1. What is the ExRx 1RM Equation?

The ExRx (Exercise Prescription) 1RM equation estimates your one-repetition maximum from submaximal lifts. It's a safer alternative to testing your actual 1RM and provides a good estimate for strength training programming.

2. How Does the Calculator Work?

The calculator uses the ExRx 1RM equation:

Where:

• \( weight \) — Weight lifted (lb)
• \( reps \) — Number of repetitions performed
• 0.0333 — Constant coefficient

Explanation: The equation accounts for the relationship between repetitions performed and the percentage of your 1RM.

3. Importance of 1RM Calculation

Details: Knowing your estimated 1RM helps in designing strength training programs, determining appropriate training loads, and tracking strength progress over time.

4. Using the Calculator

Tips: Enter the weight you lifted in pounds and the number of repetitions you performed with that weight. For best results, use a weight you can lift for 2-10 reps.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this 1RM estimation?
A: The ExRx formula provides a good estimate for most people, but accuracy decreases for very high rep ranges (>10 reps).

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.

Q3: How often should I test/estimate my 1RM?
A: Every 4-8 weeks is typical for tracking progress in a strength training program.

Q4: Should beginners use this calculator?
A: Yes, but beginners should focus more on proper form than max strength numbers.

Q5: Are there other 1RM formulas?
A: Yes, other popular formulas include Brzycki, Epley, and Lombardi. Results may vary slightly between formulas.