2009. augusztus 26., szerda

Napi olvasmány: a szívizom adaptációja az edzéshez

Az alábbi olvasmányból megtudhatjuk, hogy a sportoló és az átlagember szive között a legnagyobb különbség a stroke volumen. A nagyobb stroke-volumen (vér kipumpálása a balkamrából szivverésenként) eredményezi az alacsony nyugalmi pulzust. A nagyobb stroke-volumen szorozva sok összehúzódással pedig nagyobb szívteljesítményhez vezet, ezáltal növekszik a vo2max.

Myocardial Adaptations to Training

© 1996 Stephen Seiler

The heart, in cellular composition, structure, and mechanics, is an absolute marvel of "biological engineering". Even among human couch potatoes, it is an astoundingly well-equipped endurance muscle. It has an incredibly dense network of capillaries (over 2000 capillaries per cubic millimeter!) designed to provide reliable delivery of oxygen to the working muscle with a minimum diffusion distance to intracellular mitochondria. The individual heart cells (called myocytes) are densely packed with mitochondria; they take up about 20-25% of the human heart cell volume. In contrast, mitochondria make up less than 5% of the untrained skeletal muscle cell volume. The specific biochemistry of the muscle cells is designed to minimize lactate production even at very high workloads (H isoform of lactate dehydrogenase for you scientists). The heart can metabolise fat, lactate, and blood glucose with equal effectiveness.

So, how can endurance training improve a muscle that is already superbly designed and equipped to perform constant work? The answer is fairly simple. IT GETS BIGGER! (OK, it's slightly more complicated than that). Endurance trained hearts do not beat faster at maximum. They do not beat more powerfully, gram for gram. They also do not change significantly in terms of mitochondrial or capillary density. The distinction between the athlete's heart and the sendentary heart is the larger stroke volume of the trained heart. This improvement is critical to improved endurance performance. Why? The heart is first and foremost a pump. It pumps oxygenated blood to the body to support the production of cellular energy. During exercise, working muscles increase their cellular energy requirements up to 100X. Generating more energy (ATP) requires more oxygen delivery to the mitochondria.

The quantity of work that can be performed by the muscles over an extended period of time is critically dependent on the volume of blood that can be delivered by the heart. A body supplied more oxygen by a bigger pump has the potential to sustain work at a greater maximal intensity. Maximal Cardiac Output = Maximal Heart Rate X Stroke Volume. Stroke volume is the volume of blood ejected from the left ventricle each beat. Endurance training impacts myocardial function 1) at rest, 2) during sub-maximal exercise, and 3) during maximal exercise.

Resting Hemodynamics and Exercise

At rest the stroke volume and resting heart rate of the average person can be remembered easily as approximately 70 ml/beat and 70 beats/minute. This gives us 70X70 or roughly 5 liters/minute resting cardiac output (5,000ml/min). The resting cardiac output is determined by the oxygen demand at rest, and also by the need for high blood flow to the kidneys for filtration purposes. It doesn't change appreciably with endurance training. However, the manner in which the heart delivers this resting demand does change. After 6 months of endurance training, the resting heart rate may decrease to 55 bpm. At the same time, resting stroke volume increases to about 90 ml (HR x SV stays the ~same before and after training). So a reduced resting heart rate is a hallmark of endurance training. Resting heart rate (RHR) can be much lower. In champion endurance athletes, RHR is often in the 30s and low 40s. Since resting oxygen demand still hasn't changed, this should tip you off that these athletes have extremely high resting stroke volumes! Thus, the resting heart of the athlete is more efficient. It performs the same work with fewer beats and less myocardial energy demand. However, since some medical symptoms are also marked by a reduced resting heart rate, your physician may initially raise his/her eyebrow to your low frequency lub-dub during checkups.

Having said all that, I feel I need to muddy the water a bit. First, while a lower resting heart rate is a typical feature of the endurance-trained heart; there is substantial variability in the resting heart rate and its response to training. Recent studies (i.e. the Heritage Study for those interested) have demonstrated a substantial genetic variability in the responsiveness to training. So, some people will respond more dramatically to the same training stimulus than others. Second, another typical feature of the highly endurance trained heart is arrhythmias. It is not unusual for well-rained athletes to show some conduction abnormalities. Often, these are present at rest, but disappear as soon as exercise starts. So, while a low heart rate in and of itself is no reason to worry, doctors do understandably take notice if that steady lub-dub sound shows repeated hiccups. Some heart hiccups are more serious than others, so humor them.

