<entry id="2292045" stat="A" corpus="jmdict" type="jmdict">
<ent_corp type="jmdict">jmdict</ent_corp>
<ent_seq>2860215</ent_seq>
<k_ele>
<keb>ＨＩＩＴ</keb>
</k_ele>
<r_ele>
<reb>ヒート</reb>
</r_ele>
<r_ele>
<reb>ヒット</reb>
</r_ele>
<sense>
<pos>&n;</pos>
<gloss>HIIT (exercise regimen)</gloss>
<gloss>high-intensity interval training</gloss>
</sense>
<info>
<audit time="2024-02-17 09:15:23" stat="A" unap="true">
<upd_name>Brian Krznarich</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>Saw flyers and posters for classes at Shinjuku Ward Sports Center as HIIT with ヒート furigana. ヒット also appears online. Has value as an entry because the pronunciations are novel. Wikipedia doesn't even include the readings, interestingly. Almost certainly not エイチ・アイ・アイ・ティー.

If you want to be strict about etymology, I suspect ヒット is indeed from English "hit"(video ref), while ヒート is a native interpretation of the acronym.</upd_detl>
<upd_refs>話題のメソッド「HIIT」とは？
https://www.nas-club.co.jp/magazine/hiit
近年、「HIIT（ヒート・ヒット）」というトレーニング方法...

高強度インターバルトレーニング seems significantly more common online then when the ngram database was collected. Could add if interested.
高強度インターバル	20

https://ja.wikipedia.org/wiki/%E9%AB%98%E5%BC%B7%E5%BA%A6%E3%82%A4%E3%83%B3%E3%82%BF%E3%83%BC%E3%83%90%E3%83%AB%E3%83%88%E3%83%AC%E3%83%BC%E3%83%8B%E3%83%B3%E3%82%B0
高強度インターバルトレーニング（こうきょうどインターバルトレーニング、英: High-intensity interval training, HIIT）とは、

Apparently sometimes called "hit training" in English, which explains the ヒット alternate. (video, sound)
https://youglish.com/pronounce/HIIT%20training/english/uk</upd_refs>
</audit>
<audit time="2024-02-17 21:53:38" stat="A" unap="true">
<upd_uid>stephen</upd_uid>
<upd_name>Stephen Kraus</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>Maybe this works.</upd_detl>
<upd_refs>https://en.wikipedia.org/wiki/High-intensity_interval_training
The wiki article frequently describes this as an exercise regimen.</upd_refs>
<upd_diff>@@ -15,2 +15,2 @@
-&lt;gloss&gt;HIIT&lt;/gloss&gt;
-&lt;gloss&gt;High Intensity Interval Training&lt;/gloss&gt;
+&lt;gloss&gt;HIIT (exercise regimen)&lt;/gloss&gt;
+&lt;gloss&gt;high-intensity interval training&lt;/gloss&gt;</upd_diff>
</audit>
<audit time="2024-02-18 01:21:03" stat="A">
<upd_uid>jwb</upd_uid>
<upd_name>Jim Breen</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>Probably as good as we'll get.</upd_detl>
</audit>
</info>
</entry>