V02 max Interval workout :1200m repeats

This morning I woke up at 5:20 a.m. sleepy eventhought I went to bed last night at 10:30 a.m., but anyway at 5:40 a.m. I went out to do my v02 max interval workout today, it was 4 x 1200m with 4 mins rest, I wanted to run sub 4 mins per km. I warmed up with Danilo 3k to the mirador in 19:20 or so and as usual had stomach problems, thanks goodness that that didnot get worse in the workout, then stretched a bit before starting the workout. The first repeat started, I did it with urraca, I went out at a good pace, after 500m my breathing was fast, but urraca's breathing was pretty controled. We crossed the 1k mark in 3:51 and hit what I thought was the 1200m mark in 4:44, I suspect that I ran a bit longer than 1200s. I stopped for my recovery and urraca kept on, the second repeat was till the 0km, this one was in 4:46, I dont know if this was longer, the 3rd repeat was the same as the first, till the puente seco or so, I crossed the 1k mark in 3:49, I saw Danilo in this repeat and I was very focused and the breathing was very fast,I could maintain the pace but it was no close to easy, and ended doing 4:38, again a bit longer I think, the last one was like the second one, with 500m to go I was really tired and the breathing was very fast, I could charge the last 150m to finish that repeat in 4:45. 3k cool down. The weather was very hot, I was soaked of sweat when I got to my house. I am satisfied with the workout, but would like to feel more confortable at that pace. The left foot did not bother me at all today.

12.7k or so total, around 72 mins.