Myocardial Responses to Sub-maximal Exercise Before and After Training

When we begin to exercise at any given intensity, more oxygen must be delivered to the working muscle. Cardiac output increases in proportion to the increased energy demand. If we measure the responses of an individual to running at 8 min mile pace before and after 3 months of regular exercise, here is what we will see. First, the metabolic cost of working at this intensity will be unchanged (assuming no major improvement in running efficiency). Therefore cardiac output will be the same. However, just as during rest, the heart will deliver more blood each beat. Therefore heart rate at this and any sub-maximal exercise intensity will be reduced. Using the analogy of a car engine, we have replaced a small motor with a larger one that achieves the same horsepower at lower rpms. Of course, this change is a major reason why Polar Electro in Finland sells so many fancy “computer downloadable” heart watches around the world. The reduction in heart rate at sub-maximal workloads is a quantifiable, easy to measure indicator that we are adapting to training, and they have convinced us that we need to keep track of that!

Hemodynamic Response to Maximal Exercise

There is for all of us an exercise intensity that will elicit our maximum cardiac output. Once this limit is achieved, further increases in work intensity will result in no further increase in heart rate. By definition, this is then the maximum heart rate. The maximum heart rate in humans varies from individual to individual and decreases with age. Therefore the only way to know precisely what a specific person's maximal heart rate is would be to do a maximal exercise test. Without such precise knowledge, we often use the formula "220 minus age" to approximate maximal heart rate. This formula will generally give results within plus or minus 10 bpm of reality. True maximal heart rate may not be achieved in some forms of exercise that do not employ a large enough muscle mass, or if the person is unfamiliar with the mode of exercise employed. For example, one person may have a true maximum heart rate of 195 achieved during uphill running, but only 191 during a cycling test, and 187 during swimming. These latter heart rates are termed peak heart rates and should be used as a basis for determining training intensity for a specific exercise mode.

The important thing to remember is: Maximal heart rate does not increase after training. It stays the same (or might even decrease just slightly). However, maximal stroke volume increases. Therefore maximal cardiac output increases in response to exercise. This is the primary reason for the increase in VO2 max!

So, in response to endurance exercise the heart adapts by increasing stroke volume at rest, during sub-maximal exercise, and during maximal exercise. There is some debate regarding whether stroke volume increases BECAUSE heart rate is decreased (increasing diastolic filling time), or because of an increase in ventricular volume due to eccentric hypertrophy of the heart muscle. Both factors probably contribute based on the available data. Both changes also rapidly revert towards normal with the cessation of training. One other important change that takes place is an increased blood volume. Increased blood volume helps to take advantage of the increased filling capacity of the heart and facilitates increased stroke volume. This adaptation occurs fairly rapidly with training, but is also the first adaption lost if we stop training for several days!


2009. augusztus 23., vasárnap

Muzak: James Lavelle - GU 037 Bangkok

Augusztus 3-án jött ki az új GU mix album, ami azért érdekes, mert James Lavelle csinálta, aki az UNKLE tagja. Meghallgatjuk oszt meglássuk, milyen. Nem fejlődnek az utóbbi években a progressive, deep és hasonló stílusok..

part1
part2

Ja és majd töröld le, ha meghallgattad..

