Bullworker

Bullworker is a product and fitness company that specializes in isometric exercise, that is the static contraction of a muscle without any visible movement. The original portable home fitness device was invented by Gert F. Kölbel in 1962. The product enjoyed widespread popularity in the 1960s and 1970s during the personal fitness craze, but its popularity fell off in the 1980s when personal gyms became readily available. New models have been made available, and Bullworker is still marketed worldwide by different holders.

In the 1950s, German scientists Dr. Erich Albert Müller and Theodor Hettinger "observed that contractions involving less than about one third of maximum strength do not train the muscle. If the contraction of a muscle exceeds one third of its maximum strength, its mass grows and hence also its strength". Furthermore, it is said that he concluded that muscle growth can be attained by exerting 60% of existing muscle strength against a superior resistance for only seven seconds once a day, a fitness technique known as isometrics. The study at the Max Planck Institute consisted of over 200 experiments over a ten year period. Theodor Hettinger published his book Physiology of Strength. They both developed a training program based on isometrics exercise. In the 1960s, professor James A. Baley put isometrics to the test with a class of 104 college students at the University of Connecticut. The Bullworker manual claimed that study resulted in the isometric training group improving three times faster than the sports training group on tests measuring increases in strength, endurance, coordination, and agility. However, the original article is far more complex even if it showed significant gains after a 4 week program of isometric exercises.

Bullworker enjoyed widespread popularity in Europe and the United States in the 1960s and 1970s during the personal fitness craze. Various charts were then introduced, proposing different work to exercise and develop the muscles.

Though Bullworker's popularity fell off in the 1980s when personal gyms became readily available, new models had been created by Hughes Marketing, LLC: the Bullworker Bow Classic and the Bullworker Steel Bow. The Bow Classic is long, and is the Bullworker 'barbell' equivalent, specializing in powerful holds and greater range of motion. The Steel Bow is long and is the Bullworker dumbbell specializing in versatility for muscle targeting and travel. Both Bullworker models have interchangeable springs to easily change resistance levels, ranging from approximately 0–60 kg (0 130 lbs) of resistance. The original Bullworker suggested 26 individual exercises. While isometrics was the emphasis, the instructions included isotonic, cardio, resiliency and endurance routines. The emphasis on these additional functions greatly expanded the number of exercises available. An additional fitness routine of Iso Motion has since been added. Bullworkers are well built and very durable; many early units remain in regular fitness use decades later.

In the movie Never Say Never Again, James Bond uses a Bullworker as a weapon against Lippe. The biographical page of Gert F. Kölbel claims that among famous users were: Franz Beckenbauer, Konrad Adenauer and Muhammad Ali. A photograph exists showing a Bullworker behind Bruce Lee. Dave Prowse, who played Darth Vader, used to be a commercial consultant to sell the Bullworker in the United Kingdom.