chances are your extracurricular (home sporting) activites are helping actually helping you by raising your T-Levels. Making you more agressive on the field.
Have you considered that you're just getting better at the running? You're giving it all you've got which is more then what you had, and this is why it is not getting easier, you may in fact be working harder. Just consider that!
NOTICE: Pierre Auge's opinions are subject to change at any time and without prior notice.
To give real service you must add something which cannot be bought or measured with money, and that is sincerity and integrity. - Douglas Adams