英文字幕:
Swimming. A race for glory. A fight against physics.
Hi, I'm Dr Greg Wells. During a race, swimmers are battling more than just each other. The other opponent: water. A substance 800 times denser than air. It creates massive resistance, or drag. It's the swimmer's worst enemy.
Here's how they cut through it, and get maximum propulsion. To move themselves down the pool, Olympic swimmers don't just slice and pull straight back. They angle their hands and forearms to flow through the water and create lift. Basically, they turn their hands and forearms into propeller blades. So their shoulders get incredibly strong. They develop powerful rotator cuffs to control the shoulder and lats to transfer the power from the hands, through to the body.
Moving through the water at Olympic speed makes their muscles activate like crazy. This produces carbon dioxide, which is the body's exhaust. Muscles dump carbon dioxide into the blood, which turns the blood acidic. Our carotid arteries have chemoreceptors that sense if acids are building up. They send urgent warnings to the athlete's body: breathe, or suffer a meltdown. But Olympic swimmers can't breathe whenever they want. They can only inhale in time with the stroke, and they have to hold their breath when they push off the wall under water. So they train to desensitize their chemoreflexes and suppress the urge to breathe.
Slice through the drag...And make each breath count like it's your last. That's how you go from the pool, to the podium!
中文字幕:
游泳,争取荣誉的比赛,对抗体能的争斗。
我是维尔斯博士。游泳选手在比赛中不仅要对抗其他选手,还要对抗水。水的密度比空气大800倍,能形成巨大的阻力或拉力,是选手最大的敌人。
选手是这样切入水中,并获得最大推动力。要在泳池中前进,奥运选手不光是把水往后拨,他们把手和前臂以某角度穿入水中来制造浮力。基本上,他们把手和前臂变成螺旋桨,所以他们的肩膀异常强壮。他们练出强大的肩袖来控制肩膀和背阔肌,从而把力量从双手传到全身。
以奥运速度在水中前进,需要他们的肌肉不停活动。这会排出二氧化碳,也就是身体的废气。肌肉把二氧化碳排进血液,使血液变成酸性。颈动脉有化学感受体,可以感知酸的增加,于是便警告选手的身体:“快呼吸,不然身体会失灵”。但游泳选手不能随意呼吸,他们只能配合划水的动作吸气,而且在水中推进时要闭气。因此他们通过训练,来钝化化学感受体,压抑呼吸的欲望。
切开水的拉力,把每下呼吸都当成最后一口,这就是通往领奖台之路。
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(Video provided by GE 编辑:Julie)