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1RM Equation:
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The 1RM (One Repetition Maximum) equation estimates the maximum weight a person can lift for one repetition based on their performance with submaximal weights. This is commonly used in strength training to determine training loads without requiring an actual maximal lift attempt.
The calculator uses the Epley formula:
Where:
Explanation: The equation accounts for the relationship between repetitions performed and the percentage of 1RM, providing an estimate without requiring a maximal effort.
Details: Knowing your estimated 1RM helps in designing strength training programs, determining appropriate training loads, and tracking progress over time without the need for frequent maximal testing.
Tips: Enter the weight you lifted and the maximum number of repetitions you could perform with that weight. The weight must be greater than 0, and repetitions should be between 1-20 for accurate results.
Q1: How accurate is this 1RM prediction?
A: The Epley formula is generally accurate within ±5% for most people, though individual variations exist. It's most accurate for 2-10 repetitions.
Q2: Can I use this for any exercise?
A: It works best for compound lifts like bench press, squat, and deadlift. Accuracy may vary for isolation exercises or endurance-focused movements.
Q3: What if I can do more than 10 reps?
A: The formula becomes less accurate above 10 reps. For higher rep ranges, consider using a different formula or performing an actual 1RM test.
Q4: Should I test my actual 1RM?
A: While predictions are useful, occasional actual 1RM testing (with proper warm-up and safety precautions) can validate your estimated numbers.
Q5: How often should I recalculate my 1RM?
A: Recalculate every 4-8 weeks as your strength changes, or whenever you can perform more reps with a given weight than before.