Which comes first? Speed or endurance? At the end of May, I want to be running 10km in 70mins. Today, I ran 7.25km in 56mins. Which would equate to 10km in 77mins. Should I concentrate on building up my distance and then start seeing what I can shave off the time, or should I concentrate on shaving off the time and then building up the distance? Or is there a way of doing both at the same time?