Purpose: An a posteriori multicenter reliability study was conducted to compare the reliability of the outcomes derived from the linear force–velocity (F–V) relationship (F-intercept [F 0], V-intercept [V 0], F–V slope, and maximum power [Pmax]) using a 2-point method based on 2 distant loads with respect to a multiple-point method based on 4 proximal loads and a multiple-point method that considered all 6 tested loads. Method: Data from 63 healthy men derived from 3 studies were analyzed. The F–V relationship obtained from the bench-press-throw exercise was determined in 2 separate sessions using 3 different combinations of loads: 2-point method (20–70% of 1-repetition maximum [1RM]), 4-load multiple-point method (30–40–50–60% of 1RM), and 6-load multiple-point method (20–30–40–50–60–70% of 1RM). Reliability was assessed through the coefficient of variation (CV), whereas a CVratio of 1.15 was deemed as the smallest important ratio. Results: The 2-point method provided the outcomes of the F–V relationship with greater reliability than the 4-load multiple-point method (F 0, 3.58% vs 4.53%, CVratio = 1.27; V 0, 5.58% vs 7.85%, CVratio = 1.41; F–V slope, 8.57% vs 11.99%, CVratio = 1.40; Pmax, 4.33% vs 4.81%, CVratio = 1.11). The reliability of the 6-load multiple-point method was comparable to the 2-point method (F 0, 3.53%, CVratio = 1.01; V 0, 5.32%, CVratio = 1.05; F–V slope, 8.38%, CVratio = 1.02; P 0, 3.74%, CVratio = 1.16). Conclusion:The distance between experimental points is more important for obtaining a reproducible F–V relationship than the number of experimental points; therefore, the 2-point method could be recommended for a quicker assessment of the F–V relationship.
Amador García-Ramos and Slobodan Jaric
Amador García-Ramos, Slobodan Jaric, Paulino Padial and Belén Feriche
This study aimed to (1) evaluate the linearity of the force–velocity relationship, as well as the reliability of maximum force (F 0), maximum velocity (V 0), slope (a), and maximum power (P 0); (2) compare these parameters between the traditional and ballistic bench press (BP); and (3) determine the correlation of F 0 with the directly measured BP 1-repetition maximum (1RM). Thirty-two men randomly performed 2 sessions of traditional BP and 2 sessions of ballistic BP during 2 consecutive weeks. Both the maximum and mean values of force and velocity were recorded when loaded by 20–70% of 1RM. All force–velocity relationships were strongly linear (r > .99). While F 0 and P 0 were highly reliable (ICC: 0.91–0.96, CV: 3.8–5.1%), lower reliability was observed for V 0 and a (ICC: 0.49–0.81, CV: 6.6–11.8%). Trivial differences between exercises were found for F 0 (ES: < 0.2), however the a was higher for the traditional BP (ES: 0.68–0.94), and V 0 (ES: 1.04–1.48) and P 0 (ES: 0.65–0.72) for the ballistic BP. The F 0 strongly correlated with BP 1RM (r: 0.915–0.938). The force–velocity relationship is useful to assess the upper body maximal capabilities to generate force, velocity, and power.
Francisco Luis Pestaña-Melero, G. Gregory Haff, Francisco Javier Rojas, Alejandro Pérez-Castilla and Amador García-Ramos
This study aimed to compare the between-session reliability of the load–velocity relationship between (1) linear versus polynomial regression models, (2) concentric-only versus eccentric–concentric bench press variants, as well as (3) the within-participants versus the between-participants variability of the velocity attained at each percentage of the 1-repetition maximum. The load–velocity relationship of 30 men (age: 21.2 [3.8] y; height: 1.78 [0.07] m, body mass: 72.3 [7.3] kg; bench press 1-repetition maximum: 78.8 [13.2] kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric–concentric bench press variants in a Smith machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order polynomials (coefficient of variation: 4.39%–4.70%) provided the load–velocity relationship with higher reliability than the second-order polynomials (coefficient of variation: 4.68%–5.04%); (2) the reliability of the load–velocity relationship did not differ between the concentric-only and eccentric–concentric bench press variants; and (3) the within-participants variability of the velocity attained at each percentage of the 1-repetition maximum was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load–velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.
