Learn Hardcore German: Ich brauche das Training, um fit zu bleiben.

In German, subordinate clauses—including purpose clauses introduced by um … zu—must be separated from the main clause by a comma. Here um fit zu bleiben is a purpose clause (“in order to stay fit”), so it takes a comma before it.

What does the um … zu construction mean?

The um … zu construction expresses purpose, equivalent to English “in order to.” You use um + infinitive clause with zu before the verb to say why something is done.

Why is the verb zu bleiben and not just bleiben?

In an um … zu clause the main verb is an infinitive and must be preceded by zu. German places that zu immediately before the verb, and the entire infinitive phrase goes to the end of the clause.

Why is das Training in the accusative case?

The verb brauchen is transitive and needs a direct object. In German, direct objects take the accusative case, so das Training (neuter noun) is accusative here.

Why is fit not capitalized?

In German, only nouns are capitalized. Here fit is used as an adjective (predicative, describing your state), so it remains lowercase.

Could I say Ich brauche zu trainieren, um fit zu bleiben instead?

No—brauchen + zu + infinitive normally appears only in negative or interrogative sentences (e.g. Du brauchst nicht zu kommen). In affirmative statements you either use brauchen with a direct object (as here) or a modal verb like müssen plus an infinitive.

Can I omit das and say Ich brauche Training, um fit zu bleiben?

Yes. If you mean training in general (uncountable), you can drop the article: Ich brauche Training, um fit zu bleiben. It’s still correct and common.

Can I say Ich muss trainieren, um fit zu bleiben instead?

Absolutely. Ich muss trainieren, um fit zu bleiben means “I have to train in order to stay fit.” Using müssen focuses on your need to perform the action, while Ich brauche das Training emphasizes that the training itself is what you need.

Can I move um fit zu bleiben to the beginning of the sentence?

Yes. If you start with the subordinate clause, you must invert subject and verb in the main clause:
Um fit zu bleiben, brauche ich das Training.