A．Wearing arm weights while you are swimming.B．Jogging vigorously in one place for a long time.C．Using bicycles that require you to use both your arms and legs.D．Walking slowly while swinging your arms back and forth.
A．Wearing arm weights while you are swimming.
B．Jogging vigorously in one place for a long time.
C．Using bicycles that require you to use both your arms and legs.
D．Walking slowly while swinging your arms back and forth.