Mats Thulin, a Swede who brought Nautilus equipment to his country in the 1980s, has worked for almost a decade to find a way to construct an exercise machine that would make negative-accentuated training simple, safe, and productive.


    "It finally hit me!" Mats remembered. "What if I tilt the weight stack during the upper movement and return it to the vertical during the downward phase?"


    Subsequent experiments by Mats demonstrated the value of his tilted weight stack and eventually led to the design of successful equipment.


    X-Force is the name of the patented series of machines for negative-accentuated training. The machines feature radically different construction, which makes their feel unique but, at the same time, understandably familiar for radically better results.


    The idea is simple: A weight stack that, when a trainee begins a positive stroke, automatically tilts to 45 degrees. As he shifts to the negative, the weight stack automatically tilts back to the vertical.


    This means that the weight increases significantly in the negative phase. For example: 100 pounds of resistance in the positive, transitions to 140 pounds for the negative. On any X-Force machine, the negative motion is always 40-percent heavier.

    X-Force puts the exerciser in control. No spotters or assistants are required to help do the lifting. There’s no chance of missing a handoff and risking an injury. The training experience is the same as with conventional machine, with smooth movements.
    The overall benefit is greater muscular stimulation plus time saved. X-Force’s negative-accentuated training places heavier loads on the muscles, so more recovery days between workouts are required.
    The X-Force AB is a Swedish company located in Stockholm, Sweden. X-Force works in close collaboration with Mastec Lpi and Hareide Design Mill: X-Force’s production and design partners, respectively.
    The International Health, Racquet & Sports Club Association (IHRSA) is a not-for-profit trade association representing health and fitness facilities, gyms, spas, sports clubs, and suppliers worldwide. The association’s membership includes over 9,750 clubs in 78 countries, along with over 740 industry suppliers.