## How to estimate your 1RM

As you know, 1RM means one repetition maximum. It represents the maximum weight a group of muscles can lift one time (or resistance they can overcome).Because beginners should begin gradually (without heavy lifting), a modified method developed to allows you to determine your 1RM without overexerting your muscles. The results you get will allow you to see how strong you are.

The modified 1RM can be done with free weights or machines, but the instructions that follow will be for machine use. Resistance machines are recommended for these self assessments, especially for beginners, because they are safer. Two tests are used most often, and the ones performed in this self-assessment activity are for the upper body (arm press) and the lower body (leg press). If a person performing the arm press on a resistance machine can lift 50 pounds one time, but not more than one time, this number would represent the 1RM for the arm press. Similarly, if the person could move a resistance of 150 pounds one time with the leg press, but not more than one time, 150 would the 1RM for the leg press. As mentioned earlier in this chapter, 1RM scores for the arm press and leg press will be estimated to avoid maximal lifting, something that is discouraged for teens.

Follow these directions for each of the two self-assessments:

* Choose a weight (resistance) that you think you can lift 5 to 10 times but is too heavy for you to lift more than 10 times. Do not use a weight that you can lift fewer than 5 times.

* Using correct technique, lift the weight as many times as you possibly can. Count the number of lifts and write the number on your record sheet. If you were able to do more than 10 lifts, wait until another day before you try a heavier weight for that exercise. Go to the next muscle group exercise.

* If you can tell that you will not be able to lift the weight at least 5 times, stop and choose a lighter weight.

* If you were able to do 5 to 10 lifts and no more, then refer to table 11.1. Find the weight you lifted in the left-hand column. Now find the number of reps you did in the top row. Your 1PM score is the number in the box where the horizontal weight row and the vertical rep column intersect.

* Divide each of the two 1RM scores by the weight of your body to get a strength per pound of body weight score. The strength per pound of body weight score adjusts for body size (relative strength). For example, a person weighing 150 pounds and has a 1PM of 100 pounds on the arm press has a score of .67 pounds per pound of body weight. Use tables 11.2 and 11.3 to determine your fitness rating. Fitness ratings are only determined for the arm and leg press.

* If time allows, perform this procedure to determine your 1RM for other exercises included in the activity at the end of this chapter. Do the 1RM self-assessment for as many exercises as time allows. You do not need to determine a strength per pound of body weight score for these exercises. Use the 1RM scores to help you determine how much resistance to use for your PRE program.

**Safety Tips:** Proper form is essential for safety. Before you do the 1RM test, read the descriptions of the exercises and the directions that follow. Before performing the assessment, practice each of the two exercises and have a teacher check your form.

**Predicted 1RM Based on reps to Fatigue**