Alejandro Pérez-Castilla, Belén Feriche, Slobodan Jaric, Paulino Padial and Amador García-Ramos
This study aimed to examine the validity of mechanical variables obtained by a linear velocity transducer from the unconstrained and constrained squat jump (SJ). Twenty-three men were tested on the unconstrained SJ and the SJ constrained by a Smith machine. Maximum values of force, velocity, and power were simultaneously recorded both by a linear velocity transducer attached to a bar of mass of 17, 30, 45, 60, and 75 kg and by a force plate. Linear velocity transducer generally overestimated the outcomes measured as compared to the force plate, particularly in unconstrained SJ. Bland-Altman plots revealed that heteroscedasticity of errors was mainly observed for velocity variables (r 2 = .26–.58) where the differences were negatively associated with the load magnitude. However, exceptionally high correlations were observed between the same outcomes recorded with the 2 methods in both unconstrained (median r = .89 [.71–.95]) and constrained SJ (r = .90 [.65–.95]). Although the systematic and proportional bias needs to be acknowledged, the high correlations between the variables obtained by 2 methods suggest that the linear velocity transducer could provide valid values of the force, velocity, and power outputs from both unconstrained and constrained SJ.
Amador García-Ramos, Alejandro Torrejón, Alejandro Pérez-Castilla, Antonio J. Morales-Artacho and Slobodan Jaric
Purpose: To explore the feasibility of the linear force–velocity (F–V) modeling approach to detect selective changes of F–V parameters (ie, maximum force [F 0], maximum velocity [V 0], F–V slope [a], and maximum power [P 0]) after a sprint-training program. Methods: Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F–V parameters through the application of the multiple-point method (4 resistances used for the F–V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used). Results: Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation <5% and intraclass correlation coefficients >.80) while also being able to detect the group-specific training-related changes. Large increments of F 0, a, and P 0 were observed in HLG compared with LLG and CG (effect size [ES] = 1.29–2.02). Moderate increments of V 0 were observed in LLG compared with HLG and CG (ES = 0.87–1.15). Conclusions: Short-term sprint training on a leg cycle ergometer induces specific changes in F–V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.
Amador García-Ramos, Francisco Luis Pestaña-Melero, Alejandro Pérez-Castilla, Francisco Javier Rojas and Guy Gregory Haff
Purpose: To compare the load–velocity relationship between 4 variants of the bench-press (BP) exercise. Methods: The full load–velocity relationship of 30 men was evaluated by means of an incremental loading test starting at 17 kg and progressing to the individual 1-repetition maximum (1RM) in 4 BP variants: concentric-only BP, concentric-only BP throw (BPT), eccentric-concentric BP, and eccentric-concentric BPT. Results: A strong and fairly linear relationship between mean velocity (MV) and %1RM was observed for the 4 BP variants (r 2 > .96 for pooled data and r 2 > .98 for individual data). The MV associated with each %1RM was significantly higher in the eccentric-concentric technique than in the concentric-only technique. The only significant difference between the BP and BPT variants was the higher MV with the light to moderate loads (20–70%1RM) in the BPT using the concentric-only technique. MV was significantly and positively correlated between the 4 BP variants (r = .44–.76), which suggests that the subjects with higher velocities for each %1RM in 1 BP variant also tend to have higher velocities for each %1RM in the 3 other BP variants. Conclusions: These results highlight the need for obtaining specific equations for each BP variant and the existence of individual load–velocity profiles.
Amador García-Ramos, Alejandro Torrejón, Antonio J. Morales-Artacho, Alejandro Pérez-Castilla and Slobodan Jaric
This study determined the optimal resistive forces for testing muscle capacities through the standard cycle ergometer test (1 resistive force applied) and a recently developed 2-point method (2 resistive forces used for force-velocity modelling). Twenty-six men were tested twice on maximal sprints performed on a leg cycle ergometer against 5 flywheel resistive forces (R1–R5). The reliability of the cadence and maximum power measured against the 5 individual resistive forces, as well as the reliability of the force-velocity relationship parameters obtained from the selected 2-point methods (R1–R2, R1–R3, R1–R4, and R1–R5), were compared. The reliability of outcomes obtained from individual resistive forces was high except for R5. As a consequence, the combination of R1 (≈175 rpm) and R4 (≈110 rpm) provided the most reliable 2-point method (CV: 1.46%–4.04%; ICC: 0.89–0.96). Although the reliability of power capacity was similar for the R1–R4 2-point method (CV: 3.18%; ICC: 0.96) and the standard test (CV: 3.31%; ICC: 0.95), the 2-point method should be recommended because it also reveals maximum force and velocity capacities. Finally, we conclude that the 2-point method in cycling should be based on 2 distant resistive forces, but avoiding cadences below 110 rpm.
