We perceive other levels of honesty and moral uprightness based on their actions (words and deeds). People who do not follow through can lose respect and trust very quickly.
That is not to say you must accomplish every objective and goal you expound on in order for others to view you as having a high level of integrity.
Open, Clear, and Forthright
Things change and new circumstances may make if less feasible or even impossible for you to complete your initial commitment (i.e., you said it but could not do it.)
However, when what you committed to changes, openly communicating this, and discussing options with those impacted mitigates your risk of being perceived as dishonest.
Blindly Forging Ahead
Making a personal commitment does not entail being successful at all costs but collaborating with others to achieve positive outcomes when the unforeseen occurs is critical.
Blindly forging ahead with your initial approach when it has become unfeasible can be both painful and unproductive. Our moral foundation will not be cracked because we fail, only if we ignore that failure and hide it from others.
Explore Alternatives
When I was young my parents use to advise me; Succeeding is important but trying is critical. If we have accepted accountability for a task or deliverable it is possible we won’t achieve it.
This does not impinge upon our integrity as long as we both tried and kept everyone who will be impacted apprised of our efforts and well as consulting them and seeking assistance where it makes sense.
Maintain your personal integrity with others – try your best and keep them informed.