I would say no. Cognitive Dissonance is more about someone saying they believe something but then their actions don't reflect that belief.

An area of Cognitive Dissonance that I have, I know that I need to take more consistent breaks from computer work more often to prevent pain from repetitive stress injuries, But I don't.

Your description is not quite right: https://en.wikipedia.org/wiki/Cognitive_dissonance

Your example is not cognitive dissonance. To be that, not taking the breaks would have to go against a deeply held belief, and make you feel uncomfortable.

The term itself is concerned more with a person's own experience of the world. What you're describing, i. e. his actions/words as observable by others, is probably closer to 'hypocrisy'.

"Cognitive dissonance' is far less judgemental–its considered to be an essential mechanism of learning.

Akrasia is a good word for this concept.

aka "Practice what you preach?"