Calculate Your 1RM
💪 Recommended Strength Equipment
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📚 Understanding 1RM
What is 1RM?
Your one-rep max (1RM) is the maximum amount of weight you can lift for a single repetition with proper form. It's a crucial metric for:
- 🎯 Strength Assessment: Measuring your current strength levels
- 📈 Progress Tracking: Monitoring strength gains over time
- 📋 Program Design: Calculating training percentages
- 🏆 Competition Prep: Setting realistic goals
Training Zones Based on 1RM
💪 Strength Zone
85-100% 1RM
1-5 reps per set
Builds maximum strength and neural adaptations
🔥 Hypertrophy Zone
65-85% 1RM
6-12 reps per set
Optimal for muscle growth and size
⚡ Endurance Zone
40-65% 1RM
15+ reps per set
Improves muscular endurance and work capacity
1RM Formulas Explained
| Formula | Best For | Accuracy Range | Notes |
|---|---|---|---|
| Epley | General use | 1-10 reps | Most widely used, simple formula |
| Brzycki | Low reps | 1-5 reps | Very accurate for singles and doubles |
| Lander | All-around | 1-15 reps | Good balance across rep ranges |
| Lombardi | Higher reps | 6-15 reps | More accurate for endurance sets |
⚠️ Safety First
- Always warm up properly before attempting heavy lifts
- Use a spotter when testing actual 1RM
- Never sacrifice form for heavier weight
- Rest 3-5 minutes between heavy attempts
- Stop if form breaks down
✅ Testing Protocol
- Set 1: 10 reps @ 50% estimated 1RM
- Set 2: 5 reps @ 70% estimated 1RM
- Set 3: 3 reps @ 80% estimated 1RM
- Set 4: 1 rep @ 90% estimated 1RM
- Set 5: 1 rep @ 95-100% estimated 1RM
- Set 6: 1 rep @ 102-105% (if previous was easy)
❓ Frequently Asked Questions
How accurate are 1RM calculations?
1RM calculations are typically accurate within ±5% when using weights for 2-10 reps. Accuracy decreases with higher rep ranges. Individual factors like training experience and muscle fiber type can affect results.
Which formula should I use?
For most people, the Epley formula works well. If you're using very low reps (1-3), try Brzycki. For higher reps (10+), Lombardi may be more accurate. Test different formulas to see which matches your actual performance.
How often should I test my 1RM?
Testing true 1RM is taxing. Most lifters test every 12-16 weeks. Use calculated 1RM from your regular training sets more frequently to track progress without the stress of max attempts.
Why is my actual 1RM different from calculated?
Several factors can cause differences: technique under heavy loads, mental preparation, muscle fiber composition, and training specificity. Some lifters are better at singles, others at reps.