De or het dinsdagtraining?

The correct Dutch article is:

de dinsdagtraining

Rule Words ending in -ing: almost always de. See the rule

How to use dinsdagtraining

the dinsdagtrainingde dinsdagtraining
this dinsdagtrainingdeze dinsdagtraining
that dinsdagtrainingdie dinsdagtraining
our dinsdagtrainingonze dinsdagtraining
your dinsdagtrainingjouw dinsdagtraining
every dinsdagtrainingelke dinsdagtraining
which dinsdagtraining?welke dinsdagtraining?
a big dinsdagtraining / the big dinsdagtrainingeen grote dinsdagtraining, de grote dinsdagtraining