Which of the following contributes to breakdowns in hygiene practices?

Neglect of personal duties directly contributes to breakdowns in hygiene practices because it involves an individual's failure to perform necessary daily tasks related to cleanliness and self-care. When someone neglects their personal hygiene, it can lead to a variety of health issues, both for themselves and for those around them. This neglect can stem from a lack of prioritization regarding hygiene practices, often leading to a cascade of negative effects within a unit or team.

In contrast, other factors like lack of communication, overtraining, and excessive fitness standards might create environments that don't support hygiene practices effectively, but they do not directly influence an individual's personal responsibility regarding hygiene. For example, while overtraining might lead to fatigue, preventing someone from maintaining their hygiene, it is not the failure of hygiene practices itself. Likewise, lack of communication may lead to confusion about hygiene expectations, but again does not directly result in neglecting hygiene duties.