De or het trainingsbelasting?

The correct Dutch article is:

de trainingsbelasting

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

How to use trainingsbelasting

the trainingsbelastingde trainingsbelasting
this trainingsbelastingdeze trainingsbelasting
that trainingsbelastingdie trainingsbelasting
our trainingsbelastingonze trainingsbelasting
your trainingsbelastingjouw trainingsbelasting
every trainingsbelastingelke trainingsbelasting
which trainingsbelasting?welke trainingsbelasting?
a big trainingsbelasting / the big trainingsbelastingeen grote trainingsbelasting, de grote trainingsbelasting