Learn Hardcore German: Eine gute Haltung macht es mir beim Bergsteigen leichter, ruhig weiterzugehen. - Good posture makes it easier for me to keep walking calmly while mountaineering.

machen (to make) needs a subject in the nominative: Wer oder was macht etwas? (Who or what makes something?)
The thing that is actively "making something easier" is eine gute Haltung.
Therefore Haltung is in the nominative, and since Haltung is feminine, you get eine gute Haltung (feminine, nominative, singular).

So the basic skeleton is:

Eine gute Haltung (subject, nominative)
macht (verb)
es (object)
mir (indirect object, dative)
leichter, ... (complement: "easier (for me), to …").

What does the es in macht es mir leichter do, and could it be left out?

The es here is a dummy/placeholder object.

Structure: etwas (Subjekt) macht es jemandem leichter, etwas zu tun
- Eine gute Haltung = subject
- es = dummy Akkusativobjekt (accusative object)
- mir = dative object ("for me")
- leichter, ruhig weiterzugehen = what becomes easier

In German, this pattern etwas macht es jemandem leicht/leichter, ... zu ... is idiomatic. The es does not refer to anything concrete; it just fills the slot of a direct object that goes with machen in this expression.

You normally cannot just drop es here.

✗ Eine gute Haltung macht mir leichter, ruhig weiterzugehen. – ungrammatical.
✓ Eine gute Haltung macht es mir leichter, ruhig weiterzugehen. – correct.

You could rephrase the sentence without es by changing the structure, e.g.:

Eine gute Haltung macht mir das Bergsteigen leichter.
Here das Bergsteigen is now the concrete accusative object instead of es.

Why is it mir (dative) and not mich (accusative)?

mir is dative because it answers the question für wen? / wem? (for whom?), not wen? / wen? (whom as a direct object).

The pattern is:

etwas macht es jemandem leichter/schwerer, etwas zu tun
- jemandem = dative (the person affected; "for someone")

So in this sentence:

mir = "for me" → wem macht eine gute Haltung es leichter? – mir.

If you used mich (accusative), it would sound like I myself am the direct object of machen, which is not what is meant here.

What exactly does beim Bergsteigen mean, and what is the role of beim?

beim is a contraction of bei dem.

bei = "at", "while", "during", "in the context of"
dem = dative singular article (here for das Bergsteigen, neuter)

Bergsteigen is a noun formed from the verb bergsteigen ("to climb mountains"). As a noun, it’s das Bergsteigen (neuter).

So:

bei dem Bergsteigen → contracted to beim Bergsteigen

Meaning in context: "while mountain climbing / when I’m climbing in the mountains / during mountain climbing".

Function in the sentence: it is an adverbial phrase of situation/time: wann / wobei wird es mir leichter? – beim Bergsteigen.

Why is it leichter and not just leicht? What is this form doing?

leichter is the comparative form of leicht ("easy").

leicht = easy
leichter = easier

The construction jemandem etwas leichter machen = "to make something easier for someone".

So the phrase macht es mir leichter literally means:

"makes it easier for me (to ...)"

If you just said macht es mir leicht, it would be grammatically possible, but the idiom es jemandem leichter machen is much more common and natural, especially when followed by a zu-infinitive (..., etwas zu tun).

How does the part ruhig weiterzugehen work grammatically, and what is the role of zu?

ruhig weiterzugehen is a zu-infinitive clause depending on leichter (machen).

Pattern:

jemandem es leichter machen, etwas zu tun

Here:

ruhig = adverb modifying weitergehen ("calmly", "without stress", "steadily")
weiterzugehen = weitergehen ("to keep going, to continue walking") in the zu-infinitive form

In German, when you have an infinitive with zu and a separable verb like weitergehen, zu goes between the prefix and the verb stem:

weitergehen → weiterzugehen
(similarly: aufstehen → aufzustehen, mitkommen → mitzunehmen, etc.)

So ruhig weiterzugehen = "to continue (going/walking) calmly".

Grammatically, this whole unit explains what is made easier:

Eine gute Haltung macht es mir leichter, ruhig weiterzugehen.
→ A good posture makes it easier (for me) to keep going calmly.

What exactly does ruhig mean here – "quietly" or "calmly"?

In this context, ruhig is an adverb and means "calmly / steadily / without tension or stress", not "quietly" in the sense of "not making noise".

With body actions like walking, breathing, continuing an activity, ruhig usually means "calm, relaxed, not hectic".
So ruhig weitergehen suggests continuing at a calm pace, not panicking, not rushing.

So it’s modifying the manner of weitergehen ("how do I continue? calmly"), not describing the physical loudness.

What is weiterzugehen formed from, and why is zu inside the verb?

weiterzugehen comes from the separable verb weitergehen.

weiter = particle/prefix meaning "further, on, continuing"
gehen = "to go"

In normal finite forms, the prefix separates:

Ich gehe weiter. – I continue (walking/going).

In infinitive forms with zu, zu is placed between the prefix and the verb stem:

weitergehen → weiterzugehen
General pattern:
- anfangen → anzufangen
- aufstehen → aufzustehen
- mitkommen → mitzukommen

So weiterzugehen is the correct zu-infinitive form of weitergehen.

Could the sentence be rephrased without the es? For example, using das Bergsteigen as the object?

Yes, you can rephrase to avoid the dummy es by making the activity itself the direct object. For example:

Eine gute Haltung macht mir das Bergsteigen leichter.
- das Bergsteigen = accusative object, the thing that becomes easier
- mir = dative ("for me")

If you want to keep the idea of continuing calmly, you might say:

Eine gute Haltung macht mir das Bergsteigen leichter, sodass ich ruhig weitergehen kann.
("... so that I can continue calmly.")

But once you use the specific object das Bergsteigen, the structure with es is no longer necessary and would be wrong:

✗ Eine gute Haltung macht es mir das Bergsteigen leichter. – incorrect.

Why is there a comma before ruhig weiterzugehen?

German normally puts a comma before a zu-infinitive clause when it is expanded, i.e. has additional elements like objects or adverbs.

Here, we have:

ruhig weiterzugehen – the infinitive weiterzugehen with the adverb ruhig → expanded infinitive clause.

Rule (simplified):

Use a comma before zu + infinitive when the infinitive phrase is longer or has its own complements/adverbs, or when it depends on certain verbs/adjectives like leicht, schwer, gut, schön, etc.

So:

macht es mir leichter, ruhig weiterzugehen. – comma is required and correct.

What does Haltung mean here exactly – "posture" or "attitude", and what gender is it?

Haltung is a feminine noun: die Haltung.

It has two common meanings:

physical posture, body position (how you hold your back, shoulders, etc.)
attitude, stance (towards a topic or situation)

In the context of beim Bergsteigen, eine gute Haltung most naturally means good physical posture (e.g., straight back, balanced stance while climbing).

Because Haltung is feminine, you get:

eine gute Haltung (nominative feminine singular)

What is the grammatical status and gender of Bergsteigen?

Bergsteigen in this sentence is a noun derived from a verb (Substantivierung).

The verb is bergsteigen = "to climb mountains"
As a noun, it becomes das Bergsteigen (neuter)

Evidence:

It stands after beim (= bei dem) → dative singular, neuter article dem
No article is written because activity nouns formed from verbs are often used without an article in such constructions, but you can see the gender from bei dem → beim.

So grammatically:

beim Bergsteigen = bei dem Bergsteigen
Bergsteigen = neuter noun, here in the dative case after bei.