Cork varieties provide more lift and support because they’re heavier and more durable, says Ariel Kiley, a yoga instructor at Equinox locations in New York City. If you feel tight, placing one under your hand in a pose such as Half Moon allows you to reach full expression while touching a surface that’s firm enough to ground you.
Foam blocks are lighter and softer, making them great for initiating micro-contractions. Put one in between your thighs during Bridge or Camel, for example, to engage the inner-thigh muscles without added weight.
THE BOTTOM LINE
Use foam blocks when you need them to help activate a particular muscle or when you’re holding a restorative posture for several minutes. If you’re using the tool for stability, opt for cork.