En el gimnasio siempre llevo una toallita y un poco de gel en la mochila.

Because it sets the context first: at the gym.

Spanish often puts a place expression at the beginning when the speaker wants to frame the whole sentence:

En el gimnasio siempre llevo... = At the gym, I always carry...

This does not mean the speaker is physically carrying those things only while standing inside the gym. It can simply mean that, for gym use, they always have those items with them.

A more neutral order would also be possible:

Siempre llevo una toallita y un poco de gel en la mochila en el gimnasio.

But the original sounds more natural because it introduces the setting first.

Here, llevar means to carry, to have with you, or to bring along.

So siempre llevo una toallita y un poco de gel means:

• I always carry a small towel and some gel
• I always have a small towel and some gel with me

In everyday Spanish, llevar is very common for talking about things you keep on you or in a bag:

• Llevo el móvil en el bolso. = I carry / keep my phone in my bag.
• Siempre llevo agua. = I always carry water.

This is a very common question.

• llevar = to take / carry something away from a reference point, or simply to have it with you
• traer = to bring something toward a reference point

In this sentence, the focus is not on bringing the items to the listener or to the current place of speaking. It is just saying that the speaker has those things with them at the gym. So llevo is the natural choice.

Compare:

• Siempre llevo una toallita en la mochila.
  = I always carry a small towel in my backpack.

• Siempre traigo una toallita al gimnasio.
  = I always bring a small towel to the gym.

Both can work, but they focus on slightly different things.

Toallita is the diminutive form of toalla.

• toalla = towel
• toallita = small towel, little towel, or sometimes wipe, depending on context

The ending -ita often suggests one of these ideas:

• small size
• affection
• informality
• something light or handy

In a gym context, toallita often suggests a small towel used to wipe sweat, rather than a full-sized bath towel.

So:

• una toalla = a normal towel
• una toallita = a small towel / little towel

Because toallita is a countable noun, while gel is usually treated as an uncountable substance.

You can count towels:

• una toallita
• dos toallitas

But you normally do not count gel as separate units unless you specify a container:

• un poco de gel = a little gel / some gel
• un bote de gel = a bottle of gel

So the grammar changes depending on whether the noun is countable or not.

Both are possible, but un poco de gel sounds more natural if you mean a small quantity of gel.

Compare:

• llevo gel = I carry gel
  This is grammatical, but more general.

• llevo un poco de gel = I carry a little gel / some gel
  This emphasizes that it is just a small amount.

This is very common with uncountable nouns:

• un poco de agua = a little water
• un poco de crema = a little cream
• un poco de perfume = a little perfume

Because gel is a masculine noun in Spanish.

So you say:

• el gel
• un gel
• un poco de gel

This is just something you need to learn with the noun. Not all nouns ending in consonants have obvious gender, so it is best to memorize them with the article:

• el gel
• la crema
• el champú

Because that is a very natural position for adverbs like siempre.

In Spanish, adverbs of frequency often go:

• before the verb
  Siempre llevo...
• or sometimes after the verb, depending on emphasis
  Llevo siempre... — possible, but less neutral here

The most normal version is:

En el gimnasio siempre llevo...

That sounds like: At the gym, I always carry...

Because they refer to two different kinds of location:

• En el gimnasio = at/in the gym → the general setting
• en la mochila = in the backpack → where the items are kept

So the sentence means:

At the gym, I always carry a small towel and some gel in my backpack.

Using en twice is completely normal in Spanish when you need two location phrases.

Normally, it is understood as applying to both items:

I always carry a small towel and some gel in my backpack.

In other words, both the towel and the gel are in the backpack.

Technically, because of word order, a learner might wonder if it only attaches to the second item. But in normal usage, speakers understand it as referring to the whole list.

If someone wanted to make it extra clear, they could say:

En el gimnasio siempre llevo en la mochila una toallita y un poco de gel.

That structure makes it even clearer that both things are in the backpack.

Because en el gimnasio expresses location, while al gimnasio expresses movement toward the gym.

• en el gimnasio = at/in the gym
• al gimnasio = to the gym

Compare:

• En el gimnasio siempre llevo una toallita...
  = At the gym, I always carry a small towel...

• Siempre llevo una toallita al gimnasio.
  = I always take/bring a small towel to the gym.

So the choice depends on whether you want to express where or to where.

On its own, gel can mean different kinds of gel depending on context, such as:

• shower gel / body wash
• hair gel
• sometimes hand sanitizer

In a gym sentence, many Spanish speakers would probably understand it as something like shower gel or maybe a toiletry product you keep in your bag.

If you want to be specific, you can say:

• gel de ducha = shower gel
• gel para el pelo = hair gel
• gel hidroalcohólico = hand sanitizer

So gel is a bit general by itself, and context does the work.

Yes, absolutely.

• una toalla = a towel
• una toallita = a small towel / little towel

Using toallita makes the sentence sound a bit more natural if you mean a small gym towel rather than a large towel for showering.

So the choice depends on the image you want to give:

• Siempre llevo una toalla... = I always carry a towel...
• Siempre llevo una toallita... = I always carry a little towel...

Yes, in natural English both can work depending on context.

Because llevar often means to have with you, the most direct idea is:

• I always carry a small towel and some gel in my backpack.

But in some contexts, English speakers might also say:

• I always bring a small towel and some gel in my backpack to the gym.

That is why llevar can feel broader than a single English verb. Depending on context, it may match:

• carry
• take
• bring
• have with you

Here, carry is probably the clearest choice.