Early History & Findings

Bullworker, a fitness company and product, specializes in isometric exercise, the fastest known technique for strength training, originally marketed and sold in the early 1960’s. Designed and patented by German inventor Gert F. Kölbel, it continues to sell around the world including in Europe, Asia, and the United States.

The most significant breakthrough in fitness came when the German scientists Dr. Erich Albert Müller and Dr. Theodor Hettinger discovered maximum muscle growth can be attained by exerting 60% of existing muscle strength against a superior resistance for only 7 seconds once a day, a remarkable fitness technique known as isometrics. The study at the Max Planck Institute consisted of over 200 experiments over a ten-year period. Optimum results are attained with 5 workouts per week, but impressively, even one single weekly workout is sufficient to maintain your improvements attained.

Professor James A. Baley put isometrics to the test with a class of college students at the University of Connecticut. The 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.

In 1962 Bullworker pioneered portable home fitness devices and the 7 second isometric exercise for the fastest strength gains using both contraction and extension movements involving range of motion for all the major muscle groups in one light weight and compact fitness tool at a price everyone could afford.

Bullworker exploded on the fitness scene revolutionizing exercise for muscle strength to be more effective and much faster.

The original Bullworker consists of two sleeved, spring-loaded, telescopic cylinders in the center, with two hand grips affixed at the outermost ends. Two opposing cables are attached to the hand grips at each end of the device. The apparatus weighs about four lbs (1.8 kg). Exercises are performed by pushing inwards on the contractible cylinders or by pulling the cables outwards, away from the cylinders. The resultant compression of the internal spring creates the desired resistance; the Bullworker returns to its original position when pressure is released. A range of up to 150 lbs (68 kg) or more of resistance is possible.


A number of improvements have been made to the Bullworker since its introduction but the concept remains the same. It is marketed worldwide, with trademarks and distribution owned by Hughes Marketing, LLC. There are two models, the Bow Classic and Steel-Bow. The Bow Classic is 36″ long and is the Bullworker barbell specializing in powerful holds and greater range of motion. The Steel-Bow is 20″ long and is the Bullworker dumbbell specializing in versatility for muscle targeting and travel. Both have interchangeable springs to easily change resistance levels, ranging from approximately 0-130 lbs (0-60 kg) of resistance.

The original 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 use.

Bullworker has developed a fitness product line specializing in convenient exercise to improve strength and flexibility for everyday performance. The Pro System is a complete cross training home gym including the Bow Classic, Steel Bow, Iso-Gym, Iso-Bow, and Bow Extensions

Bullworker’s Mission:

Make fitness simple and improve quality of life.

See also[edit]

  • Dynamic Tension
  • Isometrics


  • Bullworker History
  • India Today Bullworker Article
  • Bullworker training program

Source: https://en.wikipedia.org/wiki/Bullworker

Sports and Fitness