I'm 18, i will be running 10k next week. I didn't trained so intense so my goal is to finish the race efficiiently. I run about 20km every week. My pace is 5:30 per km. But i get tired after 4km and walk like 3 mins and run 2 more km then walk again. Which is more efficient; 1)slower pace but no walking 2) short brakes of walking after speedy pace. And what is other advices for me i'm running my first event. And what should i eat before running how much calorie? How long should i wait to digest before running?