Evaluating Velocity-Based Approaches for Predicting One-Repetition Maximum in The Snatch.

Between-sessions reliability was acceptable for actual 1RM, peak velocity at single loads, actual MVT, and optimal MVT in the snatch.

• Fourteen competitive adolescent male weightlifters participated (age: 15.9 ± 0.9 years; training experience: 5.1 ± 0.9 years).
• Intraclass correlation coefficients ranged from 0.76 to 0.90 across measures.
• Coefficient of variation ranged from 1.82% to 3.31% across measures.
• Measures assessed included actual 1RM, PV at 50%, 70%, 80%, and 90% of 1RM, actual MVT, and optimal MVT.

The actual MVT, optimal MVT, and individual %1RM-PV relationship using 80% and 90% 1RM yielded acceptable and lower absolute errors compared to methods using 50% and 70% 1RM.

• Absolute errors for actual MVT, optimal MVT, and individual %1RM-PV at 80% and 90% 1RM ranged from 2.6 to 4.1 kg.
• Absolute errors for individual %1RM-PV relationship using 50% and 70% 1RM were notably higher, ranging from 6.2 to 9.9 kg.
• All methods that showed lower absolute errors also exhibited proportional bias (p = 0.002–0.018).
• Heteroscedasticity was observed for the actual MVT and 90% 1RM methods (p = 0.022–0.026).

The load-peak velocity relationship combined with minimal velocity threshold methods provided better 1RM predictions than single-load methods at lighter intensities.

• 1RM in the second session was predicted using the load-PV relationship derived from four loads (50%, 70%, 80%, 90% 1RM) combined with either actual or optimal MVT obtained in the first session.
• The actual and optimal MVT methods produced absolute errors of 2.6–4.1 kg.
• Single-load methods at 50% and 70% 1RM produced substantially larger errors of 6.2–9.9 kg.
• Peak velocity was recorded using a linear position transducer.

Proportional bias was present in all methods that demonstrated acceptable prediction accuracy, indicating that prediction error varies systematically with the magnitude of the actual 1RM.

• Proportional bias was observed for actual MVT, optimal MVT, and individual %1RM-PV methods at 80% and 90% 1RM (p = 0.002–0.018).
• Heteroscedasticity was specifically observed for the actual MVT and 90% 1RM methods (p = 0.022–0.026).
• The presence of proportional bias and heteroscedasticity means these methods may not provide accurate predictions for all athletes.
• These findings suggest coaches should use velocity-based prediction with caution in individual athlete contexts.

The study protocol involved incremental loading tests across two sessions with attempts at standardized percentages of recent best snatch performance.

• Participants performed attempts at 50%, 70%, 80%, and 90% of their best snatch record from the past 30 days, followed by load increases until reaching actual 1RM.
• Two testing sessions were completed to assess between-session reliability.
• The second session 1RM was predicted using data from the first session.
• Both load-velocity relationship methods and single-load methods were evaluated.

Velocity-based methods using warm-up set data may serve as a complementary tool for opener selection in competitive weightlifting but cannot replace traditional coaching judgment.

• The authors concluded that recording PV during warm-up sets prior to competition may serve as a 'complementary variable to support and refine opener selection.'
• The approach was not recommended as a standalone prediction tool due to proportional bias and heteroscedasticity.
• The study population was competitive adolescent male weightlifters, which may limit generalizability.
• The authors specifically noted the approach 'may not provide accurate snatch performance predictions for all athletes.'