Learn Hardcore Spanish (Latin America): Si mantengo esta disciplina y este optimismo, en unos meses habré cambiado mi rutina de manera profundamente equilibrada. - If I keep this discipline and this optimism, in a few months I will have changed my routine in a deeply balanced way.

Si mantenga – incorrect here; subjunctive doesn’t follow si in this kind of clause.
Si mantuviera esta disciplina, habría cambiado mi rutina…
→ This is a hypothetical/unreal conditional: If I were to keep this discipline, I would have changed… (but I probably won’t).

So the original sentence talks about a realistic plan, so mantengo (present indicative) is correct.

Can I say Si mantendré esta disciplina instead of Si mantengo?

No. In standard Spanish, you do not use the future tense directly after si in conditional sentences like this.

Correct:

Si mantengo esta disciplina, en unos meses habré cambiado…

Incorrect:

Si mantendré esta disciplina, en unos meses habré cambiado… ✗

General rule:

After si (meaning if), use present, imperfect subjunctive, or pluperfect subjunctive, but not the simple future.

So: Si + present, future → not Si + future.

Why is the subject yo omitted? Could I say Si yo mantengo esta disciplina?

Spanish usually omits subject pronouns because the verb ending already tells you who the subject is.

mantengo already shows 1st person singular (yo).

So:

Si mantengo esta disciplina… = perfectly natural and typical.
Si yo mantengo esta disciplina… = grammatically correct, but sounds more emphatic, like:
- If *I (as opposed to someone else) keep this discipline…*

Use yo when you want to contrast or emphasize the subject; otherwise, dropping it is more natural.

Why is it esta disciplina instead of la disciplina?

Both are possible, but they don’t feel exactly the same.

esta disciplina = this discipline (of mine / right now)
It sounds more personal and specific: the particular discipline you’re currently practicing or referring to.
la disciplina = the discipline in a more general or previously defined sense.
It can sound more abstract or less immediately “close” to the speaker.

In context, esta disciplina suggests:

If I keep *this current level of discipline I have now…*

It underlines that the discipline is part of your current situation.

What exactly does unos meses mean? Is it “some months”, “a few months”, or “about X months”?

Unos meses can be translated as:

a few months
several months
some months
about a few months from now

It’s approximate, not exact. It often implies:

More than 2, but not very many.
You’re not being precise about the number.

Nuance compared to similar words:

pocos meses – few months with a slight idea of “not many”.
algunos meses – also some months, sometimes slightly more neutral or “some specific ones”.
unos meses – casual, approximate: in a few months / after some months.

In this sentence: en unos meses ≈ in a few months.

Why is it en unos meses and not dentro de unos meses? Are they different?

Both are correct, and often interchangeable, but with slight nuance:

en unos meses
Very common and natural. Means in a few months (from now). It’s often used with future meaning when combined with a future tense.
dentro de unos meses
Also in a few months, but it can emphasize the idea of “within a span of time until that point”. It can sound slightly more explicit or formal in some contexts.

In this sentence:

En unos meses habré cambiado mi rutina…
Dentro de unos meses habré cambiado mi rutina…

Both are fine. En unos meses is shorter and very typical in speech.

Why use habré cambiado (future perfect) instead of just cambiaré (simple future)?

The future perfect (habré cambiado) expresses that the change will already be completed by a certain future time.

En unos meses habré cambiado mi rutina…
→ In a few months, I *will have changed my routine…*
Focus: looking back from that future point at a completed change.

If you said:

En unos meses cambiaré mi rutina…
→ In a few months I’ll change my routine…
Focus: the action will happen then, but not necessarily emphasizing it as something already accomplished by that point.

In English, the original clearly corresponds to:

I will have changed my routine in a deeply balanced way.

So the Spanish habré cambiado is the natural match.

Why is it de manera profundamente equilibrada and not just profundamente equilibrada?

De manera + adjective is a common way in Spanish to turn an adjective into an adverbial phrase (how something is done):

de manera equilibrada = in a balanced way
de manera rápida = quickly / in a quick way
de manera honesta = honestly / in an honest way

In the sentence:

mi rutina de manera profundamente equilibrada
→ my routine in a deeply balanced way (i.e., the manner in which your routine will be changed).

You could say:

habré cambiado mi rutina profundamente y de forma equilibrada
habré cambiado mi rutina de forma profundamente equilibrada

But if you remove de manera, you get:

habré cambiado mi rutina profundamente equilibrada
This sounds like you are describing the routine itself as “deeply balanced” (more like an adjective phrase attached to rutina) rather than the manner of changing it. That can sound confusing or off.

So de manera clearly marks that equilibrada is modifying the way you change, not just describing the routine as a static quality.

Why is it equilibrada and not equilibrado or equilibradamente?

Equilibrada agrees in gender and number with manera, which is feminine singular:

manera equilibrada
feminine (manera) + feminine adjective (equilibrada)

Structure:

de manera + adjective
functions like an adverb: in a … way

Alternatives and their nuances:

equilibrado
- Would agree with a masculine noun, but manera is feminine, so equilibrado would be grammatically wrong here.
equilibradamente
- This is the pure adverb form: in a balanced way.
- You could say:
  - …habré cambiado mi rutina profundamente y equilibradamente.
  - …habré cambiado mi rutina de manera equilibrada y profunda.
- Perfectly correct, but de manera equilibrada sounds more natural and common in everyday speech than equilibradamente, which can feel more formal or bookish.

So de manera profundamente equilibrada is both grammatically correct and stylistically natural.

Is the word order fixed? Could I say En unos meses mi rutina habrá cambiado de manera profundamente equilibrada?

The word order is flexible in Spanish. You can move parts around to change emphasis or style.

Original:

En unos meses habré cambiado mi rutina de manera profundamente equilibrada.
Focus on I as the agent (yo habré cambiado).

Alternative:

En unos meses mi rutina habrá cambiado de manera profundamente equilibrada.
Now the focus shifts slightly to mi rutina as the subject that will have changed.

Both are grammatically correct. Subtle differences:

habré cambiado mi rutina → emphasizes your action of changing it.
mi rutina habrá cambiado → emphasizes the state of your routine as something that will be different.

In many contexts they are nearly interchangeable; it’s more about style and focus.

Is this sentence specifically “Latin American” Spanish? Would it be different in Spain?

This sentence is perfectly natural in both Latin American and Peninsular (Spain) Spanish. There is nothing strongly regional about:

Si mantengo esta disciplina y este optimismo…
en unos meses habré cambiado mi rutina…
de manera profundamente equilibrada.

Points where regional variation could appear (but doesn’t here):

Pronouns like vos (in some Latin American countries) instead of tú – not used in this sentence.
Vocabulary differences (e.g. ordenador vs computadora) – not relevant here.
Some preference for forma vs manera in certain places – but both are understood everywhere.

So you can safely use this sentence throughout the Spanish-speaking world.