The XS1 is designed for use by only one person at a time. Keep others, especially small children and pets, away from the device. Digital weight can sometimes feel heavier than free weight, so the best practice is to start lighter than your expected strength and do several reps to get a better feel for digital tension. Another best practice is to ensure that your deck lifting movement is straight up and down. For optimum position, ensure proper foot placement on the force plate to create this purely vertical cable path.