A perfect method for finding the right weight to lift when doing a leg press doesn't exist. The strength of your legs varies depending on your overall fitness, exercise regimen and physiology. While you can use a calculator to determine how much you should lift, a basic trial also offers insight into how much weight a beginner should leg press.
Factor of Body Weight
Lifting a weight based on your body weight is one means of determining how much to lift. The University of Texas at Austin reports ranges for men and women between ages 18 and 29. The university's data say that the lowest percentile of women completing a leg press is 1.79 times their body weight and the lowest percentile of men completing a leg press is 2.47 times their body weight. At the highest level, women press 3.71 times their body weight and men press 4.84 times their body weight.
Trying Out a Weight
Another method involves sitting down with a trainer at the leg press to find your maximum. To do this, warm up for five to 10 minutes. Rest for one minute. Seat yourself in the press and select a weight you can comfortably press three to fives times by adding 30 pounds to 40 pounds. Rest for two minutes. Then increase the weight to near your maximum by adding an additional 30 pounds to 40 pounds Press two to three times. Rest for two to four minutes and increase the weight by 10 to 20 percent or 30 pounds to 40 pounds. Press one time. If you can't press that weight, then you've found your maximum load. If you can press the weight, increase again by 10 to 20 percent until you can't complete a leg press. Rest for two to four minutes after each increase.
Form is important when completing a leg press properly. Press your back and tailbone against the supporting pad before you start the press. Keep your feet parallel, not pointed out, on the pad and keep your heels flat so they don't drop below the pad. Adjust the position of the seat so that your knees don't bend beyond 90 degrees when you begin the press. Use the side bars to gently support your upper body and brace your core to start. Press until your leg is extended, but not so far that you lock out your knees, which can hyperextend and injure them. Do not lift your bottom or round your back.
Leg presses target your lower body, working primarily your gluteal muscles, which are the muscles of your bottom; the quadriceps at the front of your thigh; and the hamstrings at the back of your thigh. You also workout the calf muscle called the gastrocnemius when pressing the weight. In addition, leg presses give you the opportunity to lift a heavy weight. Start with a weight you can comfortably lift for eight to 12 repetitions, increasing the weight every six weeks as you establish your workout routine.