Effects of a 16-week High-Speed Resistance Training program on body composition in community-dwelling independent older adults: A clinical trial

BACKGROUND & AIMS

Aging frequently causes changes in body composition, such as a loss of strength and muscular mass and an increase in fat mass. Exercise training programs have been suggested as effective strategies to mitigate or prevent age-related declines in body composition. Therefore, this study examined the effects of a sixteen-week High-Speed Resistance Training (HSRT) program on body composition parameters in community-dwelling independent older adults.

METHODS

The present clinical trial included 79 older adults, who were divided into two groups: intervention group (IG, N = 40, age, 68.50 ± 3.54 years; weight, 68.65 ± 11.36 kg) and control group (CG, N = 39, age, 72.08 ± 5.89 years; weight, 67.04 ± 10.69 kg). IG performed the supervised HSRT for 16 weeks, with 3 sessions per week of 60-70min, each session of 5-6 exercises, 2-3 sets, and 6-10 reps/exercise, while CG did not perform any exercise training program. Body composition parameters were assessed using a multifrequency tetrapolar bioelectrical impedance analyzer (InBody® S10). The level of physical activity and the dietary intake were evaluated by the International Physical Activity Questionnaire (IPAQ-SF) and the Food Frequency Questionnaire, respectively. Statistical analyses were performed using the analysis of covariance (ANCOVA), and effect size (Cohen's dunbiased).

RESULTS

The analysis showed significant effects of the group factor for IG on phase angle (F(1) = 14.39, p < 0.001, η2p = 0.159). Additionally, results from Δ changes (post-minus pre-values) revealed small and medium effects in favor to IG for body cell mass (t(77) = 1.21, p = 0.230, dunb = 0.27 [-0.17, 0.71]) and phase angle (t(77) = 2.82, p = 0.006, dunb = 0.63 [0.18, 1.08]), respectively.

CONCLUSIONS

The HSRT could effectively prevent the decline in cellular health and cell integrity in older adults, as evidenced by the significant improvements in the phase angle.

REGISTRATION

Clinicaltrial.gov (ID: NCT05586087).

Frequency of Velocity-Based-Training Frequency Impacts Changes in Muscle Morphology, Neuromuscular Performance, and Functional Capability in Persons With Parkinson's Disease

ABSTRACT

Calaway, C, Walls, K, Levitt, H, Caplan, J, Mann, B, Martinez, K, Gastaldo, R, Haq, I, and Signorile, JF. Frequency of velocity-based-training frequency impacts changes in muscle morphology, neuromuscular performance and functional capability in persons with Parkinson's disease. J Strength Cond Res XX(X): 000-000, 2024-Velocity-based training (VBT) positively impacts muscle morphology and performance in persons with Parkinson's disease (PD); however, optimal training frequencies for VBT in patients with PD remain undetermined. Changes in ultrasound-determined muscle thickness (MT) and echo intensity (EI)-derived muscle quality of the rectus femoris (RF) and vastus lateralis (VL), neuromuscular performance, and functional capacity were examined following 2 VBT frequencies (2-3 d·wk-1) using 30% velocity loss thresholds for 12 weeks. Neuromuscular performance was assessed using computerized pneumatic resistance machines. For each variable, 2 (time) × 2 (group) repeated-measures analyses of variance (ANOVA) were used to determine significant main effects and interactions. Significant time effects were seen for MT and EI of all muscles (p < 0.05). Muscle thickness improvements included right VL (RVL) (0.171 ± 0.065 cm; p = 0.019), left VL (LVL) (0.214 ± 0.101 cm; p = 0.049), right RF (RRF) (0.194 ± 0.077 cm; p = 0.023), and left RF (LRF) (0.318 ± 0.109 cm; p = 0.010). For EI, improvements occurred in RVL (-18.688 ± 3.600; p = <0.001), LVL (-10.959 ± 4.894; p = 0.040), RRF (-9.516 ± 3.537; p = 0.016), and LRF (-9.018 ± 3.444; p = 0.019). Time effects were seen for leg-press 1-repetition maximum and peak power (p < 0.01) and habitual walking speed (p = 0.022), with a group by time interaction for maximal gait speed favoring the 3 d·wk-1 condition (∆0.15 m·s-1, p = 0.002). The results indicate that VBT at 2 or 3 d·wk-1 can significantly improve muscle morphology, neuromuscular performance, and functional capability in patients with PD; however, improvements in maximal gait speed require 3 d·wk-1. These findings provide flexibility when developing exercise prescriptions for patients with PD.

