Does your workout H.I.R.T? High Intensity Resistance Training (H.I.R.T) is a hybrid of strength training and cardio that is designed to build muscle, burn fat, and challenge your body like never before; all in about 15 minutes. See an example of a H.I.R.T workout in the Videos section. Also be sure to check out our schedule of Free Fitness Classes to see about the next H.I.R.T. class near you.