Individual Load-velocity Relationships Research Articles

Load–velocity profiling in the military press exercise: Effects of gender and training

This study aimed (1) to analyze the accuracy of mean propulsive velocity to predict the percentage of the 1-repetition maximum in the seated military press exercise and (2) to test the effect of gender and of a resistance training program on the load–velocity profile. The load–velocity relationships of 26 men and 13 women were evaluated by means of an incremental loading test up to the individual 1-repetition maximum. Additionally, the load–velocity relationships of 24 of those 26 men were measured again after a six-week resistance training program. Individual load–velocity relationships had very high coefficients of determination and low standard errors of the estimate (R2 = 0.987; standard error of the estimate = 0.04 m/s). Differences higher than 10% between the individual and the general load–velocity profiles as well as a high between-participants’ variability for the mean propulsive velocity attained at each 1-repetition maximum (coefficient of variation = 12.9–24.6%) were identified. The load–velocity profiles proved to be affected by both the gender (higher mean propulsive velocity at each %1-repetition maximum for men) and the resistance training program (lower mean propulsive velocity at each %1-repetition maximum after training). Taken together, these results speak in favor of creating individual profiles instead of using general equations when using the load–velocity relationship to estimate relative load.

Validity and Reliability of the PUSH Wearable Device to Measure Movement Velocity During the Back Squat Exercise.

Balsalobre-Fernández, C, Kuzdub, M, Poveda-Ortiz, P, and Campo-Vecino, Jd. Validity and reliability of the PUSH wearable device to measure movement velocity during the back squat exercise. J Strength Cond Res 30(7): 1968-1974, 2016-The purpose of this study was to analyze the validity and reliability of a wearable device to measure movement velocity during the back squat exercise. To do this, 10 recreationally active healthy men (age = 23.4 ± 5.2 years; back squat 1 repetition maximum [1RM] = 83 ± 8.2 kg) performed 3 repetitions of the back squat exercise with 5 different loads ranging from 25 to 85% 1RM on a Smith Machine. Movement velocity for each of the total 150 repetitions was simultaneously recorded using the T-Force linear transducer (LT) and the PUSH wearable band. Results showed a high correlation between the LT and the wearable device mean (r = 0.85; standard error of estimate [SEE] = 0.08 m·s) and peak velocity (r = 0.91, SEE = 0.1 m·s). Moreover, there was a very high agreement between these 2 devices for the measurement of mean (intraclass correlation coefficient [ICC] = 0.907) and peak velocity (ICC = 0.944), although a systematic bias between devices was observed (PUSH peak velocity being -0.07 ± 0.1 m·s lower, p ≤ 0.05). When measuring the 3 repetitions with each load, both devices displayed almost equal reliability (Test-retest reliability: LT [r = 0.98], PUSH [r = 0.956]; ICC: LT [ICC = 0.989], PUSH [ICC = 0.981]; coefficient of variation [CV]: LT [CV = 4.2%], PUSH [CV = 5.0%]). Finally, individual load-velocity relationships measured with both the LT (R = 0.96) and the PUSH wearable device (R = 0.94) showed similar, very high coefficients of determination. In conclusion, these results support the use of an affordable wearable device to track velocity during back squat training. Wearable devices, such as the one in this study, could have valuable practical applications for strength and conditioning coaches.

Reliability Analysis of Traditional and Ballistic Bench Press Exercises at Different Loads.

The purpose of this study was to determine test–retest reliability for peak barbell velocity (Vpeak) during the bench press (BP) and bench press throw (BPT) exercises for loads corresponding to 20–70% of one-repetition maximum (1RM). Thirty physically active collegiate men conducted four evaluations after a preliminary BP 1RM determination (1RM·bw-1 = 1.02 ± 0.16 kg·kg-1). In counterbalanced order, participants performed two sessions of the BP in one week and two sessions of the BPT in another week. Recovery time between sessions within the same week was 48 hours and recovery time between sessions of different weeks was 120 hours. On each day of evaluation the individual load-velocity relationship at each tenth percentile (20–70% of 1RM) in a Smith machine for the BP or BPT was determined. Participants performed three attempts per load, but only the best repetition (highest Vpeak), registered by a linear position transducer, was analysed. The BPT resulted in a significantly lower coefficient of variation (CV) for the whole load–velocity relationship, compared to the BP (2.48% vs. 3.22%; p = 0.040). Test–retest intraclass correlation coefficients (ICCs) ranged from r = 0.94–0.85 for the BPT and r = 0.91–0.71 for the BP (p < 0.001). The reduction in the biological within-subject variation in BPT exercise could be promoted by the braking phase that obligatorily occurs during a BP executed with light or moderate loads. Therefore, we recommend the BPT exercise for a most accurate assessment of upper-body velocity.