UPDATE: meghallgattam, többször is. Szomorúan konstatálom, hogy az UNKLE végleg elment ebbe a rettentő fejfájós masszás britpop hangzásba, így az albumra bepasszírozott UNKLE számok nem tetszettek. Az első albumon az 5-6-7 számok körül van némi hallgatható, bár ezek olyan régiek, mint amikor kb. abbahagytam a prog zenék hallgatását, Nathan Fake - You Are Here , James Holden - 10101 Radiohead - Reckoner (James Holden Remix) , ezután megint beindul a rettentő fejfájós rész, buzeránsénekléssel (Layo & Bushwacka! - Life2Live (UNKLE Surrender Sounds Session #1) az ezt követő részben van néhány finomabb track, egészen az utolsó előtti számig, amikor megint rettentő vonítást hallhatunk.
A második CD sokkal inkább ínyemre való: egy nem-annyira-kellemetlen-denemistúljó UNKLE intro és blokk után egész jó kittyegős minimal-deep dalok következnek, először a System 7 Spacebird (Dubfire Deep Space Remix) aztán feltehetően a csíra-bulik nagy kedvence, (mivel hallottam már rádió spotban szerepelni), mindenképpen kiemelkedő mű következik - főleg a mai igen fos progressive/deep felhozatalban - a Radio Slave - Grindhouse (Dubfire Terror Planet Remix). Ezt eltalálták, már a mini-mixen felfigyeltem erre a számra, sőt, ez volt az egyetlen, ami a minimixben jó zene volt. Innentől jó zenék következnek, Mark Broom - Tewnty Nine 2009-es remixe majd Fergie - Break In, na ez igazán atom, teperős-zakatolós, helyenként felsíró spacey sweep-pel (középtájon a kiállásnál hallható akkordozás hasonlít a 1,5 éve készülő de hamarosan talán befejeződő Kraftwerk - Robots remixem akkord stack-jára :-)) A következő szám egy régi kedves ismerős, pont egy másik Lavelle mixben hallottam, az Atmospherics-ben: Chelonis R. Jones - Deer In The Headlights (Radio Slave Remix) - ezek a Radio Slave-ék nagyon érzik a hangzást. Erre a trackre nagyon ügyesen lett rámixelve Gavin Herlihy - Machine Ate My Homework-ja, ami egy finom arpeggiot tartalmazó "küzdelmi" zene, ezután pedig Holden kietlen, magárahagyatott hangzásának egyik jobb darabja, a The Wizard következik, a maga kis mesebéli dallamocskájával. Kár volt az utolsó szám elé beerőltetni mégegy fejfájdítást, mert a Mystery Jets - Two Doors Down Duke Remont feldolgozásában igazi gyöngyszem, valódi albumzáró. Szerencsére az eredeti számhoz, amit most hallgattam meg a Youtubeon, nincs semmi köze, viszont olyanra sikerült, mint egy régi UNKLE zene..kellemes szomorkás melódia, gitárriff, kórus, a szétszórt elhaló chip-bleepekből kialakuló szép arpeggio pedig kiba**tt zseniális! ...nagy, nagy kár, hogy BÁCSIÉK inkább rockzenészek akartak lenni..
Íme az album legértékesebb zenéje:


2009. augusztus 21., péntek

Edzési zónák (intenzitás) kerékpárosoknak

A mai napig sokak számára nem tiszta, hogy melyik zóna mit jelent és ott mi történik a szervezetben. Sokan vannak, akik még mindig a hosszú, lassú menés hívei (LSD - long slow distance) - ők általában nem szeretnek/tudnak keményen edzeni, viszont tengersok idejük van - én nem tartozom közéjük, illetve egyikünk sem, akinek limitált idő áll rendelkezésére az edzésre, mivel vannak más dolgok is az életében. A rossz hír a "lustáknak", hogy bizony minél nagyobb az intenzitás (anaerobot leszámítva), annál nagyobb adaptáció lesz a szervezetben - anaerob küszöb és maximális oxigénfelvétel környékén a legngyobb a kapillarizáció, növekszik a "stroke volume", javul a laktáttűrés, stb stb.
Lássuk tehát Dr. Coggan zónáit:

Coggan Power Levels

(Note: This article was authored by Dr. Andy Coggan and originally appeared on the Topica Wattage list forum)

As promised, here is the schema I've put together. In developing it, I've drawn from a number of sources,including Peter Janssen's book Lactate Threshold Training, Joe Friel's The Cyclist's Training Bible, the British Cycling Federation's training guidelines (developed by Peter Keen), in addition my own background in exercise physiology and experience of training and racing with a PowerTap the last couple of years. I would also like to recognize all the people who responded to my initial request for power data, as that has helped me to verify/refine the system. I'll begin by describing the various 'levels' in the system first, then discuss some of the details...

