In a 50-Minute Alternate Run you have two kinds of runs alternately.
One is a one-minute fast run. And the other is a one-minute slow jog.
Together they make one set taking 2 minutes.
In 50 minutes you can repeat this 25 sets.
I learned this training from "Running with the Kenyans" by
British author Mr. Adharanand Finn
who is a runner himself.
I'm doing it for the first time tonight.
I came back from the training around 1:30 a.m.
The 50-minute alternate run was a very challenging,
and very exciting session.
As far as the total duration of training time goes, it is almost the same as
1K by 7 sets interval training with a two-minute rest between sets.
Which is more challenging?
It's hard to compare.
In the interval training, you keep a fast pace for almost four minutes.
But the rest is longer: two minutes.
In the alternate run session a fast run last only for one minute.
Much shorter than the fast run session of the interval training.
But the rest is active and shorter: one minute.
It apparently seems easier if you compare the length of the fast session itself.
But the truth of the matter is that in the latter your pace is faster for the entire one minute.
On the other hand, in the interval training, you can fatigue as you go on,
so toward the end of each 1 K run, you come to slow down slightly.
One thing I can say about the alternate run is
that you have a sudden change of pace 25 times.
I don't know how this affects my performance during a full marathon.
I am curious to see how it translates into better performance when I run on March 26.