This is the 4070th most frequent Japanese word.
フィット
"Fit" (suitability or compatibility; can also mean physical fitness).
In this sentence, 'フィット' is used to describe fitting closely or suitably to an object, which are the shoes and feet in this case.
この靴は私の足にぴったりフィットします。
These shoes fit my feet perfectly.
Here, 'フィット' refers to matching or being appropriate for a specific context, which is the yoga class.
私は新しいヨガクラスにフィットするトレーニングウェアを買いました。
I bought workout clothes that fit the new yoga class.
In this usage, 'フィット' describes suitability or appropriateness of abilities to requirements.