descending ladder
hard efforts of 3:00, 2:00, 1:00, 0:45, and then 0:30 repeated to exhaustion,
with recovery jogs of two-thirds the duration of the previous hard interval
也就是说3分钟all out, 2分钟easy,
2分钟all out,75分钟easy
1分钟 all out,40 秒钟
然后30秒钟一直到力竭。看着有点恐怖,要不要你来edit一下,哈哈