I've just hit my goal of 5k with a 6min/km pace. I've noticed my legs were fine and my main difficulty was having enough breath to survive 30 minutes.
My race prediction for 5k is 21 minutes, which I feel is impossible at my current training condition. But I guess that, as my VO2Max is 54 (and I did medical exams that got the same result), I could reach this goal someday with the right training.
Do you have any tips of what training could help me to improve?