Ask an expert
Question

02 Mar 2003

1 repetition maximum
Hi. Please could you give me the formula and explain how to work out the 1RM. Many thanks
Answer 405 views
Expert
FitnessDoc
fitnessdoc

01 Jan 0001

There are a number of equations and methods that are used for this purpose. Not all of them are very reliable, and most of them make many assumptions which can lead to great inaccuracies. The best way of doing this is to actually do the 1-RM test, but this can be impractical, and dangerous if you are not experienced or assisted in the right way. Therefore, the easiest way of calculating your 1-RM is according to the following method:

Reps %1RM
1 100
2 95
3 90
4 88
5 86
6 83
7 80
8 78
9 76
10 75
11 72
12 70


This is how you use the table. Find the number of reps to failure that you can perform with a certain weight. In other words, choose a weight and if you can only do eight reps with a certain weight and could not possibly do another full rep, that is your point of failure. Find the percentage associated with that number of repetitions from the table above.

Now, divide the weight that you can do by that percentage using decimals (83 percent equals .83) and that will give you an approximation of your one repetition maximum. For example, if you can perform 10 reps with 40 kg in the bench press, that means that 40 kg is 75% (0.75) of your one repetition maximum. So you would take 40 divided by .75 and that would equal 53 kg. Remember that this may be inaccurate, and you may in fact have a 1-RM higher or lower than this. However, as a general guideline, it should suffice. You can of course check it by attempting to lift the weight of 53. If you can do it only once, you have your 1-RM. Remember to have someone experienced to spot for you and to help you, or you can be injured doing the 1-RM test. Then, use this value as a marker and track your improvements in strength over the next few weeks and months.

Best wishes
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.
Voting Booth
Have you entered our Health of the Nation survey?
Please select an option Oops! Something went wrong, please try again later.
Results
Yes
34% - 9249 votes
No
66% - 17779 votes
Vote