pǎobù yǐqián xiān rèshēn.

In Chinese, 以前 often comes after a word or phrase to mean before that time / before doing that.

So:

跑步以前 = before running

This is different from English word order. English says before running, but Chinese says running + before.

You can think of it as:

• 跑步 = running
• 以前 = before that time

So the whole phrase means before running.

It is functioning as an action phrase here: to run / running.

In Chinese, verbs and verb phrases can often be used directly before time words like 以前, 以后, 的时候, and so on.

So 跑步以前 is very natural and means before running.

先 means first or do this first.

In this sentence, it shows that warming up happens before the main action:

• 先热身 = warm up first

There is an implied next step: then run.

So even though Chinese does not explicitly say then run, the idea is:

• Before running, first warm up.

Chinese often leaves the second step understood if it is obvious from context.

A fuller version could be:

跑步以前，先热身，再跑。
Before running, warm up first, then run.

But because 跑步 has already been mentioned, 再跑 is easy to infer, so it can be omitted.

That makes 跑步以前先热身。 sound natural and concise.

Yes, 热身 can be used as a verb meaning to warm up.

So:

• 热身 = to warm up
• 先热身 = warm up first

Chinese often uses the same form where English might use either a noun or a verb depending on context.

For example:

• 比赛前先热身。 = Warm up before the match.

So in your sentence, 热身 is clearly verbal.

Yes. That is very natural.

These are all possible:

• 跑步以前先热身。
• 跑步之前先热身。
• 跑步前先热身。

All of them mean roughly Warm up before running.

A quick comparison:

• 前: shortest and very common
• 之前: very common, often slightly more explicit
• 以前: also correct, but it can have other meanings in other contexts, such as formerly

In everyday speech, many learners will hear 跑步前 and 跑步之前 very often.

Chinese often omits the subject when it is obvious or when the sentence is giving a general instruction.

So this sentence is like saying:

• Before running, warm up first.
• You should warm up before running.

The subject is understood from context, so it does not need to be stated.

This is very common in advice, instructions, and warnings.

Usually, yes, a comma is very natural after the time phrase:

跑步以前，先热身。

The comma helps separate:

• the background/time part: 跑步以前
• the main action: 先热身

Without the comma, the sentence is still understandable, but with it, the structure is clearer in writing.

Also, standard Chinese writing does not use spaces between words, so it would normally be written as:

跑步以前，先热身。

not

跑步 以前 先 热身。

Not always. 以前 has a few related uses.

Common ones include:

1. after an event/action phrase: before doing that

   • 跑步以前 = before running

2. when talking about the past: formerly / in the past

   • 我以前住在北京。 = I used to live in Beijing.

So the exact meaning depends on what comes before it and on the context.

In your sentence, because it follows 跑步, it clearly means before running.

The pronunciation is:

跑步以前先热身。
pǎobù yǐqián xiān rèshēn

Tones:

• 跑 pǎo — 3rd tone
• 步 bù — 4th tone
• 以 yǐ — 3rd tone
• 前 qián — 2nd tone
• 先 xiān — 1st tone
• 热 rè — 4th tone
• 身 shēn — 1st tone

A natural rhythm is:

跑步以前 / 先热身。

In connected speech, the 3rd tones are often not pronounced with a full dip, especially inside a sentence, so just aim for smooth, natural speech rather than over-pronouncing each tone separately.