No. Most structured training plans will emphasize different physiological systems at different times. Typically they will start with low aerobic in the opening weeks, then add in more high aerobic, and then some anaerobic much closer to the event.
Also, the mix is going to be different for different events - a 5K program will have more high aerobic and anaerobic work than a half marathon program, which will be more based around low aerobic and high aerobic work.
