According to some estimates, Americans work about 200 hours more per year than they did in 1970. When you factor in a shaky economy and worries about job security, the workaholic trap is easy to fall into. But there are two steps you can take to sidestep it.
First, find out which tasks are the most important to your boss. Many workaholic bosses won't prioritize which items need to be done first. This forces employees to work around the clock on every assignment at once, guaranteeing that few are done well. So it's wise to approach your boss regularly with the current projects on your slate and get a definitive answer on which ones take precedence over others. Meeting the deadlines on those projects and delivering satisfactory results will prove to him that prioritizing them was the right approach.
Second, set boundaries between your personal and work life. It's important to cordon off your home life from your work life to avoid the seemingly cyclical workaholic lifestyle. Tell your boss that you will not answer emails or messages of any kind during the usual off-work hours unless they're emergencies. It may not prevent your boss from feeling that you don't work as hard as he does, but it will help keep you from returning to the never-ending 24/7 grind.