Poranny spacer pomaga mi odzyskać energię.

Because spacer is a masculine noun in Polish, and the adjective has to agree with it in gender, number, and case.

• spacer = masculine singular
• so the adjective takes the masculine singular form: poranny

Compare:

• poranny spacer = a morning walk
• poranna kawa = morning coffee
• poranne światło = morning light

So poranny matches spacer.

Poranny means morning or of the morning. It is an adjective formed from poranek/rano-related meaning.

In this sentence, poranny spacer means a morning walk.

A useful distinction:

• rano = in the morning (an adverb)
• poranny = morning as an adjective

So:

• Spacer rano = a walk in the morning
• Poranny spacer = a morning walk

Mi means to me. It is the dative form of ja (I).

So:

• pomaga mi = helps me
• literally: is helpful to me

Polish often uses the dative with verbs like pomagać.

You may also see:

• mnie = me
• mi = to me / me

In this kind of sentence, mi is the normal unstressed form and sounds the most natural:

• Poranny spacer pomaga mi...

Using mnie would usually add emphasis:

• Poranny spacer pomaga mnie odzyskać energię is not correct here.
• The correct emphatic version would be something like Poranny spacer pomaga właśnie mnie odzyskać energię, but that is marked and less neutral.

Because the subject is poranny spacer, which is third person singular.

The verb pomagać is conjugated here as:

• (on/ona/ono) pomaga = he/she/it helps

Since spacer is singular, the verb must also be singular:

• Poranny spacer pomaga... = A morning walk helps...

Compare:

• Poranne spacery pomagają... = Morning walks help...
• Pomagam... = I help...
• Pomagasz... = You help...

Because Polish often uses pomagać + infinitive to mean help someone do something.

So:

• pomaga mi odzyskać energię = helps me regain energy

This structure is very common:

• Pomaga mi zasnąć = It helps me fall asleep
• To pomaga mi pracować = This helps me work
• Ćwiczenia pomagają nam lepiej się czuć = Exercise helps us feel better

So the infinitive tells you what the walk helps the speaker do.

Odzyskać is the perfective infinitive, while odzyskiwać is imperfective.

Here, odzyskać energię suggests reaching a result: to get the energy back / to regain energy.

That fits well with the idea of recovering something successfully. In many pomagać + infinitive sentences, Polish often prefers the form that focuses on the intended result.

Very roughly:

• odzyskać = regain, recover fully/resultatively
• odzyskiwać = be regaining, regain repeatedly/in process

In this sentence, odzyskać sounds natural because the point is the effect:

• the walk helps me get my energy back

Because energia is the direct object of odzyskać, so it takes the accusative case.

• nominative: energia
• accusative: energię

So:

• odzyskać energię = regain energy

This is a very common pattern:

• mieć energię = to have energy
• tracić energię = to lose energy
• odzyskać energię = to regain energy

For many feminine nouns ending in -a, the accusative singular changes to -ę:

• kawa → kawę
• muzyka → muzykę
• energia → energię

Not in this sentence.

Energii is a different case form of energia. It can be:

• genitive singular
• locative singular
• nominative/genitive plural, depending on context

But after odzyskać, you need the accusative direct object, so the correct form is energię.

Correct:

• odzyskać energię

Not correct here:

• odzyskać energii

Yes, Polish word order is fairly flexible, but the neutral order here is very natural:

• Poranny spacer pomaga mi odzyskać energię.

You could change the order for emphasis, for example:

• Mi poranny spacer pomaga odzyskać energię.
• Energię pomaga mi odzyskać poranny spacer.

These are grammatical, but they sound more marked or stylistically special. For a learner, the original version is the best neutral model.

Yes. That is very natural too.

• odzyskać energię = regain energy
• odzyskać siły = regain strength / recover one’s strength

Both work, but they feel slightly different:

• energia can sound more like energy, vigor, mental/physical drive
• siły often suggests strength or recovering after tiredness, illness, or effort

So both are good Polish, just with a slightly different nuance.