There is plenty of evidence that excessive working hours can cause sleep loss, fatigue and stress, and that long hours and shift work are associated with higher levels of heart disease. General performance is poorer at night and fatigue is likely to be a cause of accidents at work.
Long hours are also detrimental to family life. As you say, the majority of those working very long hours are men, which means that they are less likely to spend time with their children or take their share of domestic responsibilities. Average working hours in the UK have been rising at a time when average hours across the rest of the EU have been falling. More than three million men, nearly a third of full-time male employees, now work over 48 hours a week, compared with 2.4 million in 1984.
I would attribute this less to macho culture than to the pressure put on employees. TUC surveys consistently show that most men would like to work shorter hours. This is hardly surprising given that many people believe that the job they do today would have been done by two people a decade ago. And contrary to your comments, the market does not currently provide a sanction against exploitative employers.
Employees in today's changing labour market do want a life outside work. The implementation of the Working Time Directive will help, limiting to sensible and safe levels the number of hours employees can work, introducing proper rest breaks, and, for the first time in Britain, a legal right to paid annual leave.
Trades Union Congress