How One-Rep Max (1RM) Can Enhance Your Training
Strength training can increase muscle mass, improve body composition, increase flexibility, and reduce risk of injury. It not only benefits your fitness, but it also makes you more capable and resilient in your everyday life.
If you’ve been doing this style of training for a while and established a baseline strength in each of the three key lifts of strength training — the squat, deadlift and bench press — you're ready to take your training to the next level. You can progress by using your one-rep max (also known as 1RM or one-repetition maximum) to determine the weight to use for each exercise.
My BUILD program is designed to increase overall strength; by using heavy weights and lower reps to build strength, and higher reps of smaller weights to increase muscle definition. Calculating your 1RM is a way to determine the exact weight you should use for these exercises, which will ensure you’re getting the best results from your training.
What is 1RM?
1RM is the maximum weight you can lift if you only have to do one repetition of an exercise.
It's considered the “gold standard” test of strength. When you lift your 1RM weight, you shouldn't be able to complete a second repetition. The idea is that you give everything you have in that first rep — that's where the name comes from.
Why should I use 1RM in my training?
Knowing your 1RM enables you to choose the correct weight for each exercise, ensuring that you maximise your training benefits and build strength systematically.
When you train at a specific percentage of your 1RM, as recommended in BUILD, my powerbuilding program available in the Sweat app, you can follow a scientifically proven training program to achieve your fitness goals.
Using your 1RM, combined with other training techniques such as variable resistance training, can also help you to overcome a training plateau.
It’s a tool that any woman can use to strategically increase strength — it's not just for bodybuilders and powerlifters.
How is it different to RPE?
RPE and 1RM are both important and useful measures of training intensity.
Rate of perceived exertion (RPE) is subjective rating on how strenuous a particular exercise feels. Your RPE can fluctuate based on how you're feeling, whether you've eaten enough or slept well, stress from work or life, and your total training load for the week.
1RM is an objective measure of your training ability. It represents your total maximum strength for a given lift, under ideal conditions. You may not be able to repeat your 1RM every day, especially when you have had a hard training week or poor sleep.
How do you calculate your 1RM?
You can calculate your 1RM using this formula:
Weight x reps x 0.0333 + weight = estimated 1RM
For example, if you can usually bench 60kg for 6 reps, your 1RM calculation will look like this:
60 x 6 x 0.0333 + 60 = 71.988. Round it up to 72kg, and you have your estimated 1RM.
How do you use 1RM in a workout?
Your 1RM is used to determine how heavy your weights should be in your workouts. Usually, this will be a percentage of your 1RM.
When you first start strength training, you should choose a weight that you can use to complete 10-12 repetitions of an exercise — the last few reps should challenge you.
As you gain strength, you can increase the weight you lift, and decrease the number of repetitions. You'll use your 1RM to determine the amount to lift that will effectively increase your overall muscle strength.
When you use the BUILD program on the Sweat app, you'll use your five-rep max to calculate your 1RM. This is a safer way to test your absolute strength, and it means that you can complete the test at the gym even if you don't have someone there to spot you.
When doing a 1RM or five-rep max test, remember that form comes first. Your 1RM is the lift you can complete one repetition of with correct technique — this protects you from injury and ensures that you gain strength in a balanced way.
Here’s an example of how you might use your 1RM in your weights training:
To improve your endurance, use a weight that’s 70% of your 1RM for sets of 12-20 reps.
Move up to 80% of 1RM
To stress your muscle fibres, use a weight that’s 80% of your 1RM for sets of 7-12 reps.
Increase to 90% of 1RM
To teach your muscles power and speed, use a weight that’s 90% of your 1RM for 3-4 sets of 3-4 reps. Make sure you take enough rest and recovery time in between each set.
Increase to 95% of 1RM
To push past your limits and focus on strength, use a weight that’s 95% of your 1RM for sets of just 1-3 reps. This will feel heavy, so make sure you have a spotter to keep you safe during each lift.
Do any of the Sweat programs use 1RM?
Yes! BUILD — my powerlifting and bodybuilding program — is all about improving your 1RM. You complete a small assessment in Week 1 of BUILD to determine your 1RM for three main lifts: the deadlift, bench press, and squat.
You then train with weights at a specific percentage of your 1RM, practising the correct technique and form to help you slowly increase your 1RM over time.
How often should you test your 1RM?
In BUILD, you’ll test your 1RM every 12 weeks, but you don't actually need to test it very often.
Many professionals or experienced lifters only test it once or twice a year. This means they can work to a structured program that progressively overloads their muscles and includes plenty of time for rest and recovery.
Is lifting heavy weights really better than lifting light weights?
It all depends on what your training goals are. If you want to increase muscle volume, lighter weights are just as effective as heavy weights. However, if you want to increase muscle strength, lifting heavy weights is more effective.
A small 2012 study by McMaster University, Canada, published in the Journal of Applied Physiology, compared the training effects of light weights to heavy weights.
Over a 10 week period, researchers tested the effects of performing leg extensions with either heavy (80% of 1RM) or light (30% of 1RM) weights. The researchers found that both heavy and light loads increased muscle mass equally. But for building strength, the 80% load produced superior results.
How reliable is the 1RM test?
Numerous studies have assessed the reliability of the 1RM test. In 2012, a study by Dongguk University, Korea, examined the reliability of the 1RM test based on muscle group and gender. The researchers concluded that 1RM testing is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender.
In 2009, a small study by Victoria University, Australia, published in the Journal of Sports Science and Medicine, looked into the reliability of the 1RM strength test of untrained men and women aged 18-35 years and concluded it was a reliable method of evaluating the maximal strength in that age group.
1RM is the ultimate key to training smarter
When you follow a structured workout program that applies your 1RM, over time you can gradually increase the total amount that you can lift for each compound exercise. You’ll gain confidence, build strength, and with discipline and consistency, one day you might lift a weight you'd thought was impossible.
As you advance in your knowledge of weight training, you'll discover that there are many ways to increase your strength — variable resistance training is a technique you can use to advance your 1RM and break through a training plateau.
Looking for more workout advice? Check out these workout tips for inspiration.
* Results may vary. Strict adherence to the nutrition and exercise guide are required for best results.