Unlike the dept. store brand of grippers you can do endless reps with, our grippers were designed to give you a solid resistance work-out by doing low repetitions.(squeezing the grippers less than 5 to 15 times for work sets). Many new consumers make the mistake of over-training and use their Heavygrips everyday which can cause injury due to overtraining. Just as you would not bench press or squat heavy weights 4 or 5 times per week, you should not train low reps with your Heavygrips that often.