Time Spent Learning and Performance

While researching performance, motivators, and productivity I found an interesting article that I thought I would share. It is geared towards scientific and creative endevors and not necassarily a fix all in all industries but it seems sound advice for students. The theory is that four hours a day will produce the most effective, productive and focused perfomance/productivity. The article states that "scientists working 35 hours a week were half as productive as their 20-hours-a-week colleagues".  

Do you think it could also apply to training in the workplace? I don't know about anyone else but to sit through an eight our training session for me is excruciating and I do not beleive I would learn more in an eight hour session than in two to four hour increments. When I study I try to keep it to around 3 hours a day. What timeframe works for you?  

http://theweek.com/articles/696644/why-should-work-4-hours-day-according-science