Grab three-pound weights or two soup cans and do one minute each of lifting for your triceps (put your hands behind your head, with your elbows at your ears and lift the weightup and down).
手握三磅重的东西或者2个汤罐头，锻炼双臂肱三头肌，（把手放置于后头，手肘靠近耳朵，上下举起负重）。
3
With every stride, runners hit the ground with up to five times their body-weight.