The one-rep max (1RM) has been around since the second caveman picked up a rock that was five pounds heavier than the first caveman’s rock. Testing the limits of your strength is a primal urge, if not always a practical one. Unless you are a competitive powerlifter, performing a maximal effort for one repetition has very little value for most people. That’s because a 1RM is a test of strength, it’s not a way to train for strength. Spending your hours in the gym improving your 10RM will do more strength and physique than constantly testing your max. However, knowing your 1RM for various lifts can be incredibly valuable.
An accurate 1RM is more than just a metric by which to measure yourself against other alpha males. Some of the most successful modern strength programs (Westside Barbell, 5/3/1, 5×5) are percentage-based systems that work with submaximal loads based on your 1RM. So while you might not be stepping up for that single blood vessel–rupturing squat, you need to know your 1RM so you can do 10 reps at 60 percent, five reps at 80 percent or whatever your program demands. That 1RM number is like a star by which you will chart your course.
Finding Your 1RM
Figuring out your 1RM the old-fashioned way is the most accurate method, but it has its downsides: Your risk of injury increases, a certain lift might demand a spotter, and the toll it takes on your joints, muscles and nervous system will affect the quality of your training that day. Fortunately, there are other ways of calculating your 1RM.
Method One: Take 80 percent of your estimated 1RM and perform as many reps as possible. Then plug those numbers (weight and reps) into this formula to get your estimated 1RM:
Weight x Reps x .0333 + Weight = Estimated 1RM
Method Two: The National Strength and Conditioning Association developed a chart to find a 1RM that is specific to the three main lifts. Simply multiply the reps by the corresponding coefficient. For instance, if you know that you can bench 225 pounds for a maximum of six reps, then you would calculate:
225 x 1.18 = 265 pounds
A Few Things About Using 1RMs
If You’re a Beginner, Don’t Worry About 1RMs: If you have been lifting seriously for less than a year, forget about 1RMs. You don’t have the neuromuscular connection, the ability to recruit muscle fibers or even the joint integrity to safely find a number that is viable for training purposes.
Be Reasonable: It is one thing to add 40 pounds to your 1RM when you are trading stories over a few beers, but do not embellish your 1RM number to yourself when you are in the gym. The 1RM you are working off should be a number you can do right now. It is not a number that is rounded up, or one that you did two years ago before your shoulder surgery. Check your ego and accept reality. A realistic number will keep you off the injured list and steadily progressing.
Use 1RMs Only for Specific Exercises: Use a percentage-based system only for major compound lifts and their variations, such as the bench press, squat, deadlift, overhead press and cleans. Never attempt a maximal effort on single-joint exercises (hamstring curls, skullcrushers,) or lifts that put you in a precarious position such as good mornings.