Determine Your One-Rep Max (1RM)

"Oh, yeah?! Well how much can you lift?"

"I don't know, how much can you lift?"

"I bet I can lift more than you."

"Bet you can't."

"Bet I can."

Ever get caught in this type of conversation? You THINK you might be able to lift more than your challenger, but if you're being honest with yourself, you really have no idea. And you certainly don't want to get hurt proving a silly point that means nothing in the grand scheme of things, but you really do want to prove that point only because you might be able to. This conversation ever happen to you?!

If you know your one-rep max (1RM)—proving your point might be within reach. But this isn't really why we determine one-rep max. Your 1RM, otherwise known as the most you can lift during one repetition of any given exercise, is a useful guideline when it comes to building strength or developing endurance.  This number helps you decide just how much you should be lifting.

You've heard the theories:
• More weight and less reps helps build muscle strength.
• Less weight and more reps helps build muscle endurance.

They're not bad theories by any means, and honestly, they're an acceptable way to approach strength training. But we can get a little more specific if we involve some numbers. Mainly, your one-rep max. The more specifically you choose weights from workout to workout, the easier it is to achieve your goals.
 I know, numbers.
Hate them, too.
Don't despair...

There are a number of scientific and mathematical ways to determine your one-rep max, but I think the easiest way to go about it is to simply grab a friend (or a personal trainer) and test yourself.

Let's speak in terms of a single-arm bicep curl, just so we're all on the same page.

To test your one-rep max...really, this is not that hard...you'd simply pick a weight and attempt to curl it. What weight to pick? I'd go with something five pounds heavier than you'd use in your normal set of 12, 15 or XX repetitions. After you curl the weight once, determine whether or not you think you might be able to do more. If you think you just might, let the arm rest (this is important) (maybe do some leg exercises) before you test the bicep again, choosing the next weight up.

Keep your spotter (friend, trainer) close by as you continue in this way. You'll eventually get to a point where you can't complete the single repetition without assistance, at which point you'll know that the previous weight is your one-rep max.

Once you know your one-rep max, you can apply it to the previous theories.
A recent issue of Oxygen states it best:
• "When trying to build strength...four to seven sets of up to five reps at 80 to 90 percent of your 1RM."
• "If you are looking to train for endurance...aim for two to four sets of about 15 reps at 40 to 60 percent."

Based on these updates to the commonly used theories, you just might find that you're not lifting enough. Of course, only your body can really tell you whether that's true. Don't let any theory, chart, calculation or whathaveyou tell determine what your comfort level is. If something doesn't feel right, it probably isn't.

Question: Do you train according to your one-rep max?