This is an installment of Good Fit, a column about exercise. At Form Fitness, in Brooklyn, you’ll find an assortment of squat racks, dumbbells, and pull-up bars—which is to say, it’s a typical gym.

I wake up in the morning and look in the mirror. I shower and do my hair and makeup in front of a vanity mirror, then get dressed with the help of my full-length mirror. I have three mirrors in my ...

The importance of positive mirroring in infant development is well established. Most therapists are introduced to developmental mirroring by studying Jacques Lacan, D.W. Winnicott, or Heinz Kohut.