После тренировки я хочу принять душ.

Because после requires the genitive case.

The base form is тренировка.
In the genitive singular, it becomes тренировки.

So:

• тренировка = workout, training session
• после тренировки = after the workout / after training

This is a very common pattern in Russian:

• после работы = after work
• после урока = after the lesson
• после фильма = after the movie

It is genitive singular.

The noun тренировка is a feminine noun ending in -а.
For many feminine nouns of this type, the genitive singular changes -а to -и:

• тренировка → тренировки
• книга → книги
• машина → машины

So in после тренировки, the word is singular and genitive.

This is a very normal Russian structure.

хотеть means to want, and after it Russian usually uses an infinitive to say what someone wants to do:

• я хочу спать = I want to sleep
• я хочу есть = I want to eat
• я хочу принять душ = I want to take a shower

So:

• хочу = I want
• принять = to take

Together: I want to take...

This is about aspect.

• принимать = imperfective
• принять = perfective

In this sentence, принять душ suggests a single, complete action: taking one shower. That is why the perfective verb принять is natural here.

Compare:

• Я хочу принять душ. = I want to take a shower.
  (one complete shower)

• Я люблю принимать душ по утрам. = I like taking showers in the morning.
  (habit / repeated action)

After хочу, both aspects are sometimes possible, but the choice changes the feel:

• хочу принять душ = I want to go take a shower now / as one completed action
• хочу принимать душ чаще = I want to take showers more often
  (habit or ongoing/repeated action)

This is just an idiomatic expression.

In Russian, принять душ means to take a shower.
You should learn it as a set phrase, not translate each word literally.

Some similar expressions in Russian also use verbs differently from English:

• принять ванну = take a bath
• принимать лекарство = take medicine

So even though принять can mean accept in other contexts, in принять душ it means take in the sense of have a shower.

It is in the accusative case, because it is the direct object of принять.

However, for a masculine inanimate noun like душ, the accusative looks the same as the nominative:

• nominative: душ
• accusative: душ

So the form does not change, but grammatically it is still accusative.

Yes, absolutely.

Russian often leaves out subject pronouns when they are clear from the verb form.

• Я хочу принять душ.
• Хочу принять душ.

Both mean I want to take a shower.

Including я can add a little emphasis or simply make the sentence feel more explicit, but it is not required.

Yes. Russian word order is flexible, although some orders sound more neutral than others.

The most neutral version here is:

• После тренировки я хочу принять душ.

You could also say:

• Я хочу принять душ после тренировки.

This puts the focus a bit more on wanting to take a shower, and then adds after training afterward.

Both are correct. Russian word order often depends on emphasis, rhythm, and context.

Often yes, but it usually refers to a workout, practice session, or training session.

Depending on context, После тренировки could mean:

• after the workout
• after practice
• after training

For example:

• after a gym session
• after sports practice
• after physical training

So the exact English translation depends on the situation.

Yes. There are several natural alternatives, but they are not always identical in tone.

Some common ones are:

• принять душ = to take a shower
  Very standard and common.

• помыться = to wash oneself
  Broader meaning; may or may not specifically mean showering.

• сходить в душ = to go take a shower / go to the shower
  Often used when emphasizing going somewhere to shower.

Examples:

• После тренировки я хочу принять душ.
  Standard: I want to take a shower.

• После тренировки я хочу помыться.
  I want to wash up.

• После тренировки я хочу сходить в душ.
  I want to go take a shower.

So принять душ is a very good basic phrase to learn.

Because Russian has no articles.

English says:

• after the workout
• take a shower

Russian simply says:

• после тренировки
• принять душ

Russian relies on context to show whether something is a, the, or just a general idea.

So the sentence can naturally mean:

• After the workout, I want to take a shower.
• After training, I want to take a shower.

The exact interpretation depends on context.

In this sentence, после means after in a time sequence.

It is used with the genitive to mean after something:

• после обеда = after lunch
• после школы = after school
• после тренировки = after training

So here it is strictly temporal: one event happens after another.

You could say:

• После тренировок я хочу принимать душ.

Why these changes?

• тренировок is genitive plural after после, because now you mean workouts in general.
• принимать is imperfective, because it can suggest a habitual or repeated action.

So:

• После тренировки я хочу принять душ.
  After this workout, I want to take a shower.

• После тренировок я хочу принимать душ.
  After workouts, I want to take showers / I want to shower after workouts.