Во время бега мне помогает музыка: с ней легче держать ритм.

Во is just a variant of в used to make pronunciation easier before certain consonant clusters. Since время begins with вр-, Russian prefers во время.

So:

• в школе = in school
• во Франции = in France
• во время = during

Here во время is a fixed expression meaning during.

Because во время requires the genitive.

So:

• во время урока = during the lesson
• во время дождя = during the rain
• во время бега = during running / while running

The dictionary form is бег, but after во время it becomes бега.

Literally it means during running.

In natural English, you would usually say:

• while running
• when I run
• during a run

Russian often uses this noun-based structure where English might prefer a clause.

The verb помогать uses the person receiving help in the dative case.

So Russian says, literally:

• Музыка помогает мне = Music helps me

or with a different word order:

• Мне помогает музыка

Here:

• мне = to me
• музыка = music
• помогает = helps

This is very normal with помогать.

Both are correct. Russian word order is flexible.

• Музыка помогает мне sounds more neutral if you are simply stating the fact.
• Мне помогает музыка puts a little more focus on me or on the experience from the speaker’s point of view.

In this sentence, the order flows naturally from Во время бега... and makes it sound like As for me, during running, music helps.

Russian present tense is often used for a general truth, habit, or repeated situation.

So мне помогает музыка means something like:

• music helps me
• music is helpful to me
• music helps me when I run

It does not have to mean only right now at this exact moment.

The colon introduces an explanation or clarification of the first idea.

So the structure is:

• Music helps me during running: here is how / why:
• with it, it’s easier to keep rhythm

The second part explains the first part.

A dash could also sometimes work in Russian, but the colon is very natural here because the second clause gives the reason or explanation.

Because с meaning with requires the instrumental case.

The noun музыка is feminine, so the pronoun referring to it is:

• nominative: она = she / it
• instrumental after с: с ней = with her / with it

Since музыка is grammatically feminine, Russian uses the feminine pronoun form.

After many prepositions, Russian third-person pronouns gain an initial н-.

So:

• её → у неё
• ей → к ней
• ей → с ней

This is a standard rule with personal pronouns after prepositions.

Because музыка is a feminine noun grammatically.

In Russian, pronouns agree with the grammatical gender of the noun:

• музыка → feminine → она, ней
• ритм → masculine → он, ним

This grammatical gender does not mean music is literally female; it is just how the noun behaves in the language.

Легче is the comparative form meaning easier.

It comes from лёгкий / легко:

• легко = easily / easy
• легче = more easily / easier

In this sentence, легче works in an impersonal construction:

• с ней легче держать ритм = with it, it is easier to keep the rhythm

Russian often uses this kind of structure without an explicit it is.

It is understood from the first clause.

The full idea is basically:

• С ней мне легче держать ритм

But Russian often omits words that are already clear from context.

So the second half means:

• with it, it’s easier for me to keep rhythm

Leaving out мне makes the sentence smoother and avoids repetition.

After words like легко, трудно, можно, нельзя, лучше, легче, Russian often uses an infinitive to say what action is easy, hard, possible, better, and so on.

Examples:

• Легко понять = It is easy to understand
• Трудно объяснить = It is hard to explain
• С ней легче держать ритм = With it, it is easier to keep rhythm

So держать means to keep / to maintain.

Literally, it means to keep the rhythm.

In context, it means something like:

• maintain a steady rhythm
• keep a consistent beat
• stay in pace

When talking about running, this can mean matching your steps or movement to a regular beat.

Yes, depending on context, the natural English translation might be rhythm or pace.

Literally, ритм is rhythm. But in running, keeping a rhythm often overlaps with keeping a steady pace or cadence.

So in English, a translator might choose:

• keep the rhythm
• keep a rhythm
• maintain my pace

The Russian word itself is still ритм.

By default, it sounds like a general statement about the speaker’s usual experience.

So it means something like:

• When I run, music helps me
• During a run, music helps me

If Russian wanted to make it clearly about one specific run, the context would usually make that obvious.

Yes. Both are possible, but they feel slightly different.

• Во время бега = during running; a bit more general or activity-focused
• Во время пробежки = during a run / during my jog; a bit more concrete

So:

• Во время пробежки мне помогает музыка is also natural.

In standard Russian writing, ё is often written as е unless it is needed to avoid confusion.

So легче is usually pronounced лёгче, even though it is commonly written легче.

This is very common in Russian spelling. Native speakers usually know the correct pronunciation from familiarity.

Yes, several versions are possible, with slightly different emphasis:

• Во время бега музыка помогает мне: с ней легче держать ритм.
• Музыка помогает мне во время бега: с ней легче держать ритм.
• С музыкой во время бега легче держать ритм.

All are grammatical, but the original sentence sounds very natural and well-balanced. It first introduces the situation, then the main point, then the explanation.