Demanding exercise is what stimulates positive change. Well designed exercise equipment will often use changes in leverage to make exercise more demanding and, interestly at the same time, safer.
Wedge a crowbar under a heavy object and apply pressure at the very end of the crow bar. Your leverage decreases and difficulty level rises as you place your hands closer and apply pressure to the heavy object. MedX exercise equipment (the kind we use at our Austin Fitness Training facility) utilizes the same principle; while the weight stays the same throughout the range of motion, the leverage and difficulty level change.
Throughout a muscle's range of motion there will be points where the muscle is weaker and other parts of the range where the muscle is stronger. A muscle is more effectively fatigued when it works against a resistance it can barely handle at every part of its range of motion. MedX equipment is engineered so that the resistance increases when you are in the strongest part of your range of motion and decreases when you are in the weakest part (the sticking point). As a result you can eliminate thedangerous acceleration needed to get past that sticking point and complete the movement. It's a safer way to exercise.
The elimination of explosive accelerating movements obviates the need for warm-up sets. Demanding work produces change not warm-up sets. With MedX equipment you can confine your workout to safe, efficient, productive, demanding work. If you exercise in such a manner with minimal time between exercises you will find that in 20 to 30 minutes your muscles will be totally exhausted and your heart will be pounding. It produces an endorphin-inducing natural high. You’ll feel better, and with rest and recovery, you will come back stronger with more endurance.