Мне пора бы ложиться спать раньше, иначе утром не будет сил на тренировку.

Мне пора is a very common Russian way to say it’s time for me or I should be going / I ought to.

• мне is in the dative case
• пора is an impersonal word meaning it’s time

So Мне пора ложиться спать literally means something like To me, it is time to go to sleep.

This is different from Я должен..., which means I must / I am obligated to... and sounds more like duty or obligation.

Compare:

• Мне пора спать. = It’s time for me to sleep.
• Я должен спать. = I am supposed to sleep / I must sleep.

In this sentence, Мне пора sounds more natural and personal: the speaker feels that it’s time they started doing this.

Here бы softens the statement and adds a sense like:

• I really should...
• I ought to...
• It would be about time...

So:

• Мне пора ложиться спать раньше = It’s time for me to go to bed earlier.
• Мне пора бы ложиться спать раньше = I really should start going to bed earlier / I ought to be going to bed earlier.

This use of бы often suggests:

• hesitation,
• mild self-criticism,
• a thought the speaker has had for a while.

It sounds a bit less direct and a bit more reflective than plain Мне пора.

Ложиться спать is a set expression meaning to go to bed.

Literally:

• ложиться = to lie down / go to bed
• спать = to sleep

So together, ложиться спать means the action of getting into bed in order to sleep, not just the state of sleeping.

Compare:

• Мне пора спать. = It’s time for me to sleep.
• Мне пора ложиться спать. = It’s time for me to go to bed.

In many contexts, Russian prefers ложиться спать when talking about bedtime habits.

Good question. Russian uses aspect here to express different ideas.

• ложиться = imperfective
• лечь = perfective

In this sentence, the speaker is talking about a general habit or a repeated action: going to bed earlier as a routine. That is why ложиться is the natural choice.

• Мне пора бы ложиться спать раньше = I should start going to bed earlier (as a habit)

If you used лечь, it would sound more like a single completed action:

• Мне пора бы лечь спать пораньше сегодня. = I should go to bed earlier today.

So:

• ложиться = habitual / repeated / process
• лечь = one specific occasion

Раньше means earlier, and Russian often leaves the comparison implicit when it is obvious from context.

Here it means:

• earlier than I do now,
• earlier than usual,
• earlier than I’ve been going to bed.

So the sentence does not need to say exactly what it is being compared with.

This is very natural in Russian, just as in English:

• I should go to bed earlier.

You do not have to say earlier than now or earlier than usual unless you want to emphasize it.

Утром is the instrumental case, and Russian often uses the instrumental without a preposition to express time when something happens.

So:

• утром = in the morning
• вечером = in the evening
• днём = during the day
• ночью = at night

This is just a standard time expression pattern.

Examples:

• Я работаю утром. = I work in the morning.
• Мы увидимся вечером. = We’ll see each other in the evening.

So иначе утром не будет сил... means otherwise, in the morning, there won’t be any energy/strength...

Because this is an existential construction: it means there will not be any strength/energy.

In Russian, when быть is negated in this kind of meaning, the thing that does not exist is often put in the genitive:

• будет сила = there will be strength
• не будет сил = there will be no strength / there won’t be any energy

This is a very common pattern:

• У меня будет время. = I will have time.
• У меня не будет времени. = I won’t have time.
• Будут деньги. = There will be money.
• Не будет денег. = There won’t be any money.

So сил is genitive, not nominative.

The noun сила literally means strength, but in many everyday contexts Russian uses the plural силы to mean:

• strength,
• energy,
• resources,
• stamina.

After negated не будет, it becomes сил (genitive plural).

So:

• есть силы = there is strength / I have the energy
• нет сил = there is no strength / I have no energy
• не будет сил = there won’t be any energy

This is extremely common Russian usage. In English we often use singular strength or energy, but Russian often prefers the plural idea here.

Here на тренировку means for training / for the workout.

The pattern is:

• сил на что? = strength for what?
• времени на что? = time for what?
• денег на что? = money for what?

So на + accusative often shows the purpose or target of the resource.

Examples:

• У меня нет времени на домашнее задание. = I don’t have time for homework.
• Не хватает денег на билет. = There isn’t enough money for a ticket.
• Не будет сил на тренировку. = There won’t be enough energy for training / for the workout.

It does not mean motion to the training session here, even though на can also mean movement onto/to something in other contexts.

Иначе means otherwise.

It introduces the negative consequence if the speaker does not follow the first idea.

So the structure is:

• Мне пора бы ложиться спать раньше = I really should go to bed earlier
• иначе... = otherwise...
• утром не будет сил на тренировку = in the morning there won’t be energy for training

This is very similar to English:

• I should go to bed earlier, otherwise I won’t have energy for training in the morning.

Russian often leaves out pronouns when they are understood from context.

In утром не будет сил на тренировку, the idea is really:

• (у меня) утром не будет сил на тренировку

That means:

• I won’t have energy for training in the morning
• literally: there won’t be strength for me in the morning for training

Russian very often omits у меня if it is obvious whose strength or energy is being discussed. Since the first half already talks about the speaker, the second half naturally continues that idea.

Yes, that is also possible.

Russian word order is flexible, and different placements can change the emphasis slightly.

Compare:

• Мне пора бы ложиться спать раньше.
• Мне пора бы раньше ложиться спать.

Both mean basically the same thing: I should be going to bed earlier.

A rough nuance:

• ложиться спать раньше emphasizes the whole action go to bed earlier
• раньше ложиться спать puts a bit more focus on earlier

In ordinary speech, both are natural.

It sounds natural and idiomatic.

The only part that adds a slightly reflective tone is пора бы, which sounds like someone thinking to themselves:

• I really should...
• I ought to...

That is very normal in conversation.

The whole sentence sounds like something a person might say after noticing they are too tired in the mornings:

• Мне пора бы ложиться спать раньше, иначе утром не будет сил на тренировку.

So yes, it is good, natural Russian.