Go big or go home — sounds simple enough, right? But there’s an art to finding that one-rep max (read: the heaviest weight you can move once on a given exercise) — and safety is key. Some use math; others, brute force. Either way, it’s important to prepare the body and the brain for the all-out effort (and make sure spotters are prepped and ready!). Read on to find out just how strong you are — safely.

Heavy Stuff — The Need-to-Know

Photo by Jordan Shakeshaft

There are two reasons to test a one-rep max. First, the one-rep max is a classic test of strengthOne-repetition maximum strength test represents a valid means to assess leg strength in vivo in humans; Verdijk LB, van Loon L, Meijer K, et al. Department of Human Movement Sciences, Maastricht University, Maastricht, Netherlands. Journal of Sports Science, 2009 Jan 1;27(1):59-68.. Having logged day after day in the gym, it’s time to see what those shoulders and thighs can really do (and knowing that can help set new fitness goals). Secondly, knowing that max is key to certain weight training programs, since they can provide a measurable template for progress and periodization (i.e. varying a training program at regular time intervals to optimize performance).

For instance, a program for muscular hypertrophy (read: landing bigger muscles) might prescribe a shoulder press for five sets of five repetitions at 75 percent of a one-rep max. Without a solid guestimation, even the savviest lifter will be lost. But why use percentages? It’s a very standardized way of adding manageable weight each week — and backing off when need be. So 75 percent becomes 77.5 percent the following week, and so on, until you’re lifting more than ever before (nerds call this progressive overload).

Of course, the occasional lifter or class-goer will probably not need to worry themselves with the numbers as much (although keeping a workout log is great to track progress). And for newbies or those returning to strength training, remember, a one-rep max test isn’t for day one. Some strength coaches, including Dan John, recommend taking at least two months familiarizing the mind and body with the movements before attempting a max effort lift.

As for which exercises are worthy of a one-rep max test, it all depends on the nature of the program (oftentimes they will specify). But the most common movements usually include variations of the squat, deadlift, Olympic lifts (snatch and clean and jerk), overhead press, and bench press. Alright, enough flexing — let’s find out just how strong we really are.

Mad Max — Your Action Plan

Lifters have two avenues to find a one-rep max. But to avoid a wrong turn (or car wreck), first make sure the body is fully recovered from previous workouts since a max lift should be utilizing the extreme upper limit of one’s strength. Also, be sure to properly warm up, (including foam rolling or some other form of myofascial release) to get the muscles primed and ready to work. Finally — and this is key — enlist some able-bodied friends as spotters. (Maximum effort lifts require maximum supervision!)

  • The predicted one-rep max: Mathletes, this one’s for you. First, choose a repetition range (three and five are the most popular). Warm up adequately, working to the heaviest possible weight at this given number of reps with solid form (with upwards of two to three minutes rest between each set). Then, hit the smartphone — or a handy dandy chart — to calculate your predicted one-rep max using an exercise science-approved equationPrediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry; Reynolds JM, Gordon TJ, Robergs RA. Exercise Physiology Laboratories, Exercise Science Program, University of New Mexico, Albuquerque, NM. Journal of Strength and Conditioning Research, 2006 Aug;20(3):584-92.. So if you banged out three bench presses at 225 pounds, type that amount into the formula, and bam! Your expected one-rep max is 238 pounds — ready, set, lift! (Of course, if this number seems seriously out of reach, best to listen to the body and bring it down a notch.)

Which test is best for me? Comfort is key. The true one-rep max test will be more ideal for the experienced weightlifter (since knowing your own strength is key). And while the predicted test is not 100 percent accurate, it does provide an adequate measure of strength for the everyday lifter.

If this seems a little intimidating, there are alternatives to finding a one-rep max and using its percentages. Instead, some experts recommend working up to a heavy weight to rep ratio day-to-day while focusing on proper form. Eric Cressey and Greg Everett provide excellent guidelines on this organic approach at their websites.

And don’t try for a new one-rep max every time you hit the gym. Give muscles plenty of time to recover and strengthen. Different programs call for varied numbers of one-rep max tests in a single day, but it is not often that more than three tests are performed in a single session. Consider performing tests every six to 12 weeks, or as your program deems necessary. And remember: Bigger gains in strength will be made as a beginner than at any other point in a strength training “career.” Don’t be discouraged — getting stronger is a tortoise’s game, not a hare’sInfluence of previous experience on resistance training on reliability of one-repetition maximum test; Ritti-Dias RM, Avelar A, Salvador EP, et al. School of Physical Education, University of Pernambuco, Pernambuco, Brazil. Journal of Strength and Conditioning Research, 2011 May;25(5):1418-22..

Posting a new PR from time to time guarantees a healthy confidence boost, and can help structure goals for the future. So be safe and have fun. Getting stronger is only part of the equation.

Experts’ Takes

This article has been ready and approved by Greatist Experts Kelvin Gary and Joe Vennare. Here’s a little more on what they had to say:

Kelvin Gary: “In addition to proving how tough you are, finding your one-rep max is a great way to gauge how you’re doing with your strength training program. As mentioned, a well thought out program uses weights that are a percentage of your one-rep max at varying rep ranges. Knowing your one-rep max and re-assessing after six to eight weeks is a great way to make sure you’re training at the right intensity.”

Joe Vennare: “The idea behind finding and applying a one-rep max is to measure and track performance. If someone is taking the time find or calculate this number, it only makes sense that they are also taking care to record exercises and weights selected during workouts. Keep it simple with a pad and pen or (nerd alert!) create a spreadsheet and line graph to chart each training session. Either way, the endgame should be the same: become stronger and more muscular by applying the principal of progressive overload (read: over time, increasing the amount of weight used for each exercise). Down the road, retest your one-rep max. If you’re able to move more weight, congratulations, your had work is paying off. If you have not improved or, and it pains me to say this, you have gotten weaker, it’s time to reevaluate your nutrition and training regimens.”

Have you tested your one-rep max before? How did you fare? Tell us in the comments below!