Q: how many kilos in a 5 k run

A: Well, 5k means 5 kilometers. If you meant how many miles in 5k, then the answer is just over 3 miles. And if you meant how many kilograms of mass you'll lose after a 5k run, then the answer is very very little (less than a tenth of a kilogram), not counting the water lost through sweating which will be replenished quickly. If you're thinking of running a lot of 5k races to lose fat, then I urge you to read this first.