The Bullworker devices are available at a variety of venues, most notably at their official site. Here you will find a variety of products available, from the devices themselves to supporting literature, customer testimonials, and a blog you may wish to peruse. You can also find tips on combining this primarily isometric form of exercise with what some may consider the more common isotonic forms.
Isometric Steering Wheel Push – Start by placing your hands on the steering wheel, 9 and 3 is the best position. Start by placing your hands in position and pushing against the steering wheel. As you push, hold the contractions in your chest and shoulders for at least 30 seconds. You can do as many sets of these as you feel comfortable doing.
Today, I read online about Isometrics by Henry Wittenberg. In 1948, he was an Olympic champion and later an instructor and coach. I think the book was written in the early 1960’s. The book demonstrates many 15 minute workouts like isotonic exercises, warm-up, and isometrics. I believed that if people stick with these workouts, they could get the better overall shape.