You could just go out and buy a new shorter pair of laces, but first why not try this.
Unlace to the bottom and pull out a loop of about 3 inches.
Make a knot.
Take right lace over the loop piece and into left eyelet.
Same with the left - take left lace over the loop piece and into right eyelet.
Now right lace into left, left lace into right.
Take right lace through the middle of the loop and into left eyelet.
And left lace through the middle of the loop and into right eyelet.
Hopefully this makes sense. Now you can just go out running for the fun of it and not to the store to buy new laces.