The group A was subjected to twice treadmill exercise tests(TET) at the interval of 10 minutes but group B did it at the interval 30 minutes according to Bruce protocal.

• 按修定的Bruce方案 ,A组于首次活动平板运动试验 (TET)后 10分钟行第二次TET ,B组于首次活动平板运动试验后 30分钟行第二次TET。