BLUF
A recent study published in the Journal of Strength and Conditioning Research examined a more efficient method for estimating the one-repetition maximum (1RM) in the free-weight back squat. The researchers compared nine different 1RM estimation approaches based on velocity recordings, concluding that the 2-Point Method combined with the Optimal Minimal Velocity Threshold (MVT) provided the most accurate predictions.
Key Findings
- Comparison of 1RM Estimation Methods:
The study evaluated three types of Load-Velocity Relationship (LVR) models:- Multiple-Point Method – Uses data from six different loads (40-90% of 1RM).
- Extracted 2-Point Method – Uses only the lightest and heaviest loads from the Multiple-Point test.
- 2-Point Method – Uses data from just two loads (40% and 90% of 1RM).
- Three MVTs were analyzed:
- Actual MVT – The velocity recorded at the actual 1RM.
- General MVT – A fixed velocity value of 0.30 m·s⁻¹.
- Optimal MVT – The velocity that minimizes the difference between actual and predicted 1RMs.
- Accuracy of Predictions:
- The Optimal MVT was significantly more accurate, with raw errors ≤0.8 kg and absolute errors ≤4.0%.
- The 2-Point Method combined with the Optimal MVT was just as accurate as the more complex Multiple-Point and Extracted 2-Point methods.
- While the LVR model choice had no significant effect on prediction accuracy (p = 0.079), the type of MVT used did (p < 0.001).
- Practical Advantages of the 2-Point Method:
- Efficiency: Requires only two sets at 40% and 90% of 1RM, reducing testing time and fatigue compared to traditional multi-load tests.
- Accuracy: Produces a highly reliable 1RM estimate, as shown by significantly higher mean velocity (MV) at 90% 1RM compared to the Multiple-Point Method.
- Feasibility: Provides a simple, time-efficient alternative for coaches and athletes in applied settings.
Methodology
- Participants: 39 resistance-trained male subjects (ages 18–24).
- Procedure: Subjects completed two sessions with six loads (40-90% of 1RM) and two sessions with only two loads (40% and 90% of 1RM), followed by actual 1RM attempts. The testing order was counterbalanced to minimize bias.
- Data Collection: Mean velocity was recorded using a GymAware PowerTool, and LVRs were modeled using individual linear regression.
- Statistical Analysis: Absolute errors, paired t-tests, effect sizes (Cohen’s d), and Bland–Altman plots were used to assess prediction accuracy.
Implications for Training Performance
- The 2-Point Method with Optimal MVT is a practical and accurate solution for rapid 1RM estimation in the free-weight back squat.
- It minimizes testing fatigue and can be easily integrated into regular training sessions.
- A constant Optimal MVT of 0.40 m·s⁻¹ may serve as a practical alternative to individualized MVT testing, simplifying implementation.
Limitations and Future Research
- The study did not examine long-term variability of the Optimal MVT or its application across different populations (e.g., females, elite athletes).
- Future research should validate whether the constant Optimal MVT (0.40 m·s⁻¹) provides consistent accuracyacross different training conditions and populations.
- Additional studies should assess how factors like technique, motivation, and external loading strategies affect the Optimal MVT’s reliability.
Conclusion
This study demonstrates that the 2-Point Method combined with the Optimal MVT is an efficient and accurate way to estimate the 1RM for the free-weight back squat. Its practical application makes it a valuable tool for strength and conditioning professionals seeking to optimize performance assessments while minimizing fatigue and time investment.
Bibliography
Chen, Z., Xiao, F., Mao, Y., Zhang, X., & García-Ramos, A. (2024). An efficient and accurate approach for estimating the free-weight back squat 1-repetition maximum based on the 2-point method and optimal minimal velocity threshold.Journal of Strength and Conditioning Research. DOI: 10.1519/JSC.0000000000005040.