Antrenamentul începe cu încălzirea.

Because -ul is the Romanian definite article attached to the end of a masculine/neuter singular noun.

• antrenament = training / workout
• antrenamentul = the training / the workout

Romanian usually puts the at the end of the noun instead of using a separate word like English does.

So:

• antrenament = a training session / training in general
• antrenamentul = the training session

Because the subject is antrenamentul, which is third person singular: the training.

The verb is a începe = to begin / to start.

Present tense:

• eu încep = I start
• tu începi = you start
• el/ea începe = he/she/it starts
• noi începem = we start
• voi începeți = you all start
• ei/ele încep = they start

Since antrenamentul is it, Romanian uses începe.

Cu usually means with.

In this sentence, începe cu... means starts with...

So:

• Antrenamentul începe cu încălzirea.
• The workout starts with the warm-up.

This is a very common structure in Romanian:

• Filmul începe cu o scenă dramatică. = The film starts with a dramatic scene.
• Lecția începe cu o întrebare. = The lesson starts with a question.

Încălzirea is a noun meaning the warm-up.

It comes from încălzire = warming up / warm-up, which is related to the verb a încălzi = to warm up / to heat.

So:

• încălzire = warm-up
• încălzirea = the warm-up

In fitness or sports contexts, încălzirea is the normal word for the warm-up part before exercise.

Romanian often uses the definite form when referring to a specific, expected activity or stage.

Here, încălzirea means the warm-up, as a known part of the workout routine. It sounds natural because the speaker is referring to that standard first phase of the training session.

Compare:

• cu încălzirea = with the warm-up
• cu o încălzire = with a warm-up

Both can be possible, but they are not exactly the same:

• cu încălzirea sounds like the usual, specific warm-up phase
• cu o încălzire means with a warm-up, more like one warm-up activity among others

Antrenament is a neuter noun in Romanian.

Romanian neuter nouns behave:

• like masculine in the singular
• like feminine in the plural

So in the singular you get:

• un antrenament
• antrenamentul

And in the plural:

• două antrenamente
• antrenamentele

This is why the singular definite article looks masculine: -ul.

A helpful approximate pronunciation is:

ahn-treh-nah-MEN-tool in-CHEH-peh koo een-kul-zi-REE-ah

A few key points:

• ce in începe sounds like che in check
• ă is a short central vowel, similar to the a in sofa
• î is a distinct Romanian sound, pronounced high and central; English does not have an exact equivalent
• z in încălzirea is pronounced like z in zoo

If you want to say it naturally, the stress is roughly:

• antrenaMENtul
• înCEpe
• încălziRIa

Not always. Romanian often uses the definite article where English may or may not use the, depending on context.

So antrenamentul could be translated as:

• the workout
• the training session
• sometimes just training, if that sounds more natural in English

For example:

• Antrenamentul începe la ora opt.
  • The workout starts at eight.
  • or Training starts at eight.

The Romanian definite form is still correct even if English chooses a more general-sounding translation.

Yes, Romanian word order is somewhat flexible, but Antrenamentul începe cu încălzirea is the most neutral and natural order.

This is the standard pattern:

• Subject + verb + prepositional phrase

You could change the order for emphasis, for example:

• Cu încălzirea începe antrenamentul.

But that sounds more marked or literary, and a learner should usually stick with:

• Antrenamentul începe cu încălzirea.

It can mean both.

• a începe = to begin / to start

In everyday English, starts is often the most natural translation here:

• The workout starts with the warm-up.

But begins with the warm-up is also correct.

Because Romanian usually uses an enclitic definite article, which means the article is attached to the end of the noun.

English:

• the training
• the warm-up

Romanian:

• antrenamentul
• încălzirea

This is one of the big differences between Romanian and English. Instead of putting the before the noun, Romanian usually adds it to the noun itself.

Yes. The noun încălzire can have different meanings depending on context:

• in sports: warm-up
• in general physical sense: warming
• in household/building contexts: heating

Examples:

• încălzirea înainte de alergare = the warm-up before running
• încălzirea apei = the heating of the water
• încălzirea centrală = central heating

In your sentence, because the context is antrenamentul, the meaning is clearly the warm-up.