Is it possible to prepare a race just by using the treadmill, without running outdoors? How to prepare it can be done, but let’s say that it’s not recommended to prepare a race with this method alone.
The reason is simple: the conditions on the treadmill are not going to be the real conditions you find yourself in the race; neither the same type of stride nor the same joint impact, different weather, different muscle work, changes of direction that do not exist on the treadmill?
Someday we can train on the treadmill, that’s why there’s no problem, both in some filming and in series work, but surely if that same day you go out to run you’ll notice that the sensations are very different.
It’s also very tedious to train on the treadmill, it becomes very boring compared to the outdoors where we have more distractions, a changing route and in general, the time and the perception of effort become less. Many long distance runners use the tape for psychological work for this reason.
And if the race we want to prepare is long distance, half marathon type or more, with more reason we have to avoid using only the treadmill, because our stride and muscle work in the race must get used to the terrain in which we will compete.
In conclusion, do not use the treadmill as the basis of your training in the race: use it more as a complement to your training for days with bad weather, when you want to do series at a certain speed or to play with the inclination in some training.