빠른 움직임이 필요한 운동선수는 fast twitch fiber가 주로 동원되는 eccentric exercise를 해야

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간단하게 정리하면 

구심성 수축을 할때 모든 근육이 동원되고, 원심성 수축을 할때 type 2(fast twitch, 속근 사용)

그래서 빠른 움직임이 필요한 운동선수는 fast twitch fiber가 주로 동원되는 eccentric exercise를 해야

- 문제는 이때 DOMS가 잘 발생한다는 사실.

- DOMS를 예방하고 치료하기 위해서는 적절한 얼음팩과 스트레칭을 시행하면 좋을 듯

Concentric & Eccentric Contraction

Concentric contraction occurs when a muscle shortens in length and develops tension e.g. the upward movement of a dumbbell in a biceps curl or as you spring back from a jump landing, extending your knees and jumping back up in the air, the quadriceps are shortening as they create force to push you off.

Eccentric contraction involves the development of tension whilst the muscle is being lengthened e.g. the downward movement of a dumbbell in a biceps curl or when you land on two feet from a jump and bend your knees the quadriceps are lengthening.

Eccentric movements recruit most fast twitch fibres

Research, McHugh et al. (2002) [1], investigated the difference in activation patterns between eccentric and concentric quadriceps contractions. The researchers measured the amount of muscle activity as revealed by electromyography (EMG) and the mean frequency of the EMG signal. As a rule, the larger the EMG signal recorded the more muscle fibres are being recruited, while the frequency of the signal is an indication of how fast they are being recruited. Research has shown that higher frequency EMG is consistent with greater fast twitch fibre recruitment.

They found that the total EMG signal was greater during the concentric phase, suggesting more muscle fibres are active at this time, while the mean frequency of the EMG signal was greater during the eccentric phase, suggesting more fast twitch fibres are being recruited at this time. 

실험결과 원심성 수축이 일어나는 동안(빠른 수축섬유가 동원되는 동안) 근전도 신호가 커짐.. 

They concluded that during a maximal eccentric contraction there is less total muscle fibre recruitment, with fast twitch fibres recruited in preference to slow twitch ones, whereas during a maximal concentric contraction all the muscles fibres are used.

This finding is significant for power athletes as the research suggests that if you want to train your fast twitch fibres it would seem that eccentric contraction movements are more useful than concentric ones. Plyometric exercises, which involve high-force eccentric movements, would be particularly useful for this purpose. A good example is the depth jump, which involves jumping off a box, bending at the knee and hip to control the landing softly, then jumping back up. Power athletes may also want to consider performing strength exercises using the eccentric phase only. By this means you may be able to target just the fast twitch fibres and perform less total work, potentially making the training more efficient. You will need a training partner or coach to assist you with each concentric phase, leaving you to complete the effort on each eccentric phase alone.

Delayed Onset of Muscle Soreness (DOMS)

Muscle soreness that occurs some 24 to 48 hours after intense exercise usually involves eccentric contractions. This causes increases in intracellular pressure that irritates the nerve endings, producing swelling and local pain. The soreness can be an indication of potential muscle adaptation to follow, but if it persists or is debilitating then it could indicate over training or large muscular tissue damage.

An appropriate warm up and cool down may help to avoid or reduce DOMS.

[최대석]

감사합니다.
안그래도 이런 운동을 하고 있는데 왜?란 질문을 많이 받았는데.
근데 운동을 해보니 저항이 강도 움직임의 포지션에 따라 원하는 근육에 등척성 수축을 일으키는게 쉽지는 않는것 같아요.
ㅜㅜ

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원심성 수축일때 훨씬 힘이 발생함.