1. "You must run all the time."
Although this may seem true, it's not. Marathon runners do not run high mileages every week, as this can lead to injury. Instead, they build up to key races, tapering at times with reduced miles.
When not training for a race, marathoners may reduce their miles to give their bodies a rest before building back up again. Training may involve a long run on the weekends, with days off, easy recovery runs, and speed work during the week.
Long runs can take anywhere from two hours to five hours. During the week, shorter recovery runs may only be 30 minutes to one hour. Long distance runners don't run "all the time."
2. "You must lose a lot of weight."
Actually, some people gain weight during training. There's something about long runs that trigger your appetite. Plus, marathon runners may take in more calories after a workout to reward themselves.
Overall, marathoners know their bodies very well. They seem to be able to eat just the right amount of food and maintain their weight even through heavy training periods.
3. "You must be really fast if you can run that far."
There are those who are gifted enough to be able to run far and fast, but not everyone can. For a marathoner, building up endurance is usually more important than building speed.