One rep maximum

One rep maximum (one repetition maximum or 1RM) in weight training is the maximum amount of weight one can lift in a single repetition for a given exercise. One rep maxima 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 rep maxima can also be used as an upper limit, in order to determine the desired "load" for an exercise (as a percentage of the 1RM).

Calculating 1RM

Various weight training protocols call for lifting some percentage of the lifter's 1RM. However, many consider the risk of injury when attempting a 1RM to be equal to or higher than when performing multiple rep sets. Therefore, there have been various proposals for ways to calculate an approximation of the 1RM.

There are two common formulas used to calculate your one rep maximum. [ [http://www.build-muscle-and-burn-fat.com/one-rep-max.html"See How Easily You Can Calculate Your One Rep Max."] ] If $r$ is the number of repetitions performed and $w$ is the amount of weight used, then

Formula 1

$1RM\; =\; left\; [\; left\; (\; frac\{r\}\{30\}\; ight\; )\; +\; 1\; ight\; ]\; imes\; w$

Formula 2

This version of the one rep maximum calculation is often referred to as the Brzycki Formula after its creator, Matt Brzycki. [cite book | author=Brzycki, Matt | title=A Practical Approach To Strength Training | publisher=McGraw-Hill | year=1998 | id=ISBN 1-570-28018-5] and can be written either in terms of integers or decimal approximation:

$1RM\; =\; w\; imes\; frac\; \{36\}\{\; left\; (\; 37\; -\; r\; ight\; )\; \}\; =\; frac\{w\}\{\; left\; [\; frac\{37\}\{36\}\; -\; left\; (\; frac\{1\}\{36\}\; imes\; r\; ight\; )\; ight\; ]\; \}\; approx\; frac\{w\}\{\; left\; [\; 1.0278\; -\; left\; (\; 0.0278\; imes\; r\; ight\; )\; ight\; ]\; \}$

Both formula 1 and 2 return similar results for 10 repetitions. However, for less than 10 reps, formula 1 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 formula 1 would estimate a one rep maximum of approximately 120 pounds, while formula 2 would both return an estimate of approximately 116 pounds.

These types of calculations may not always produce accurate results, but can be used as starting point. The weight can then be changed as needed to perform the number of reps called for by the training protocol.

Several more complex formulae have been proposed which use different coefficients for different rep numbers and sometimes even for different exercises.

One rep maximum calculators are used to "predict" a one rep maximum lift. The degree of accuracy can vary largely depending on the weight training experience and muscular composition (genetic) of the athlete. Also, most one rep maximum calculators are design for seasoned strength trainers, and those with little experience may find their actual one rep maximum is much lower because their nervous system cannot handle the stress of a high weight. This should not be performed without a spotter for reasons of safety.

ee also

* Weight Training

External links

External links

* [http://www.runningdeersoftware.com/products/musclecalc-1repmax.htm One-Rep Max Estimator with rep ranges, percentages and graphing]
* [http://www.bodybuilding-supplement-guide.com/1-rep-max-bench-press-calculator.html 1 rep max bench press calculator]
* [http://www.exrx.net/Calculators/OneRepMax.html ExRx.net: One-rep max calculator]
* [http://www.timinvermont.com/fitness/orm.htm A 1RM calculator and explanation of several different calculation methods.]
* [http://www.personaltrainingprograms.com/test/maxtest_eng.asp Free: One Repetition Maximum Calculator.]
* [http://www.club150kg-dc.fr/Goodies/Contenu/PECSonline_Frameset(uk).htm 1RepMax Calculator providing 24# results]
* [http://marunde-muscle.com/maxcalculator.html one rep max calculator in Jess Marunde's web]