1RM (1 Rep Max) Calculation

nrg500

1RM or 1 Rep Max is the maximum amount of weight you can lift for 1 repetition in a specific exercise


Knowing your 1RM helps in measuring your progress

Example:

Last week, in the bench press, you were able to lift 200 lbs for 6 reps. Then, for this week, you were able to lift 220 lbs for 4 reps. You can calculate your 1RM to measure your progress

Using Brzycki Formula, here are the 1RM equivalents

200 lbs x 6 reps = 232 lbs x 1 rep

220 lbs x 4 reps = 240 lbs x 1 rep

You increased your 1RM by 3.45%


== == == ==
Brzycki Formula
== == == ==

1RM = w / (1.0278 - 0.0278 * r)

w is the amount of weight lifted
r is the number of repetitions


== == == ==
Epley Formula
== == == ==

1RM = w * [(r/30) + 1]

w is the amount of weight lifted
r is the number of repetitions


== == == ==
Lander Formula
== == == ==

1RM = w / (1.013 - 0.0267123 * r)

w is the amount of weight lifted
r is the number of repetitions



Take note that 1RM formulas just give estimates and not absolute values. In the example above, it is not guaranteed that you will be able to lift 232 lbs for 1 rep if you can lift 200 lbs for 6 reps. You may be able to lift higher or lower than 232 lbs. Also, the formulas are only usable to a rep range of 1 to 10. The accuracy of the formulas degrades when you go beyond 10 reps. Lastly, each of the formulas will give different values. The accuracy of each will vary from person to person. Whatever formula you choose, just use it as a guide only to measure your progress.

To make computations easier, you can use MS Excel or any other spreadsheet program to automatically calculate the values for every workout session

(To admin/moderators, I hope you can make this topic pinned if you find it helpful. Thanks)



SOURCE http://www.weightrainer.net/training/coefficients.html

asggelo

an addition to this thread.

1RM TESTING PROTOCOL

1. Instruct the athlete to warm up with a light resistance that easily allows 5 to 10
repetitions.
2. Provide a 1-minute rest period.
3. Estimate a warm-up load that will allow the athlete to complete three to five repetitions
by adding
10 to 20 pounds (4-9 kg) or 5% to 10% for upper body exercise or °
30 to 40 pounds (14-18 kg) or 10% to 20% for lower body exercise. °
4. Provide a 2-minute rest period.
5. Estimate a conservative, near-maximal load that will allow the athlete to complete two to
three repetitions by adding
10 to 20 pounds (4-9 kg) or 5% to 10% for upper body exercise or °
30 to 40 pounds (14-18 kg) or 10% to 20% for lower body exercise. °
6. Provide a 2- to 4-minute rest period.
7. Make a load increase:
10 to 20 pounds (4-9 kg) or 5% to 10% for upper body exercise or °
30 to 40 pounds (14-18 kg) or 10% to 20% for lower body exercise. °
8. Instruct the athlete to attempt a 1RM.
9. If the athlete was successful, provide a 2- to 4-minute rest period and go back to step 7.
If the athlete failed, provide a 2- to 4-minute rest period, then decrease the load by subtracting
5 to 10 pounds (2-4 kg) or 2.5% to 5% for upper body exercise or °
15 to 20 pounds (7-9 kg) or 5% to 10% for lower body exercise °
AND then go back to step 8.
Continue increasing or decreasing the load until the athlete can complete one repetition
with proper exercise technique. Ideally, the athlete’s 1RM will be measured within three to five
testing sets.

Figure 15.1 A 1RM testing protocol.
Reprinted, by permission, from Earle, 2006 (23)

SOURCE : Page 396; Essentials of Strength Training and Conditioning 3rd Ed