Our Leaper provides fast speed resistance safely and as fast as one can work. We also measure with our LCD's, one's total work through the full range of motion for any number of reps with our LCD readouts. Our automatic isokinetic resistance develops little to no muscle soreness. One may vary the speed of the from slow to fast or vice versa. On average, most athletes do 30 squats in 25-30 seconds with our fast speeds, and push 1000 lbs in the last couple inches of that exercise (something impossible with weights). Many basketball and girls volleyball players report gains of 4 to 12 inches in their vertical jump in just a matter of weeks. Everyone jumps higher, runs faster and jumps quicker for rebounding and spiking with our fast speed resistive exercise.