Alejandro Pérez-Castilla, Antonio Piepoli, Gabriel Garrido-Blanca, Gabriel Delgado-García, Carlos Balsalobre-Fernández and Amador García-Ramos
Objective: To compare the accuracy of different devices to predict the bench-press 1-repetition maximum (1RM) from the individual load–velocity relationship modeled through the multiple- and 2-point methods. Methods: Eleven men performed an incremental test on a Smith machine against 5 loads (45–55–65–75–85%1RM), followed by 1RM attempts. The mean velocity was simultaneously measured by 1 linear velocity transducer (T-Force), 2 linear position transducers (Chronojump and Speed4Lift), 1 camera-based optoelectronic system (Velowin), 2 inertial measurement units (PUSH Band and Beast Sensor), and 1 smartphone application (My Lift). The velocity recorded at the 5 loads (45–55–65–75–85%1RM), or only at the 2 most distant loads (45–85%1RM), was considered for the multiple- and 2-point methods, respectively. Results: An acceptable and comparable accuracy in the estimation of the 1RM was observed for the T-Force, Chronojump, Speed4Lift, Velowin, and My Lift when using both the multiple- and 2-point methods (effect size ≤ 0.40; Pearson correlation coefficient [r] ≥ .94; standard error of the estimate [SEE] ≤ 4.46 kg), whereas the accuracy of the PUSH (effect size = 0.70–0.83; r = .93–.94; SEE = 4.45–4.80 kg), and especially the Beast Sensor (effect size = 0.36–0.84; r = .50–.68; SEE = 9.44–11.2 kg), was lower. Conclusions: These results highlight that the accuracy of 1RM prediction methods based on movement velocity is device dependent, with the inertial measurement units providing the least accurate estimate of the 1RM.
Ramón Marcote-Pequeño, Amador García-Ramos, Víctor Cuadrado-Peñafiel, Jorge M. González-Hernández, Miguel Ángel Gómez and Pedro Jiménez-Reyes
Purpose: To quantify the magnitude of the association between the same variables of the force–velocity (FV) profile and the performance variables (unloaded-squat-jump height and 20-m sprint time) obtained during jumping and sprinting testing and to determine which mechanical capacity (ie, maximum force [F 0], maximum velocity [V 0], or maximum power [P max]) presents the highest association with the performance variables. Methods: The FV profile of 19 elite female soccer players (age 23.4 [3.8] y, height 166.4 [5.6] cm, body mass 59.7 [4.7] kg) was determined during the jumping and sprinting tasks. The F 0, V 0, FV slope, P max, and FV imbalance (difference respect to the optimal FV profile in jumping and the decrease in the ratio of horizontal force production in sprinting) were determined for each task. Results: Very large correlations between both tasks were observed for P max (r = .75) and the performance variables (r = −.73), as well as moderate correlations for V 0 (r = .49), while the F 0 (r = −.14), the FV slope (r = −.09), and the FV imbalance (r = .07) were not significantly correlated between both tasks. The P max obtained during each specific task was the mechanical capacity most correlated with its performance variable (r = .84 in jumping and r = .99 in sprinting). Conclusions: The absence of significant correlations between some of the FV relationship parameters suggests that, for an individualized training prescription based on the FV profile, both jumping and sprinting testing procedures should be performed with elite female soccer players.
Amador García-Ramos, Alejandro Torrejón, Belén Feriche, Antonio J. Morales-Artacho, Alejandro Pérez-Castilla, Paulino Padial and Guy Gregory Haff
Purpose: To provide 2 general equations to estimate the maximum possible number of repetitions (XRM) from the mean velocity (MV) of the barbell and the MV associated with a given number of repetitions in reserve, as well as to determine the between-sessions reliability of the MV associated with each XRM. Methods: After determination of the bench-press 1-repetition maximum (1RM; 1.15 ± 0.21 kg/kg body mass), 21 men (age 23.0 ± 2.7 y, body mass 72.7 ± 8.3 kg, body height 1.77 ± 0.07 m) completed 4 sets of as many repetitions as possible against relative loads of 60%1RM, 70%1RM, 80%1RM, and 90%1RM over 2 separate sessions. The different loads were tested in a randomized order with 10 min of rest between them. All repetitions were performed at the maximum intended velocity. Results: Both the general equation to predict the XRM from the fastest MV of the set (CV = 15.8–18.5%) and the general equation to predict MV associated with a given number of repetitions in reserve (CV = 14.6–28.8%) failed to provide data with acceptable between-subjects variability. However, a strong relationship (median r 2 = .984) and acceptable reliability (CV < 10% and ICC > .85) were observed between the fastest MV of the set and the XRM when considering individual data. Conclusions: These results indicate that generalized group equations are not acceptable methods for estimating the XRM–MV relationship or the number of repetitions in reserve. When attempting to estimate the XRM–MV relationship, one must use individualized relationships to objectively estimate the exact number of repetitions that can be performed in a training set.