Work time regulations have the potential to have an important impact on work-life balance and wellbeing in medical education and graduate training. However, work-time is only one factor in a complex system.
The 2012 report by Morrow, Burford, Carter and Illing gives a good overview of the issues of trying to implement an initiative into a complex setting.
One of the implications is that stressors like working hours have both an absolute effect but also have complex implications for identity and work-team unity that also have wellbeing implications.