Treningen er fysisk.

Because Norwegian often marks the by adding it to the end of the noun.

• trening = training, exercise, a workout
• treningen = the training, the exercise, the workout

The ending -en is the definite singular ending for many masculine/common-gender nouns in Bokmål.

Er is the present tense of å være, which means to be.

So grammatically, this sentence follows a very common pattern:

subject + verb + adjective

• Treningen = the training
• er = is
• fysisk = physical

Here, fysisk is a predicate adjective, not an adjective placed directly before a noun.

Compare:

• fysisk trening = physical training
• treningen er fysisk = the training is physical

In the first example, the adjective comes before the noun. In the second, it comes after er because it is describing the subject through the verb to be.

In this sentence, fysisk is the correct form.

There are two useful things to know:

1. Treningen is singular.
2. Many adjectives ending in -sk do not add -t in the neuter form.

So fysisk often stays fysisk.

Also, because this is a predicate adjective after er, you are not using the definite/plural form fysiske here.

For example:

• en fysisk aktivitet = a physical activity
• et fysisk krav = a physical requirement
• aktivitetene er fysiske = the activities are physical

Usually yes, but the exact nuance depends on context.

In Norwegian, fysisk can mean:

• related to the body
• involving bodily effort
• not just mental or theoretical

So this sentence could suggest that the training involves bodily activity or is physically demanding, depending on the situation.

Yes. Trening is a flexible word in Norwegian.

Depending on context, it can mean:

• training in general
• exercise
• a workout
• a practice session

So treningen could mean:

• the training
• the exercise
• the workout
• the practice

The surrounding context tells you which English translation fits best.

Yes. That would sound more general.

• Treningen er fysisk = talking about a specific training session or specific training already known in the conversation
• Trening er fysisk = talking about training in general

So the definite form treningen makes it more specific.

A rough guide for an English speaker is:

TREH-ning-en ehr FY-sisk

A few notes:

• treningen has stress near the beginning: TREH-ningen
• er is usually short and light
• fysisk starts with fy-, where y is not exactly like English ee or oo. It is a rounded vowel that English does not really have.

If you cannot produce the Norwegian y yet, an approximate version is fine at first, but it is worth practicing because y is very common in Norwegian.

Yes, it is grammatical and natural, especially when contrasting one kind of training with another.

For example, it could make sense in contexts like these:

• one kind of training is physical, another is mental
• someone is explaining that the training involves bodily effort
• someone is distinguishing physical training from theoretical instruction

So the sentence is simple, but it works best when there is some context around it.