Absolutely. 'Moving the needle' doesn't require long days, instead it requires discipline an focus on doing the one thing that will move your project forward. From experience at large companies I think most people waste 4 to 6 hours a day in pointless meetings, dealing with low ROI work items or looking at Facebook. Some of the self-made wealthiest people I know certainly didn't work 8 hours every day to get there, instead they were focused and masters of delegation and emotional intelligence.