a result of the specific demands of this competition phase.







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  • TA的每日心情

    2015-12-31 00:06
  • 签到天数: 200 天

    [LV.7]常住居民III

     楼主| 发表于 2014-4-23 09:10 | 显示全部楼层
    本帖最后由 yangt1193 于 2014-4-23 13:12 编辑

    High Cadence vs Low Cadence Cycling

    A smooth, fluid pedal stroke combined with a good cadence is an integral part of riding fast and efficiently (and therefore winning races.)  Cadence can be described simply as your pedaling speed. It is measured in Revolutions Per Minute, or RPM. This is the number of times your legs complete full circles in 60 seconds of riding.

    Cadence varies between riders and even the same rider will vary their cadence in a given situation, but most elite riders use a fast cadence. There is no “one size fits all” perfect cadence, but we’ll look at the differences between the high and low cadences in this article.

    For the purposes of this article, I will use the following measurements to describe cadence:



    Very slow: 50-70  RPM

    Slow: 70-80  RPM

    Moderate: 80-90  RPM

    Fast: 90-100  RPM

    Very Fast: 100-110  RPM

    Extremely Fast: 110+  RPM



    To simplify even further, you can consider anything under 90 RPM to be a low cadence, and 90+ RPM would be a high cadence.

    High vs Low Cadence: The Pros and Cons
    Let’s start by looking at the pros and cons of each cadence…

    If you are riding with a high cadence in an easy gear, pedaling is going to tax your cardiovascular and respiratory systems. If you have a strong heart and lungs, you can probably hold a fast cadence for a long period of time. Because of the easy gear, it will produce less strain on your muscles.
    Low cadence riding in a hard gear taxes your skeletal muscles, specifically your quads. Since you’re using a big gear, you have to apply lots of force to turn it. If your legs are very big and powerful, this may work well for you.
    Turning the big gear slowly has less effect on your heart and lungs, so you’re less likely to be gasping for air or have a skyrocketing heart rate.
    However, there is an edge towards the higher cadence riding. Your heart and lungs can take repeated punishment for long periods of time (and they recovery quickly after hard efforts,) while your muscles will fatigue relatively quickly.
    A high cadence also places less stress and torque on your knees. So if you have bad knees, you’re usually better off spinning faster, in a low gear.
    There is also a tactical advantage to using a high cadence. Spinning fast in a low gear allows for faster accelerations, because you can bump up your cadence even more to increase your speed. If you need to shift gears, that’s also easier, since the drivetrain in under less stress.
    If you’re pushing a big gear and the pace changes, you’re in trouble. You won’t be able to change cadence or shift gears quickly, so you may get dropped.


    Cadence in the Pro Peloton
    The most noteworthy example of cadence in the pro peloton is the rivalry between Jan Ullrich and Lance Armstrong in the mountain stages of the Tour de France. When Lance came back to win the Tour, he was riding at a very fast cadence, usually 110rpm or more. Ullrich, on the other hand, was grinding out the big gears at a cadence closer to 65-70rpm.

    While both riders were very talented, Lance and his higher cadence always seemed to get the better of Ullrich (and everyone else in the race, for that matter.) But don’t forget, Jan Ullrich won the Tour back in 1997, so it’s entirely possible that some future TdF champs will be turning the pedals slowly.【这样的讨论是不是太有意思了?】
    I’d put my money on a higher-cadence rider, though. There has been at least one study of professional cyclists (from the European Journal of Applied Physiology,额,欧洲应用生理学杂志,我们实验室有篇本科生论文:用超声研究普通人低氧运动时心脏左室功能变化的论文发表在此刊物,2007年) that showed a link between high cadence riding and better overall performance. The reasoning is that the less tension on the muscles, the longer you have before fatigue sets in.【仅一项研究就值得这教练员这么下赌注?

    Since I don’t have cadence data for all pro riders, I can’t specify what cadence is the most popular, but I’d venture a guess that most riders fall in the 80-100rpm range, depending on the situation. Especially today, with studies and anecdotal evidence supporting a high cadence for performance riding.

