It is important to understand this is a training harness, that is, it is designed to use for teaching dogs that walking without tension on the leash is ideal. (wileypup.com)
It is best to walk with the dogs on a loose or soft leash so that there is no pressure of tension on the leash from the handler. (apromisedlandrescue.org)
Don't put tension on the leash, get tense or talk to your in worried manner. (pethelpful.com)