Estimating Training Loads for a Given Number of Repetitions

Manipulating the number of sets, repetitions, and tempo in a strength-training program is essential for creating new stimulus and driving continual progress. However, when changing the number of repetitions, it can be hard to figure out what weight to use.

In this blog, a simple method of estimating the maximum weight you can lift for a given number of repetitions is presented.

In the Strength and Conditioning world, there is a well established chart that predicts the amount of weight you can lift, for a given number of reps, relative to your 1 Rep Max load. NSCA (National Strength and Conditioning Association), for example, has a chart which you can view HERE.

By definition, the maximum weight you can lift for one repetition, your 1 Rep Max or 1RM, is 100% of your 1RM load.

For most people, testing your one repetition maximum weight for any exercise can be dangerous for a number of reasons. Your form must be perfect and, even if it is, the risk of injury is still high. Only very advanced lifters should attempt 1RM weights and it shouldn’t be done very often.

The key information from the NSCA chart is summarized in the below table, showing how heavy your load should be for a given number of repetitions compared to your 1 Rep Max load.

• Max Reps (RM) | % of 1RM Load

• 1 → 100%

• 2 → 95%

• 3 → 93%

• 4 → 90%

• 5 → 87%

• 6 → 85%

• 7 → 83%

• 8 → 80%

• 9 → 77%

• 10 → 75%

• 12 → 70%

To illustrate how useful this chart is, let’s walk through an example. If you can do a barbell squat at 135 Ibs for 12 reps, we know from the chart that weight is approximately 70% of your one repetition weight.

So if you changed your program to 8 reps, we can calculate what your weight should be based on the above table as follows:

(1/0.7)x135 = 192.857 Ibs (this is your estimated 1 Rep Max weight for the barbell back squat)

Since 8 reps is at 80% of 1RM, your estimated 8 rep max weight should be as follows:

0.8x192.857 = 154.286 Ibs

If we round that up to the nearest weight that is possible and available in most gyms, that would be 155 Ibs.

Note that this is just an estimate but it helps to save time when you are trying to figure out what weight to use for a given number of reps.

Remember to always warm up before your working sets. The more weight you lift, the more warm-up sets you will need to perform.As a minimum you should do 2 warm-up sets.

If you are doing 8 reps for the first time on the barbell back squat, and you have estimated the weight to be approximately 155 Ibs, perform your first warm-up weight at 50%, which is 77.5 Ibs.

A second warm-up should then be done at approximately 75% of your working set weight, which is 115 Ibs. Assuming everything feels good, you can then attempt 8 reps at 155 Ibs.