Autoregulation Does Not Provide Additional Benefits to a Mixed Session Periodized Resistance Training Program in Trained Men

ABSTRACT

Bartolomei, S, Francesco, L, Latini, D, and Hoffman, JR. Autoregulation does not provide additional benefits to a mixed session periodized resistance training program in trained men. J Strength Cond Res 38(9): 1535-1542, 2024-The aim of this investigation was to study how autoregulation impacted training volume, performance, and muscle size on a 10-week mixed session periodized (MSP) resistance training program, characterized by the inclusion of different training foci in each session. Twenty-four resistance trained men were assigned to an autoregulated mixed session periodized (AMSP group; n = 13; age = 26.2 ± 4.9 y; body mass = 82.0 ± 8.7 kg; height = 176.8 ± 6.0 cm) or into an MSP ( n = 11; age = 24.0 ± 2.6; body mass = 81.3 ± 10.5 kg; height = 174.0 ± 5.4 cm) group. Subjects in both groups trained 5 days per week for 10 weeks and performed the same exercises. The difference between the groups consisted in the use of a perceived recovery-based scale to adjust the individual training volume in the AMSP program. Maximal strength (bench press and squat 1 repetition maximum), power (bench press throw and countermovement jump), and muscle architecture (muscle thickness [MT] of biceps brachii, trapezius, vastus lateralis and vastus medialis) were collected before and after the 10-week training period. In addition, training volume and session load were calculated for each training session. A higher total training volume ( p < 0.001) was seen in AMSP program compared with MSP program, but no differences ( p > 0.05) were noted in the average session load. No significant differences between the groups were detected for MT of both upper-body and lower-body muscles ( p's > 0.05) and lean body mass ( p = 0.681). No significant differences between the groups were detected for any strength or power measurements. Results of this study indicate that a perceived recovery-based AMSP training program was not more effective than an MSP training program for increasing muscle size and performance in resistance trained men.

Velocity-Based Training Affects Function, Strength, and Power in Persons with Parkinson's Disease

ABSTRACT

Calaway, CC, Martinez, KJ, Calzada Bichili, AR, Caplan, JH, Milgrim, WP, Mann, JB, Haq, I, and Signorile, JF. Velocity-based training affects function, strength, and power in persons with Parkinson's disease. J Strength Cond Res XX(X): 000-000, 2024-Velocity-based training (VBT) is commonly associated with high-level athletes. No study has examined the effects of VBT on performance in persons with Parkinson's disease (PD). The objective of the study was to compare the effects of 10 and 30% velocity-loss threshold protocols on changes in functional performance, strength, and power in persons with PD after 12 weeks of supervised VBT, 3 days per week. Twenty-one subjects with PD (72.9 ± 5.9 y) were randomly assigned to the 10% or 30% velocity-loss threshold group and performed the 6-m walk test at habitual and maximal gait speed (6MWTMax), the 5 time sit-to-stand test (5 × STS), 1 repetition maximum (1RM), and peak power (PP) testing for the chest press (CP) and leg press (LP) exercise. A mixed ANOVA with significance was set a priori at 0.05 revealed that significant time effects were seen for the 6MWT at maximal speed (MDiff ± SD = 0.22 ± 0.04 m·s-1, p < 0.001), 5-time sit-to-stand time (-1.48 ± 0.45 seconds, p = 0.005) and power (75.5 ± 22.7 W, p = 0.005), 1RM for CP (5.1 ± 1.1 kg, p < 0.001) and LP (12.6 ± 3.7 kg, p = 0.005), and LP-PP (43.6 ± 13.2 W, p = 0.006). Secondary analyses revealed time effects for the load at which PP was achieved for the CP exercise. A Wilcoxon signed-rank test revealed no significant differences in the percentage of 1RM at which PP was achieved for either condition. Results indicate that VBT is an effective training modality for improving functional capacity, strength, and power in persons with PD; however, shifts in force-velocity relationships were not evidenced.

