In the next stage—REM sleep—we begin to breathe faster and our eyes move around quickly, but our bodies do not move.

下一个阶段又称为快速眼动睡眠阶段，我们的呼吸开始加快，眼球也开始快速跳动，但我们的身体却保持不动。

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From that moment on the Up keeps extremely close tabs on your movement using actigraphy to tell when you've fallen asleep and whether you're in a deep REM stage or lightly snoozing.

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Alcohol reduces how much time we spend in rapid eye movement (REM) sleep - the stage of sleep where dreams generally occur.

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Excessive alcohol consumption disrupts the 'REM' (Rapid Eye Movement) stage of deep sleep to ruin a night's rest, according to the UK Department of Health.

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