Continuei o treino a ponto de me machucar.

Continuei is the 1st person singular of continuar in the pretérito perfeito (simple past / preterite).

So it means I continued in a completed past event.

Compare:

• continuei = I continued
• continuava = I was continuing / I used to continue

In this sentence, continuei presents the action as a finished event in the past.

Portuguese often omits subject pronouns when the verb ending already makes the subject clear.

Here, continuei already tells you the subject is I.

So both are possible:

• Continuei o treino...
• Eu continuei o treino...

The version without eu is very normal and natural. Adding eu usually gives extra emphasis, contrast, or clarity.

Treino usually means:

• training
• practice
• workout
• training session

In this sentence, o treino most naturally means the workout or the training session.

In Brazilian Portuguese, treino is very common in everyday speech, especially for sports and exercise.

The article o is there because the speaker is referring to a specific workout/training session.

So:

• o treino = the workout / the training session

Without the article, Continuei treino would sound unnatural in standard Portuguese.

Portuguese uses definite articles more often than English in many contexts, and here o treino is the normal form.

Both are possible, but they focus on slightly different things:

• Continuei o treino = I continued the workout
  • focus on the training session as a whole
• Continuei treinando = I kept training
  • focus on the ongoing action

They are very close in meaning here. The original sentence sounds natural and emphasizes the workout/session itself.

A ponto de is a very common expression meaning:

• to the point of
• to such an extent that
• enough to

So:

• a ponto de me machucar = to the point of hurting myself

It introduces a consequence or extreme degree.

Other examples:

• Ele gritou a ponto de perder a voz.
  He shouted to the point of losing his voice.

• Estava cansado a ponto de dormir em pé.
  He was tired enough to fall asleep standing up.

For learners, the best thing is to treat a ponto de as the standard fixed expression.

So you should learn:

• a ponto de + infinitive
• a ponto de + noun

Example:

• a ponto de chorar
• a ponto de exaustão

You may sometimes come across ao ponto de, but a ponto de is the form you should actively use.

Because the expression is a ponto de.

The structure is:

• a ponto de + infinitive
• a ponto de + noun

So:

• a ponto de me machucar
• a ponto de desmaiar
• a ponto de exaustão

The de is required by the expression.

In Brazilian Portuguese, putting the pronoun before the infinitive is very common and natural:

• de me machucar
• para me ajudar
• sem me avisar

So me machucar is the normal Brazilian way.

Machucar-me is grammatically possible, but it sounds:

• more formal
• more literary
• less conversational
• sometimes more European Portuguese in flavor

For everyday Brazilian Portuguese, me machucar is the best choice.

Yes. Me refers back to the speaker, so the idea is hurt myself.

Breakdown:

• machucar = to hurt / to injure
• me machucar = to hurt myself / to get hurt

So the speaker continued the workout until they caused injury or pain to themselves.

Machucar can cover a range from hurt to injure.

Depending on context, it can mean:

• a small physical hurt
• a more serious injury
• sometimes emotional hurt in other contexts

In this sentence, because of the workout context, it most likely means physically hurt/injured myself from overdoing it.

So the exact strength depends on context, but here it suggests more than just mild discomfort.

Yes, and it would be natural:

• Continuei o treino até me machucar.

But the nuance is a little different:

• a ponto de me machucar = emphasizes the degree/intensity
  • to the point of hurting myself
• até me machucar = emphasizes the endpoint
  • until I hurt myself

Both are possible, but a ponto de sounds a little more focused on how far the action went.

Yes, it is natural.

Some other natural ways to express a similar idea are:

• Continuei treinando a ponto de me machucar.
• Continuei o treino até me machucar.
• Treinei tanto que me machuquei.

The original sentence is perfectly fine and sounds normal in Brazilian Portuguese.

Yes. Treino is flexible.

It can refer to:

• a gym workout
• sports practice
• athletic training
• a training session in general

So without more context, o treino could be:

• a gym session
• football practice
• running training
• another kind of physical training

The sentence itself does not limit it to only one type.