Enhancing Training Precision: Unveiling the Barbell Velocity's Role in Tailoring the Resistance Load for the China Badminton Team

Velocity-based resistance training is a fundamental component of sports science, offering a systematic approach to investigating the load variables of resistance exercises. This research focused on assessing the load across various resistance exercises by examining the barbell velocity during the concentric phase. The study involved 11 male athletes representing the China badminton team, who underwent 1RM testing for bench press, hip thrust, back squat, and single leg press exercises and the maximum repetition testing at load intensities of 60%, 70%, 80%, and 90% of 1RM. Simultaneously, measurements were taken of the barbell's concentric phase velocity during each exercise. The findings revealed a robust negative correlation between barbell velocity and load intensity. Furthermore, exercises engaging greater muscle strength displayed smoother fitting curves. Analysis of velocity loss rates indicated that the hip thrust exhibited a higher completion percentage compared to the back squat and the bench press. Similarly, the non-dominant leg press showed a higher completion percentage than the dominant leg press. The study emphasizes the significance of delineating barbell velocity distributions in resistance training involving large muscle groups, as well as the accurate determination of load intensity. Precise load determination can be facilitated by employing fitting curves derived from distinct movement patterns and varying load intensities. The utilization of velocity data offers a quantifiable approach to achieving targeted training outcomes.

The Impact of Velocity-Based Training on Load-Velocity Relationships in Leg Press and Chest Press for Older Persons

ABSTRACT

Calaway, C, Mishra, S, Parrino, R, Martinez, KJ, Mann, JB, and Signorile, JF. Velocity-based training affects the load-velocity relationship in leg press and chest press for older persons. J Strength Cond Res 38(6): 1136-1143, 2024-This study examined the impact of 3 months of velocity-based training (VBT) on chest press (CP) and leg press (LP) maximal strength (1 repetition maximum [1RM]), peak power (PP), and percentage load where PP was achieved (%1RMPP) in older adults. Twenty-nine subjects were assigned to either a velocity-deficit (VD) group or a force-deficit (FD) group for each exercise depending on their load-velocity (LV) curves. Changes in load were determined by the ability to maintain either 90% (VD) or 70% (FD) of their PP during training. Subjects' powers were tested before and after the training intervention at loads between 40 and 80%1RM. Separate 2 (group) × 2 (time) ANOVA was used to examine changes in each variable by group for each exercise. Wilcoxon signed-rank tests were used to determine whether significant changes in %1RMPP for each exercise and group. For chest press 1 repetition maximum, there were no significant main effects or interaction. Significant main effects for time were observed for leg press 1 repetition maximum ( p < 0 .001, η2 = 0.547) and chest press peak power ( p = 0.009, η2 = 0.243). For LPPP, there were no significant main effects or interactions. For %1RMPP, CP median scores revealed no significant changes for either group. Significant declines in %1RMPP were observed for leg press velocity-deficit and leg press force-deficit ( p < 0.03) groups. Velocity-based training was effective at improving 1RM, PP, and shifting %1RMPP in the LP groups. These results have implications for targeting power improvements at specific areas of the LV curve. Health care providers and trainers should consider these findings when constructing exercise programs to counter age-related declines in older adults.

The enhancement of explosive power contributes to the development of anaerobic capacity: A comparison of autoregulatory progressive resistance exercise and velocity-based resistance training

Objectives

Due to the character of the taekwondo, the adenosine triphosphate-phosphocreatine system provides the energy for each kick, the glycolytic system supports the repeated execution of kicks, and the aerobic system promotes recovery between these movements and the bout. Therefore, taekwondo athletes require high explosive power and anaerobic capacity in order to carry out sustained and powerful attacks. So, the purpose of this study is to compare the effects of APRE and VBRT on lower-limb explosive power and anaerobic capacity in college taekwondo players.

