Fetch! with Ruff Ruffman Season 1 Episode 17 Relaxin' with Ruff ( Air Date ) Genre Kids, Animation category. Overview "Ruff decides to calm down from the stresses of running a show. The kids learn to relax with yoga and to calculate heart rate (pulses in 15 sec * 4). Next, they mathematically measure their "fear factor" at Canobie Lake Park, an amusement park in New Hampshire.".