Level 1: Active recovery

Average power: <55% of 40k TT average power

Average heart rate: <68% of 40k TT average heart rate
Perceived exertion: <2

Description: "Easy spinning" or "light pedal pressure", i.e., very low level exercise, too low in and of itself to induce significant physiological adaptations. Minimal sensation of leg effort/fatigue. Requires no concentration to maintain pace, and continuous conversation possible. Typically used for active recovery after strenuous training days (or races), between interval efforts, or for socializing.

Level 2: Endurance

Average power: 56-75% of 40k TT average power

Average heart rate: 69-83% of 40k TT average heart rate
Perceived exertion: 2-3

Description: "All day" pace, or classic long slow distance (LSD) training (note that the "slow"� refers to the very high intensity, interval-centered training programs that were popular at the time the term was coined in the 1970's). Sensation of leg effort/fatigue generally low, but may periodically to higher levels (e.g., when climbing). Concentration generallyreq uired to maintain effort only during very long rides. Breathing is more regular than at level 1, but continuous conversation is still possible. Frequent (daily) training sessions of moderate duration (i.e., 1-2 h) at level 2 are possible (provided dietary carbohydrate intake is adequate), but complete recovery from longer workouts may take more than 24 hours.

Level 3: Tempo

Power: 76-90% of 40k TT average power

Heart rate: 84-94% of 40k TT average heart rate
Perceived exertion: 3-4

Description: Typical intensity of fartlek workout, "spirited" group ride, or briskly moving paceline. More frequent/greater sensation of leg effort/fatigue than at level 2. Requires concentration to maintain alone, especially at upper end of range, to prevent effort from falling back to level 2. Breathing deeper and more rhythmic than level 2, such that any conversation must be somewhat or very halting, but not as difficult as at level 4. Recovery from level 3 training sessions more difficult than after level 2 workouts, but consecutive days of level 3 training still possible if duration isn't excessive.

Level 4: Threshold

Average power: 91-105% of 40k TT average power

Average heart rate: 95-105% of 40k TT average heart rate
(may not be achieved during initial phases of effort(s))
Perceived exertion: 4-5

Description: Just below to just above TT effort, taking into account duration, current fitness, environment, etc. Essentially continuous sensation of moderate or even greater leg effort/fatigue. Continuous conversation difficult at best, due to depth/frequency of breathing. Effort sufficiently high that continuous cycling at this level is mentally very taxing - therefore typically performed in training as multiple "repeats", "modules", or "blocks" of 10-30 min duration. While consecutive days of training at level 4 is sometimes possible, in general such workouts should only be performed when sufficiently rested/recovered from prior training so as to be able to maintain intensity.

Level 5: Aerobic power

Average power: 106-120% of 40k TT average power

Average heart rate: >106% of 40k TT average heart rate
(may not be achieved due to slowness of heart rate
response and/or ceiling imposed by maximum heart rate)
Perceived exertion: 6-7

Typical intensity of longer (3-8 min) intervals intended to raise VO2max. Strong to severe sensations of leg effort/fatigue, such that completion of more than 30-40 min total training time is difficult at best. Conversation not possible due to often 'ragged' breathing. Should only be attempted when adequately recovered from prior training - consecutive days of level 5 work generally not desirable even if possible.

Level 6: Anaerobic capacity

Average power: >121% of 40k TT average power

Average heart rate: N/a
Perceived exertion: >7

Short (<3>

Level 7: Anaerobic power

Average power: N/a

Average heart rate: N/a
Perceived exertion: * (maximal)

Very short, very high intensity efforts (e.g., jumps, standing starts, short sprints).that generally place greater stress on the musculoskeletal rather than metabolic systems. Power useful as guide, but only in reference to prior similar efforts, not TT pace.