    Finding Your Most Efficient Cadence
    Despite the edge in favor of high cadences, the best thing to do is perform some tests to determine your optimal cadence.

    Time Trial Cadence Test  ★
    这些东西跟上面研究中采用的protocol很有相似的地方,只是研究更为严谨而已?

    The easiest way to determine your optimal cadence is by performing a time trial multiple times, using a different cadence each time.

    First, determine a course on local roads that takes about 10 minutes to complete. This route will be the same for each time trial.

    Next, perform a time trial on the course at a cadence of 80rpm. When finished, record your time and rating of perceived exertion (RPE.)

    Ride easy for 15-20 minutes, then perform another time trial, this time using a cadence around 95-100rpm. When finished, record your time and RPE.
    A couple days later, perform the same test again, but do the first time trial at a high cadence and the second time trial at a low cadence.

    Now you can compare the data. Whichever cadence produced faster times and lower RPE values is probably your ideal cadence.
    For example, if the slow cadence has your legs burning and your average speed slowing down, while you feel great at a high cadence and cut a minute off your slow cadence trials, it’s a safe bet that you should be riding at a high cadence.

    You could perform this test multiple times for a better sample size, but in general, you’re just comparing how fast you could ride a course at different cadences. If you want to get specific, you could try doing time trials at 80rpm, 85rpm, 90rpm, 95rpm, 100rpm, 110rpm, etc.

    If you ride comfortably somewhere in the range of 85-110rpm, that’s probably good.


    Hill Climb Cadence Test  ★
    Find a hill climb that takes about 3 minutes to complete. (You’ll be doing more time trials, but you won’t need to record data.)

    On trial one, ride the first 2/3 of the hill in a low gear and a cadence around 95rpm. For the last 1/3, use whatever gear and cadence you want.
    On trial two, ride the first 2/3 of the hill in a big gear and a cadence around 80rpm. For the last 1/3, use whatever gear and cadence you want.
    To get the results, just remember what you did on the last 1/3 of the hill in each test.

    For the last 1/3 of the hill, you probably wanted to recover, and you would have switched to whatever cadence is more comfortable for you. If you were staying in and switching to a lower gear and high cadence, then high cadence riding is for you. If you couldn’t wait to shift to a harder gear and slow your cadence down so you could catch your breath, then you may be best suited for big gear and low cadence riding.

    Cadence Summary
    There are pros and cons to high and low cadences. You should test out a variety of cadences and ride what is most comfortable and fastest for you.
    The ‘right’ cadence is different for everyone, and you’ll probably vary your cadence depending on the terrain, so you don’t have to freak out about getting the exact cadence. All I can say is that your ideal cadence will fall somewhere between “holy sh*t my legs are on fire!” and “I… can’t… breathe!”
    If you can’t seem to pick a favorite RPM within that range, err on the high cadence side, just below the point where you can’t breathe steadily.

    或许,这些东西再往前一小步,比fitting会有意思得多?




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  • TA的每日心情
    无聊
    2016-3-16 14:12
  • 签到天数: 667 天

    [LV.9]以坛为家II

    发表于 2014-4-23 12:30 | 显示全部楼层
    踏频去年就拆了,那时候还骑山地..龙井一般75-80,那会没用心率带,踏频玩过就腻了


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  • TA的每日心情

    2015-12-31 00:06
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    [LV.7]常住居民III

     楼主| 发表于 2014-4-23 13:14 | 显示全部楼层
    野人LW 发表于 2014-4-23 12:30
    踏频去年就拆了,那时候还骑山地..龙井一般75-80,那会没用心率带,踏频玩过就腻了

    你是一只野壕,让我们这种连码表都不装的人情何以堪?
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  • TA的每日心情
    擦汗
    2014-8-27 06:53
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    [LV.9]以坛为家II

    发表于 2014-4-23 13:14 | 显示全部楼层
    现在科学的骑车还是不多啊
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