This via Making Light:
Reading worked best, reducing stress levels by 68 per cent, said cognitive neuropsychologist Dr David Lewis. Subjects only needed to read, silently, for six minutes to slow down the heart rate and ease tension in the muscles, he found. In fact it got subjects to stress levels lower than before they started.
Listening to music reduced the levels by 61 per cent, have a cup of tea of coffee lowered them by 54 per cent and taking a walk by 42 per cent. Playing video games brought them down by 21 per cent from their highest level but still left the volunteers with heart rates above their starting point.
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