The MD/MPH program at my school is NOT one year actually. At UMDNJ, you can start the summer before med school and take two MPH classes. Then you take one MPH class your 1st semester. And your first summer, you take another 2 MPH classes. Then I think you take 1-2 more MPH classes in your second year.
After your second year of MD, you take one year (summer, fall, spring, summer) off to solely pursue the MPH program. When you are done, you then continue with your MD.
Though, one year is dedicated to MPH study, you are taking MPH classes all the while, they just give you a year to get into the nitty gritty stuff. Even if you do the 2 year programs outside of MD, the first 12-15 credits are basic stuff before you get your nose in the dirt. The "nose in the dirt" part is your year off (if you choose to go the MD/MPH route).
Thats my take on it.
Yeah I can't intern or go off on my own to get some hands on experience, but I wouldn't be able to do that regardless because I can't quit my job (I have obligations) to go off on an MPH internship experience elsewhere.