Discussion:

  1. Choice of 40k TT power as basis: Average power during a 40k TT provides a logical basis for a training system because it correlates very highly with power at lactate threshold, the most important physiological determinant of endurance cycling performance (since it integrates VO2max, the percentage of VO2max that can be sustained, and cycling efficiency). (Indeed, beyond the first few seconds of exercise the entire power-duration performance curve can be described quite closely using just two mathematical parameters, representing anaerobic capacity and lactate threshold respectively.) While shorter efforts might be more convenient, 40k was chosen because it is a standard distance and because power during a 40k is only slightly less than that generated during shorter TTs. In theory, one could derive specific correction factors to be used with data during shorter TTs (e.g., power during a ~20 min TT will be ~1.05 times that of a 40k) in order to fit such data into the system, but given individual variation in the exact shape of the power-duration curve, day-to-day variability in performance, and the breadth of the specified power levels, this may only convey a false sense of precision. Somewhat along the same lines, one could base a system on laboratory-derived measures, such as lactate threshold itself, but relatively few people have access to such measurements (as opposed to simply going out and measuring their own power during a TT). Conversely, one could dispense with using one single 'anchor' measurement, and simply reference all workouts back to the maximum power that an individual can generate for that duration (i.e., Friel's 'critical power paradigm'). However, such an approach requires much more testing than simply using TT power, while (in my opinion) providing little, if any, advantage in actual practice.
  2. Number of levels: A compromise had to be made between defining more levels, to better reflect the continuum of physiological responses, and defining fewer levels, for simplicity. The seven levels specified were considered the minimum needed to adequately describe the different types of training required/used to meet the demands of competitive cycling. Even with seven levels, though, the range within each is somewhat broad. However, this should not be a major disadvantage, for several reasons. First, there is obviously an inverse relationship between power output and the duration that power can be sustained. Thus, it is axiomatic that shorter training sessions or efforts will be conducted at the higher end of a given range, whereas longer sessions or efforts will fall towards the middle or lower end of a given range. Second, since power is a more precise indicator of exercise intensity than, e.g., heart rate, workouts should still be adequately controlled despite the seemingly large range in power within each level. Finally, as with all systems training exercise prescriptions should be individualized, in this case taking into account the power the athlete has generated in previous similar or identical workouts...the primary reference, therefore, is not to the system itself, but to the athlete's own unique (and current) ability. In this regard, the classification scheme described above should be viewed primarily as an overall
    framework, not a detailed plan.
  3. Heart rate guidelines: The suggested heart rate ranges must be considered as imprecise, because of individual differences in the positive y-intercept of the power-heart rate relationship. That is, even when power is zero, heart rate is not, with differences between individual in this 'zero power' (not resting) heart rate significantly influencing the percentage of 40k TT heart rate corresponding to any given power output. Because of this, I do not believe it is really useful to try to derive power ranges from heart rate ranges (as Friel's initial attempt to do so readily shows). (Expressing heart rate as a percentage of the range from that at zero power (derived by back-extrapolation of the linear power-heart rate relationship) to that at 40k TT power - akin to the Karvonen formula for heart rate reserve - corrects for this individual effect and allows you to more precisely specify the levels based on heart rate.
    However, I rejected this approach as simply being too complex, especially given that this is a power-based system.) Nonetheless, I have derived guidelines for heart rate (as well as perceived exertion) from power data, such that can be
    used along with power to help guide training.
  4. Perceived exertion guidelines: The values given are from Borg's 10 point category-ratio scale (reproduced below), not the original 20 point scale that is probably more familiar to most people. This choice was made because the category-ratio scale explicitly recognizes the non-linear response of many physiological variables (e.g., blood and muscle lactate), and thus provides a better indicator of overall effort.
        0 = Nothing at all
    
    0.5 = Extremely weak (just noticeable)
    1 = Very weak
    2 = Weak (light)
    3 = Moderate
    4 = Somewhat strong
    5 = Strong (heavy)
    6
    7 = Very strong
    8
    9
    10 = Extremely strong
    * = Maximal

    Since perceived exertion increases over time even at a constant exercise intensity (power), the suggested values or ranges obviously refer to perceived effort as determined relatively early in a training session/series of intervals.

  5. Other limitations: While the system is based on the average power during a workout or interval effort, consideration must also be given to the distribution of power within a ride. For example, average power during mass start races typically falls within the range defined as level 3 ('tempo'), but races are usually more stressful due to the greater variability (and therefore higher peaks) in power. Similarly, due to soft-pedaling/coasting down hills, the same average power achieved during a hilly (or even mountainous) ride will not reflect the same stress as the same average power achieved during a completely flat workout. In part, the variability in power is taken into account in defining the various levels, especially levels 2 and 3 (training at the higher levels is likely to be much more structured, thus tending to limit variations in power). Nonetheless, a workout consisting of, for example, 30 min at level 1 (as warm-up), 60 min at level 3, and another 30 min at level 1 (as warm down) would best be described as a tempo training session, even though the overall average power might fall within level 2 ('endurance').

