As a weekly runner of over 50-60kms a week i understand now that endurance sports have a funny way of making you irritable.
The cyclist may have ridden over 200Kms and have spent 3-4 hours in the sun.
Unfortunately he/she will take on anyone that gets in his way.
Cyclist don't like runners as well.
Some weekends i may run a 1/2 marathon but dont realise how irritable i get. I have to remind myself constantly if my brain isnt too fried from being in the sun for 2-3 hours of high intensity effort.
