長岡望悠のインスタグラム(nagaokamiyu1) - 9月8日 22時14分

In the video, Miyu explains why using the belt.
Interviewer: what do you use this square object like a belt around your waist?

Miyu: This is a machine which measures the heart rate. The result goes directly to the IPad. If the heart rate shows 75-80%, the result which comes out that the performance of the players are up.

#ミユ #みゆ #ながおか #miyu #nagaoka #1 #nippon #japan #長岡望悠 Translation: @長岡望悠

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