A lot of people will just start into a major workout and end up cutting it short because their muscles can't do it. Take a pickup basketball game. Task-oriented people work out to master an exercise. This type of person doesn't necessarily work out to lose weight or become an ber-athlete. Instead, they take pride in the process of becoming more healthy and changing their lifestyle.
Weekend warriors fall into the ego-driven orientation group.
Or they will develop an intense focus on losing weight. They'll work out all weekend, not eat and get sick from not keeping up proper nutrition or they'll hit a plateau, get frustrated and quit. Ego-driven people often don't set reasonable goals, or expect that such goals can be achieved in a very short time frame. Many weekend warriors will claim that they just don't have the time to work out during the week. But then when they really examine how they allocate their time, it can be quite interesting.