First run after Marselis run

Yesterday evening I went for a run. In the beginning, I ran with a high intensity but I could not keep that the rest of the route due to "sidestik". I don't know why I started to get this but one of my colleagues have told me that stomach crunches should eliminate them.

The trip was fine and no rain. It's getting colder though.. brrrr.

Distance: 7.7 km
Avg. speed: 13.2 km/h
Avg. pulse: 156