Fartlek: 4 Sets by 650 M @ 2:36 (=4:00/K Pace)

May 22, 2019
650 M: 2:22.74 (target: 2:36=4:00/K)
Active rest (jog): 1:02.83
650 M: 2:41.77 (target: 2:36=4:00/K)
Active rest (jog): 1:30.86
650 M: 2:31.55 (target: 2:36=4:00/K)
Active rest (jog): 1:30.30
650 M: 2:31.55 (target: 2:33.96=4:00/K)
Active rest (jog): 2:02.24
Total 2.6 ~ 3.5 K: 16:16.25

While I was browsing through Facebook, I came across a variety of fast-paced interval sessions called fartlek done by men's marathon world best record holder Eliud Kipchoge and his teammates. I found them inspiring, so I immediately came up with my own training regimen based on my present capacity and goal. It's a 650 M fast run @ 2:36 (4:00/K pace) repeated 15 times.

I wanted to put my ability to the test right away, so as soon as I got home, I changed into my athletic gear and hit the road. 

I skipped warm-up jog, and only did jumping jacks and high knees to warm up. Once it's done, I set off for the first set. It's been a while since I last aimed at 4:00/K pace, so I wasn't sure how fast I was going, but I WAS sure I was going a lot faster than usual. Halfway though, my legs started feeling heavy from oxygen debt. Breathing was hard too. I saw my watch to check my lap. 2:22.74. Almost 14 seconds faster than the target. No wonder it was tough.

I jogged for a minute and ran fast again. This time the lap was  2:41.77. I paid the price for going too fast in the first set. 

When the second set was over, I was so bonked out that I couldn't go on without taking a longer active rest. I jogged a minute and a half, 30 seconds longer than after the previous set. 

Thanks to the longer recovery time, my third lap was 2:31.55, a few seconds under the target. 

Feeling confident that this combination of pace and recovery time may be sustainable, I went for another set to run it in 2:33.96. Again, I made it under the target. 

However, when the fourth set was over, I had to admit to myself that I was burned out for the day. 

Next time I do this training, I will probably work with a 90-second rest right from after the first set to make it sustainable 15 times.