science

One-repetition maximum

One-repetition maximum is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand One-repetition maximum rather than just read about it. In short: One-repetition maximum (one-rep max or 1RM) in weight training is the maximum amount of weight that a person can possibly lift for one repetition. It may also be considered as the maximum amount of force that can be generated in one maximal contraction.

Key takeaways

One-repetition maximum belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect One-repetition maximum to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of One-repetition maximum from memory before moving on to harder problems.

Reference excerpt

One-repetition maximum (one-rep max or 1RM) in weight training is the maximum amount of weight that a person can possibly lift for one repetition. It may also be considered as the maximum amount of force that can be generated in one maximal contraction.

Usage

One repetition maximum can be used for determining an individual's maximum strength and is the method for determining the winner in events such as powerlifting and weightlifting competitions. One repetition maximum can also be used as an upper limit, in order to determine the desired "load" for an exercise (as a percentage of the 1RM). Weight training protocols often use 1RM when programming to ensure the exerciser reaches resistance overload, especially when the exercise objective is muscular strength, endurance or hypertrophy. By understanding the maximal potential of the muscle, it is possible to reach resistance overload by increasing the number of repetitions for an exercise.

Measuring 1RM Most commonly, 1RM is determined directly using trial and error testing. The participant lifts progressively heavier free weights, resting for several minutes between each attempt, until the maximum weight for which the participant can complete one full repetition is determined. The 1RM then lies between this weight and the next highest attempted weight. This type of assessment is considered the most accurate way to determine 1RM, and is considered safe when performed correctly. However, as adequate rest must be given between attempts, proper 1RM assessment may be very time-consuming if the initial weight is far from the 1RM. Novices may find the procedure intimidating and unnerving, and be reluctant to add weight. There is also a risk of injury if a participant is unfamiliar with the proper form. A spotter can alleviate these concerns.

Estimating 1RM

The 1RM can also be estimated indirectly using repetition testing on submaximal loads, as popularized by the use of 1RM calculators. Although in many cases the estimate is reasonable, in other cases the estimate may vary by 10% or more from the actual 1RM. Using a specialized formula for the specific exercise improves accuracy. The use of anthropometric variables such as gender, age, height, weight, body fat percentage, and girth does not improve accuracy. Also, most formulas are for experienced weightlifters, and novices may find their actual one rep maximum is much lower because their nervous system cannot handle the stress of a high weight. There are many formulas used to estimate 1RM using the submaximal method. In the formulas below, r {\displaystyle r} is the number of repetitions performed and w {\displaystyle w} is the amount of weight used (note that w {\displaystyle w} is a factor of each formula, so the unit of measurement doesn't matter).

Of the formulas, the Epley and the Brzycki formulas are most commonly used. Epley and Brzycki return identical results for 10 repetitions. However, for fewer than 10 reps, Epley returns a slightly higher estimated maximum. For example, if a person can lift 100 pounds on a given exercise for 10 reps, the estimated one rep max would be 133 pounds for both formulae. However, if the person were to complete only 6 reps, then Epley would estimate a one rep maximum of approximately 120 pounds, while Brzycki would return an estimate of approximately 116 pounds. Several more complex formulae have been proposed which use different coefficients for different rep numbers and sometimes even for different exercises. Compared to a formal 1RM test, the submaximal estimation method is safer and quicker. The estimate may not be accurate, but can be used as the starting point for a 1RM test. The formulas can also be used the other way, to calculate what weight is needed for a given repetition maximum, as a percent of the estimated or actual 1RM.

Worked examples

Example 1 — a first encounter with One-repetition maximum

Start with the simplest possible case. Write down what One-repetition maximum claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to One-repetition maximum before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about One-repetition maximum ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of One-repetition maximum

In research: One-repetition maximum appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses One-repetition maximum in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: One-repetition maximum is common in secondary-school and first-year university syllabi. It links to neighbouring topics Weight training, so understanding it makes those chapters shorter.
In everyday life: Look for One-repetition maximum outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study One-repetition maximum in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what One-repetition maximum means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain One-repetition maximum out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is One-repetition maximum in simple terms?

Why does One-repetition maximum matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study One-repetition maximum?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on One-repetition maximum.