Treningsplanen fungerer, bare hviledagen beholdes.

Because Norwegian very often forms compound nouns as one word.

• treningsplanen = treningsplan

  • -en
  • trening = training
  • plan = plan
  • so treningsplan = training plan
  • -en makes it definite: the training plan

• hviledagen = hviledag

  • -en
  • hvile = rest
  • dag = day
  • so hviledag = rest day
  • -en makes it definite: the rest day

This is very normal in Norwegian. English often writes these as two words, but Norwegian usually joins them into one.

The ending -en is the definite singular ending for many masculine nouns.

So:

• en treningsplan = a training plan
• treningsplanen = the training plan

and:

• en hviledag = a rest day
• hviledagen = the rest day

In this sentence, the speaker is talking about a specific training plan and a specific rest day, not just any plan or any rest day.

Fungerer is the present tense of å fungere.

• å fungere = to function / to work
• fungerer = works / is working / functions

So Treningsplanen fungerer means that the training plan works or is working.

In Norwegian, the present tense is often used in ways that English might translate as either simple present or present progressive, depending on context.

Here, bare means only or just.

In this sentence, it limits hviledagen, so:

• bare hviledagen = only the rest day

That means the second clause is saying that the only thing being kept is the rest day.

The subject is bare hviledagen.

That may feel unusual to an English speaker, but here bare is part of the noun phrase:

• bare hviledagen = only the rest day

Then the verb is:

• beholdes = is kept / is retained

So the structure is basically:

• [Subject] bare hviledagen
  • [Verb] beholdes

This is why the word order is natural in Norwegian.

Because beholdes is passive.

• beholder = keeps / retain(s) → active
• beholdes = is kept / is retained → passive

It comes from the verb å beholde = to keep / retain.

So:

• Vi beholder hviledagen = We keep the rest day.
• Hviledagen beholdes = The rest day is kept.

The passive is used here because the sentence focuses on what is kept, not on who keeps it.

This sentence uses the -s passive, which is common in Norwegian, especially in written or concise style.

From the infinitive:

• å beholde

you get the passive present:

• beholdes

So:

• hviledagen beholdes = the rest day is kept

Another way to make a passive in Norwegian is with bli:

• hviledagen blir beholdt

Both can mean the rest day is kept / will be kept, depending on context, but the -s passive often sounds a bit more compact and written.

The comma separates two short clause-like parts:

• Treningsplanen fungerer
• bare hviledagen beholdes

In very careful writing, many people would prefer a stronger break or a conjunction, for example:

• Treningsplanen fungerer; bare hviledagen beholdes.
• Treningsplanen fungerer, og bare hviledagen beholdes.
• Treningsplanen fungerer, men bare hviledagen beholdes.

So the original sentence is understandable, but it feels a bit compressed or terse.

It is understandable, but it sounds a little compact and somewhat written or edited rather than fully conversational.

A clearer or more natural-sounding version might be:

• Treningsplanen fungerer; bare hviledagen beholdes.
• Treningsplanen fungerer, men bare hviledagen beholdes.
• Det er bare hviledagen som beholdes.

If you wanted a more explicit active version, you could also say:

• Vi beholder bare hviledagen.

So the original is not wrong, but it is a bit tighter and less natural than some alternatives.

Yes, you could say:

• Treningsplanen fungerer, kun hviledagen beholdes.

But bare is more common and more everyday.
Kun often sounds a little more formal or written.

So for most normal speech and general writing, bare is the more natural choice.