shinkokyuu toka sutoretchi toka no chiisana shuukan wa, shuuchuuryoku ga ochiruno o yobousuruno ni mo kenkou no tame ni mo yakuni tachimasu.

とか is a casual way to list examples and has a nuance of “things like …” or “for example …”.

• 深呼吸とか ストレッチとか ≈ “things like deep breathing, stretching, etc.”
• Repeating とか after each item is very natural in conversation and relaxed writing.

Comparison:

• AとB – “A and B” (a complete list; quite definite)
• AやB – “A and B (and possibly others)” (neutral, a bit more standard)
• AとかBとか – “A, B, and things like that” (casual, example-like feel)

So the double とか fits the friendly, non-technical tone of the sentence and suggests these are just examples of small habits, not a complete list.

Here の is the same の you see in patterns like 日本の文化 (“Japanese culture”) – it links a noun (or noun phrase) to another noun.

• Whole chunk: 深呼吸とか ストレッチとか の 小さな習慣
• Function: “[small habits] of things like deep breathing or stretching”

So the structure is:

• (深呼吸とか ストレッチとか) の 習慣
  • “habits of things like deep breathing or stretching”

You could think of it as:

• “small habits like deep breathing, stretching, etc.”

Grammatically, の is just marking that the whole “deep breathing, stretching, etc.” part modifies 習慣.

小さな and 小さい have almost the same meaning (“small”), but:

• 小さい is a regular い-adjective.

  • Before a noun: 小さい習慣
  • As a predicate: 習慣は小さいです。

• 小さな is a special attributive form used only before nouns:

  • 小さな習慣 (OK)
  • But you cannot say 習慣は小さなです (✕)

Nuance:

• 小さな often sounds a bit more literary, soft, or expressive.
• In practice, 小さい習慣 and 小さな習慣 mean the same thing here; the writer just chose the slightly more “story-like” or “gentle” expression 小さな.

は is marking 小さな習慣 as the topic of the sentence:

• “As for these small habits, they are useful for …”

If you used が:

• 小さな習慣が 役に立ちます。
  • This would emphasize “It is the small habits (and not something else) that are useful,” often introducing them as new, focused information.

With は, the sentence feels like a general statement or explanation about small habits, not a contrastive emphasis. That fits the idea of giving general advice about small habits.

落ちる is an intransitive verb here (“to fall, to drop, to decline”), so the thing that declines is its subject, marked by が:

• 集中力が 落ちる。
  “Concentration falls/declines.”

You normally do not use を with intransitive verbs like this because there is no direct object. Compare:

• 雨が降る。 – “It rains.” (rain is the subject)
• 値段が下がる。 – “The price goes down.” (price is the subject)
• テンションが上がる。 – “Energy/mood goes up.”

Same pattern: 集中力が落ちる → concentration is the thing that “falls,” so it takes が.

This の turns the whole clause 集中力が落ちる (“concentration falls”) into a noun-like phrase so it can take を and become the object of 予防する.

• Clause: 集中力が落ちる – “concentration falls / the concentration drops”
• Nominalized: 集中力が落ちるの – “the fact that concentration falls / the dropping of concentration”
• With を: 集中力が落ちるのを 予防する
  “to prevent the dropping of concentration”

So the pattern is:

• [Sentence in plain form] + の + を + verb

You could often replace の with こと here:

• 集中力が落ちることを予防する – also grammatical, slightly more abstract.
• の tends to feel a bit more concrete and is common in everyday speech.

Again, this の is a nominalizer. It turns the verb phrase 予防する (“to prevent”) into a noun-like chunk so that に can attach:

• 予防するのに ≈ “for preventing (it)” / “for the purpose of preventing it”

Structure:

1. 集中力が落ちるのを 予防する
   “to prevent concentration from falling”
2. Nominalize that action: 集中力が落ちるのを予防するの
   “the act of preventing concentration from falling”
3. Add に: 集中力が落ちるのを予防するのに
   “for the purpose of preventing concentration from falling”

So, V-plain + のに here means “for ~ing / in order to ~”.

Note: there is another grammar V-plain のに meaning “although / in spite of,” but in this sentence the presence of も and the parallel with 健康のために clearly show the “for the purpose of” meaning, not “although.”

にも is a combination of:

• に – “for, to, in”
• も – “also, too, even”

So:

• 予防するのに も – “also for preventing it”
• 健康のために も – “also for (the sake of) health”

The pattern:

A にも B にも 役に立ちます。
“It is useful both for A and for B.”

Without も, it would be:

• 予防するのに 役に立ちます。 – “It is useful for preventing it.”
• 健康のために 役に立ちます。 – “It is useful for your health.”

Adding も to both emphasizes “both A and B.”

健康のために literally means “for the sake of health” or “for your health / for health reasons”.

The pattern is:

• N のために – “for the sake of N, for N, for the benefit of N”
  • 家族のために働く – “work for the sake of one’s family”
  • 将来のために勉強する – “study for the future”

So:

• 健康のために – “for (the sake of) health”

If you just said 健康に:

• 健康に often means “in a healthy way” or “to become healthy,” e.g.
  
  • 健康に暮らす – “live healthily”
  • 体を健康にする – “make the body healthy”

Here, we’re talking about purpose/benefit, so 健康のために is the natural choice.

役に立つ literally means “to stand (立つ) into a role/use (役)”, so figuratively:

• “to be useful / to be helpful / to be of use”

The pattern is:

• N に 役に立つ – “be useful for N”
  • 日本語の勉強に 役に立つ本 – “a book that is useful for studying Japanese”
  • 仕事に 役に立つ経験 – “experience that is useful for work”

So in the sentence:

• … 予防するのにも 健康のためにも 役に立ちます。
  • “(They) are useful for preventing it and for your health.”

The に marks the target or area where something is useful.

Also note:

• 役に立つ (plain) → 役に立ちます (polite form)
• Synonyms:
  • 役立ちます – shorter, often written
  • ためになります – “good/beneficial for (you)” (more about personal growth)

In Japanese, many actions are expressed as noun + する:

• 深呼吸する – “to take a deep breath”
• ストレッチする – “to stretch (do stretching exercises)”

In the sentence, they appear as nouns inside a bigger noun phrase:

• 深呼吸とか ストレッチとか の 小さな習慣
  • “small habits like deep breathing or stretching”

So we’re naming the kinds of habits, not directly saying “do deep breathing” or “stretch” as verbs.

Examples as verbs:

• 朝起きたら、深呼吸をします。 – “When I get up, I take deep breaths.”
• 運動の前にストレッチをしたほうがいいです。 – “You should stretch before exercising.”

Yes. Broken into parts:

1. 深呼吸とか ストレッチとか の 小さな習慣 は、
   “Small habits like deep breathing or stretching,” (topic)

2. 集中力が落ちるのを 予防するのに も
   “also for preventing your concentration from falling,”

3. 健康のために も
   “also for your health,”

4. 役に立ちます。
   “are useful / are helpful.”

So the core frame is:

• A は、 B にも C にも 役に立ちます。
  “A is useful both for B and for C.”