The problem is that at EK you are doing both at the same time... "Loco" turnaround one day, the next day a longhaul flight involving different time zones, the next day another turnaround followed by minimum days off and then a ULR... Etc.
And that is what is punishing and taking its toll on the body and your home life.
Like oddins, I have done both for a considerable time and this is far more difficult on the individual.