yǔqí zài gāofēngqī yòng pǎobùjī, bùrú xiān shàng yújiā kè.

It is a very common comparison/preference pattern meaning something like:

• rather than A, it’s better to B
• instead of A, one might as well do B

In this sentence, 与其在高峰期用跑步机，不如先上瑜伽课 presents two options:

• option A: using the treadmill during peak hours
• option B: taking a yoga class first

The speaker is saying B is the better choice.

A useful way to remember it is:

• 与其 + option you are rejecting
• 不如 + option you recommend

It is not extremely formal, but it is a bit more structured and polished than very casual everyday speech. It is completely natural in conversation, writing, advice, and commentary.

In very casual speech, someone might also say things with similar meaning using other patterns, but 与其……不如…… is a standard, useful pattern that learners should know well.

在 here introduces a time or situation frame: during / in / at peak hours.

So:

• 在高峰期 = during peak hours

Chinese often uses 在 + time/situation to set the context for the action.

Examples:

• 在周末 = on weekends
• 在晚上 = in the evening
• 在高峰期 = during peak time

In this sentence, 在高峰期 tells you when the treadmill use would happen.

高峰期 literally means peak period. It is used for times when something is busiest, most crowded, or most intense.

Depending on context, it can mean:

• rush hour
• peak time
• the busiest period

In a gym context, 高峰期 probably means the time when the gym is crowded and equipment is harder to get.

So it is broader than just traffic rush hour; it can be used for many kinds of busy periods.

用 means to use. Since 跑步机 is a machine, 用跑步机 is the natural way to say use the treadmill.

That is different from saying:

• 跑步 = to run
• 在跑步机上跑步 = to run on a treadmill

So:

• 用跑步机 focuses on using the machine
• 在跑步机上跑步 focuses more specifically on running on it

Both could work in some contexts, but 用跑步机 is shorter and natural here.

Yes, you could, and it would be very understandable.

Compare:

• 在高峰期用跑步机 = use the treadmill during peak hours
• 在高峰期在跑步机上跑步 = run on the treadmill during peak hours

The second version is more explicit about the activity. The original is a little more compact.

One small style point: Chinese often prefers avoiding too many repeated location markers like 在……在……, so the original sentence sounds cleaner.

In Chinese, 上课 means to attend class or to go to class. Because of that, 上 is commonly used with many kinds of lessons or courses:

• 上课 = attend class
• 上中文课 = take a Chinese class
• 上瑜伽课 = take a yoga class

This may feel strange to English speakers because 上 often means up or go up, but in this pattern it has a special verb use meaning attend.

So 上瑜伽课 is the normal way to say take a yoga class.

Yes, but the meaning changes slightly.

• 上瑜伽课 = take a yoga class
• 练瑜伽 = practice yoga
• 做瑜伽 = do yoga

So if the point is specifically joining a class, then 上瑜伽课 is best.

If you only mean the activity itself, not necessarily in a class setting, then 练瑜伽 or 做瑜伽 could be used.

The original sentence specifically recommends taking a class first, not just doing yoga in general.

先 means first.

It shows sequence: before doing something else, do this one first.

So 不如先上瑜伽课 means:

• it would be better to take a yoga class first

In Chinese, 先 usually goes before the verb phrase it modifies:

• 先吃饭 = eat first
• 先休息 = rest first
• 先上瑜伽课 = take a yoga class first

It tells you the recommended order of actions.

Chinese often omits the subject when it is obvious from context.

So even though English often wants something like:

• Rather than use the treadmill during peak hours, you should take a yoga class first

Chinese can simply say:

• 与其在高峰期用跑步机，不如先上瑜伽课。

The subject could be:

• you
• we
• one
• or whoever is being discussed

Chinese relies heavily on context, so omitted subjects are very common and natural.

No. They often do not have to be complete sentences with repeated subjects.

Chinese commonly leaves out repeated information when it is understood.

In this sentence, both halves are just action phrases:

• 在高峰期用跑步机
• 先上瑜伽课

The subject is understood to be the same in both parts.

You can also have fuller versions, such as:

• 与其你在高峰期用跑步机，不如你先上瑜伽课。

But this sounds more repetitive than necessary in normal speech.

By itself, 不如 often does mean not as good as or not equal to:

• 他不如你高。 = He is not as tall as you.
• 这个不如那个好。 = This one is not as good as that one.

But in the pattern 与其……不如……, it takes on a more idiomatic meaning:

• rather than A, it’s better to B

So here, 不如 is not just a simple comparison word; it is part of a fixed structure expressing a recommendation or preference.

Chinese usually prefers time expressions before the main verb phrase.

So this order is most natural:

• 在高峰期用跑步机

This follows a common Chinese word-order tendency:

• time + verb phrase

For example:

• 我晚上学习。 = I study in the evening.
• 他周末去健身房。 = He goes to the gym on weekends.

You might sometimes hear other orders in special contexts, but 在高峰期用跑步机 is the normal, natural phrasing.

Yes, it helps show the two-part structure of 与其……不如…….

• first part: the less preferred option
• second part: the better option

So the comma makes the contrast clearer:

• 与其在高峰期用跑步机，不如先上瑜伽课。

In speech, there is usually a slight pause there too.

Here 瑜伽课 is a noun phrase meaning yoga class.

• 瑜伽 = yoga
• 课 = class / lesson

So 上瑜伽课 literally means attend a yoga lesson/class.

In this sentence, 课 is not acting like a measure word. It is part of the object noun phrase.

If you wanted to count classes, then you would need a measure word:

• 一节瑜伽课 = one yoga class

So:

• 上瑜伽课 = take yoga class(es)
• 上一节瑜伽课 = take one yoga class

It sounds mainly like advice or recommendation.

The sentence does compare two choices, but the practical effect is:

• Option B is smarter / more efficient / more worthwhile than option A

It does not necessarily criticize treadmill use itself. The point is that during peak hours, taking a yoga class first is being presented as the better choice.

So the tone is usually:

• practical
• suggestive
• mildly persuasive

rather than harsh or judgmental.