How to estimate one rep max?

To estimate your one-repetition maximum (one-rep max), which is the maximum amount of weight you can lift for one repetition of an exercise, you can use several methods without actually lifting your maximal load.

Here are a couple of methods mentioned by experts on the Huberman Lab podcast:

1. Conversion Charts: Using a known weight and the number of repetitions you can perform, you can estimate your one-rep max using online conversion charts. For example, if you can do 75 pounds eight times on your bench press, this can be converted into an estimated one-rep max using online tools or charts 1.

2. Repetition Conversion Equations: Choose a weight close to what you believe is your maximum and complete as many repetitions as you can, ideally keeping it under five reps for better accuracy. Input this data into an online one-rep max estimator, which will provide you with an estimated one-rep max 2.

Both of these methods allow you to estimate your one-rep max safely without having to perform a true one-rep max lift, reducing the risk of injury and the need for intense exertion.