במתיחה הזאת משתמשים בגומיית התנגדות.

ב־ is the preposition in / during / with, and in Hebrew it often attaches directly to the following word.

So:

• מתיחה = stretch
• במתיחה = in this stretch / during this stretch

In exercise instructions, ב־ often has a broad meaning. Here it is not literally “inside a stretch,” but more like in the case of this stretch or for this stretch.

In Hebrew, demonstratives like this usually come after the noun.

So:

• המתיחה הזאת = this stretch
• literally: the stretch this

That is normal Hebrew word order. English says this stretch, but Hebrew says the stretch this.

Because מתיחה is a feminine singular noun, and the demonstrative has to agree with it.

Agreement here is:

• זה = this, masculine singular
• זאת / זו = this, feminine singular

Since מתיחה is feminine, Hebrew uses הזאת.

When Hebrew says this/that after a noun, the noun normally takes ה־.

So you get:

• המתיחה הזאת = this stretch
• not usually מתיחה הזאת

This is different from English, where this stretch does not need the.

This is a very common Hebrew pattern. משתמשים is grammatically masculine plural, but it is often used impersonally.

So it can mean:

• people use
• you use
• one uses
• it is used

depending on context.

In instructions, Hebrew often avoids directly saying you and instead uses this general plural form. So משתמשים here is best understood as you use or people use in this stretch.

The dictionary form is להשתמש = to use.

משתמשים is the present tense masculine plural form:

• אני משתמש / משתמשת = I use / am using
• הוא משתמש = he uses
• היא משתמשת = she uses
• הם / אתם משתמשים = they / you use

Here it is not really referring to a specific group of men; it is just the standard plural form used for a general instruction.

Because the verb להשתמש normally goes with the preposition ב־.

So Hebrew says:

• להשתמש ב... = to use ...

Examples:

• להשתמש בעט = to use a pen
• להשתמש בטלפון = to use a phone
• להשתמש בגומיית התנגדות = to use a resistance band

This is just how the verb works in Hebrew. In English, use takes a direct object, but in Hebrew להשתמש usually takes ב־.

Because it is in a construct form (called סמיכות in Hebrew), where one noun is linked to another noun.

The basic noun is:

• גומייה = band / rubber band

But before another noun, it becomes:

• גומיית ... = band of ...

So:

• גומיית התנגדות = resistance band
• literally: band of resistance

This change is very common with feminine nouns.

It is a noun + noun phrase, often called a construct chain.

Structure:

• גומיית = band of ...
• התנגדות = resistance

Together:

• גומיית התנגדות = resistance band

English often puts the describing noun first, as in resistance band. Hebrew often links the two nouns in the opposite direction: band of resistance.

Because the sentence means a resistance band, not the resistance band.

So the phrase is indefinite:

• בגומיית התנגדות = with a resistance band

If it were definite, you would expect something like:

• בגומיית ההתנגדות = with the resistance band

In your sentence, the meaning is general, so the indefinite form is natural.

Because גומיית התנגדות is not a direct object here. It comes after the preposition ב־, because the verb is להשתמש ב־.

Compare:

• אני רואה את הספר = I see the book
  here את marks a definite direct object

but:

• אני משתמש בספר = I use the book
  here there is no את, because the noun follows ב־

So בגומיית התנגדות does not take את.

No. It is not passive grammar. It is an active impersonal form.

So the idea is not literally a resistance band is used, even though that is a possible English translation. The Hebrew form actually means more like:

• people use a resistance band
• you use a resistance band
• one uses a resistance band

Hebrew often prefers this kind of impersonal active wording in instructions.

Yes. הזו and הזאת both mean this for feminine singular nouns.

So both are possible:

• במתיחה הזאת
• במתיחה הזו

הזאת can sound a bit fuller or slightly more formal, while הזו is very common in everyday speech. Both are correct.

All three help capture the idea, depending on context.

Most naturally in English exercise language, this sentence means something like:

• In this stretch, you use a resistance band
• For this stretch, a resistance band is used

So ב־ here is broader than a simple physical in. It introduces the exercise context: when doing this stretch.

Hebrew often puts the context first. Starting with במתיחה הזאת tells you right away which exercise the sentence is talking about.

So the structure is:

• במתיחה הזאת = in this stretch
• משתמשים בגומיית התנגדות = people use / you use a resistance band

This is a very natural word order in Hebrew, especially in explanations or instructions.