by Charles T Ridgely
In part 1 we explained a proper way to test your max repititions. Below we will explain the proper way to record results on a graph.
Now that you know some of your RMs, you’ll need to plot them on a graph. This graph will express the weights you can lift in terms of the number of repetitions you can perform with those weights. Begin by drawing two lines; a vertical axis and a horizontal axis, as shown below. Label the vertical axis “Weight (lbs)” and the horizontal axis “Reps.” To be thorough, you should title the graph “Weight vs. Reps.”
It’s a good idea to date your graph. As your performance changes over time (e.g., you are able to lift more weight for more reps), the information you enter in the graph will need to be updated, accordingly. Although this may seem like a lot of work, the beauty of the graphing approach is that it will give you fairly accurate, individualized results every time. The next step is to break each axis into a series of equal segments that represent values along each of the axes. That way, you can use the axes for recording the weights you can lift and the numbers of reps you can perform with those weights. An example of this is shown in the graph below. As you can see, the Reps axis is broken into ten equal segments, each of which representing two repetitions. This enables you to record the number of reps you perform with a given weight. The Weight axis is a bit more tricky, and depends on the particular exercise you are analyzing and the weights you can lift for a variety of repetition values. Let’s consider an example that keeps things simple. Suppose you know you are capable of bench pressing 160 lbs for 8 reps and 140 lbs for 13 reps. Thus, you know your 8RM and 13RM for the Bench Press. But we want to know essentially all of your RMs, all the way from your 1RM to, say, your 20RM. Because of this, we need the Weight axis to include enough weight values to accommodate all of the weights you can possibly lift for this exercise. In this example, therefore, let’s have the Weight axis start at 60 lbs and finish at 200 lbs. Our graph then looks like this:
As you can see, each segment along the Weight axis represents a weight of 20 lbs. Note that we have omitted
weight values less than 60 lbs because we assume that you can perform more than 20 reps with those weights. It should also be understood that although we have expressed weights in terms of pounds (lbs), you can just as easily express your weights in terms of kilograms (kg), so long as you use the same units throughout.
Once the graph has been set up, it’s time to plot your RMs on the graph. Suppose your 8RM is 160 lbs. This is your first data value. To plot this data value on the graph, draw a dashed line from the 8 Reps value on the Reps axis all the way up through the graph. Be sure that this line is parallel to the Weight axis. Next, draw a second dashed line from the value 160 on the Weight axis all the way across the graph. This second dashed line should be parallel to the Reps axis. Notice that the two dashed lines intersect. The point where the two lines intersect is your 8RM, so draw a small dot at that point. The graph should now look like this:
Suppose your next data value is a 13RM of 140 lbs. The procedure for plotting this RM on the graph is the same as for the 8RM. Begin by drawing a vertical dashed line which starts at the 13 Reps value on the Reps axis and goes all the way up through the graph. The second dashed line is horizontal and starts at the value 140 on the Weight axis and goes all the way across the graph. Where these two lines intersect each other is your 13RM. Draw a small dot where the two lines intersect. The graph should now look like this:
As you can see, the graph now contains two distinct RM values. It should be noted that we could plot more RM values to make things even more accurate. Of course, doing so would make things a bit more complex and thus goes beyond the scope of this introductory exercise.
Once you have two data points plotted on the graph, you’re ready to draw a “best-fit” line through the points. This line is called a “best-fit” line because if you were using more than two data points, there’s a good chance that a straight line would not pass through all the points. In that case, you’d have to draw the line so that it was as close as possible to all of the points. Hence the name “best-fit” line. In our present example, however, we are dealing with only two data points; our straight line is guaranteed to pass through both points. Line up a ruler or other straight-edge so that it’s aligned with both data points and then draw the best-fit line so that it passes through both points and also crosses over the Weight axis.
The graph should then look like this:
Notice that the best-fit line passes over the vertical Weight axis. It is important to make sure your best-fit line crosses the Weight axis as will become more apparent below.
- Dan Collins