One last caveat:

Defining various training 'levels' is obviously only the first step in developing a training plan, as what really matters is the distribution of training time or effort devoted to each of the various levels. Discussion of such matters, however, is probably best left to the future, so all I will say at this point is this: 1) I believe that training should be highly individualized, to account for each athlete's unique abilities, goals, and state of development (e.g., age, training background), and 2) compared to some, I tend to place more value in training at levels 2, 3, and 4 - indeed, what many consider to be 'junk training'. In that regard, my philosophy apparently parallels that of Peter Keen, or at least how his ideas are seemingly reflected in the BCF guidelines...

2009. augusztus 19., szerda

Zenészek és az ő Iphone app-jaik

Épp mikor újra gondolkozom zenélésben és nézelődök a színtéren, látom, hogy BT és Brian Eno Iphone app-okat írnak, amik kurva jók. Alapjában véve a Tenori-On ihlette ezeket a programokat, de mivel az igen drága játék, ezért lehet hogy megint Iphone-t fogok venni...?
Íme három remek app, köztük BT és Eno műve is:



2009. augusztus 14., péntek

Prodigy - Invaders Must Die

Ma a Szigeten PRODIDZSÁJJ..(nagyon gáz). Asszem harmadszor (vagy másodszor?) fogom látni és nagy tombolda lesz.
Az új albumon van pár remek dal: Omen, Take me to the hospital, Warrior's Dance, World's on fire - mindegyikben benne van a tipikus Liam-féle akkordozgatás, piliszkálás, oldschool szintihangokkal, mint az Out of Space-ben, viszont az alapok, amik sosem voltak soványok, most igen brutálisra sikeredtek. Nagyon tép, húz és harapdál, helyenként mert acélzene, tele iszonyat marós SID chipes lofi hangokkal.
Hallgasd meg ha akarod, de aztán töröld ám le, itt a link:
http://rapidshare.com/files/203332106/The_Prodigy-Invaders_Must_Die-2009-EOSiNT.rar

2009. augusztus 13., csütörtök

Neverending Story: Armstrong és a dopping

Az örök kimeríthetetlen téma. Bármelyik fórumon felmerülhet, garantált a több ezer hozzászólás vagy akár tízezer. Az egykor általam is csodált nagyon eredményes Lance Armstrong személyét ma már máshogy ítélem meg, mint régen, bár továbbra is óriási kerékpárversenyzőnek tartom, akármi is történt vele a kórházban - azonban hogy nem egy aranyember, az szinte biztos. Az alábbi linken egy olyan cikk található, ahol igazi bennfentesek ostorozzák egymást a kommentekben, ilyet nem nagyon lát az ember. Sally Jenkins, aki az Armstrong-könvyek szerzője volt, kap egy-két pofont Betsy Andreu-től, Frankie feleségétől (ex-USPS csapattárs és barát) a bátor asszonytól, aki tanúskodott, mint jelenlevő szem- és fültanú, hogy Armstrong elismerte tiltott szerek használatát abban a bizonyos korházi szobában 1996-ban az orvosa erre irányuló kérdésére.

Cikk

Eredeti sztori

2009. augusztus 12., szerda

Egy igazi kincs: Vive Le Tour (1962)

A velora postázta valaki ezt a kisfilmet, ami 1966-ban készült és nem akárkik készítették: Louis Malle szemszögéből George Delerue zenéjével kísérve láthatjuk a Tour gyönyörű és fájdalmas pillanatait, illetve pár olyan jelenséget, ami ma már nem látható profi kerékpárversenyen, mint pl. italozgatás sisak nélkül a motoron, útszéli kocsmák lerablása, amiért utólag számláz a tulajdonos, megállás, fürdőzés és hihetetlen tologatóverseny az emelkedőkön.
Ez a kisfilm a legprofibb film, amit valaha láttam kerékpáros témában, másodikként az Overcoming-ot említeném, aztán nagyjából ki is fújt.