I dont know... When I still smoked and was a beginner runner, I always felt wrong after having a cig before or after a run. Not only mentally wrong but physically too. A guilty feeling. I wanted to give up so badly but just did it because it was a habit.
I remember the mornings waking up and having dry mouth and throat...ewww!!!
Running gave me courage to have all or nothing approach. I remember when I put down my last cigarette I felt relief knowing it was the last one.
There has been only one occasion since when I nearly had one. I was a bit intoxicated with alchol and my friend was smoking and offered me one.
I thought about it for 10 seconds or so and just realised that I know what it tastes like. Nothing new there. Nothing exciting. Done it for 10 years. I dont want it anymore. I am a runner and I love being healthy.
And I knew that was my last test.
What comes to my performance... Well I've ran a marathon. I'm still not a fast runner but... I'd rather run a marathon than TRY to run a marathon with tar in my lungs!