5 K Jog + Interval Training

Today is my regular day off.
I slept late at a hotel in Yokohama, strolled along the Isezakicho Mall,
had lunch at Nepalese restaurant Safari in Kannnai,
and had dinner at steak restaurant Pepper Lunch in Sakuragicho.
Having fully charged my body's batteries,
I hit the road after coming home.
I jogged 5 K for warm-up,
and after that did alternate runs for twenty minutes.
The latter is a kind of interval training.
You jog for one minute and run fast the following one minute.
I did it ten sets today.
Together with the 5 K jog that preceded it,
I ran about 9 K in 44:48.50.

The details of today's training are as follows:
1st 2.5 K: 12:41.72
2nd 2.5 K: 12:05.31
Interval training: 20:01.47
Total 9 K: 44.48.50

Ever since I ran Sakura Asahi Kenko Marathon 2017 on March 26,
I haven't run farther than 9 K.
This is mainly because my focus is on running form.
The past running season brought me a new running experience.
The most important element in the change is shoes:
split-toe minimalist running shoes MUTEKI.
The shoes have allowed me to acquire something called "Nanba Souhou"
where forward movement is created not so much by the kick of your leg, but rather by the shift of your weight.
The biggest benefit of this running form is that energy loss is minimum,
so there is a big advantage when the distance is long.
In fact, the benefit is proven in a short distance race.
200M finalist Shingo Suetsugu got a bronze medal in IAAF
World Championships in Athletics in Paris
by running in Nanba Souhou.
I watched his documentary, and have learned
that two factors are important in getting most out of this strategy.
One, you move forward not by the kick but by the shift of weight.
Two, you land on the whole of your sole to maximize repulsive force.
When I ran tonight, I did my best to adjust my form to realize what I learned from the video.
It seems hard to know if you are doing the right thing or not.
But in fact you can fairly easily tell that.
When you are doing the right thing, you feel light,
and you continue to feel light throughout the entire fast run session in the alternate runs.
On the other hand, when something is off, you can easily get exhausted.

It was my first time to combine regular running and interval training.
I would usually do either one of them, and not both.
But I kind of like it.
Sometimes you don't feel motivated enough to do a 50-minute interval session,
but still want to do something focusing on speed.
But you also want to run a certain distance at a steady pace that's not too challenging.
What I did today answers both of these needs.
I may do it more often during my off season.