Longer intervals. 9th and 10th run together, total of 7 minutes + 30 seconds from cooldown.
Lower abdominal dull pain started after 4th interval, but it was not that bad. I did not feel it a lot during running, but the pain continued after the run and the following day. It is not as bad as it used to be, but it is still pain. I should give it more time to heal.