Methods

A total of 30 taekwondo players completed an 8-week training intervention with autoregulatory progressive resistance exercise (APRE; n = 15) and velocity-based resistance training (VBRT; n = 15). Testing included the one-repetition maximum squat, countermovement jump (CMJ), taekwondo anaerobic intermittent kick test (TAIKT), and 30-s Wingate anaerobic test (WAnT).

Results

(1) Intragroup comparisons revealed significant effects for one-repetition maximum squat, peak power of CMJ (CMJPP), relative peak power of CMJ (CMJRPP), and total number of TAIKT (TAIKTTN) in both the APRE and VBRT groups. The VBRT group exhibited small effect sizes for time at peak power of WAnT (WAnTPPT) and moderate effect sizes for peak power of WAnT (WAnTPP), relative peak power of WAnT (WAnTRPP), and fatigue index of TAIKT (TAIKTFI), whereas the APRE group exhibited small effect sizes for TAIKTFI. (2) Intergroup comparisons revealed no significant effects in any of the results. However, VBRT demonstrated a moderate advantage in WAnTPP and WAnTRPP, whereas APRE had a small advantage in CMJPP and CMJRPP.

Conclusions

These findings suggest that APRE improved explosive power (CMJPP and CMJRPP) more, whereas VBRT improved anaerobic power output (WAnTPP and WAnTRPP) more. Both methods were found to have similar effects in improving the anaerobic endurance (WAnTPPT and TAIKTTN) and fatigue index (power drop of WAnT and TAIKTFI).

Resistance Training Intensity Prescription Methods Based on Lifting Velocity Monitoring

Resistance training intensity is commonly quantified as the load lifted relative to an individual's maximal dynamic strength. This approach, known as percent-based training, necessitates evaluating the one-repetition maximum (1RM) for the core exercises incorporated in a resistance training program. However, a major limitation of rigid percent-based training lies in the demanding nature of directly testing the 1RM from technical, physical, and psychological perspectives. A potential solution that has gained popularity in the last two decades to facilitate the implementation of percent-based training involves the estimation of the 1RM by recording the lifting velocity against submaximal loads. This review examines the three main methods for prescribing relative loads (%1RM) based on lifting velocity monitoring: (i) velocity zones, (ii) generalized load-velocity relationships, and (iii) individualized load-velocity relationships. The article concludes by discussing a number of factors that should be considered for simplifying the testing procedures while maintaining the accuracy of individualized L-V relationships to predict the 1RM and establish the resultant individualized %1RM-velocity relationship: (i) exercise selection, (ii) type of velocity variable, (iii) regression model, (iv) number of loads, (v) location of experimental points on the load-velocity relationship, (vi) minimal velocity threshold, (vii) provision of velocity feedback, and (viii) velocity monitoring device.

Validity of Using the Load-Velocity Relationship to Estimate 1 Repetition Maximum in the Back Squat Exercise: A Systematic Review and Meta-Analysis

ABSTRACT

LeMense, AT, Malone, GT, Kinderman, MA, Fedewa, MV, and Winchester, LJ. Validity of using the load-velocity relationship to estimate 1 repetition maximum in the back squat exercise: a systematic review and meta-analysis. J Strength Cond Res 38(3): 612-619, 2024-The one repetition maximum (1RM) test is commonly used to assess muscular strength. However, 1RM testing can be time consuming, physically taxing, and may be difficult to perform in athletics team settings with practice and competition schedules. Alternatively, 1RM can be estimated from bar or movement velocity at submaximal loads using the minimum velocity threshold (MVT) method based on the load-velocity relationship. Despite its potential utility, this method's validity has yielded inconsistent results. The purpose of this systematic review and meta-analysis was to assess the validity of estimated 1RM from bar velocity in the back squat exercise. A systematic search of 3 electronic databases was conducted using combinations of the following keywords: "velocity-based training," "load-velocity profiling," "mean velocity," "mean propulsive velocity," "peak velocity," "maximal strength," "1RM," "estimation," "prediction," "back squat," and "regression." The search identified 372 unique articles, with 4 studies included in the final analysis. Significance was defined as a p level less than 0.05. A total of 27 effects from 71 subjects between the ages of 17-25 years were analyzed; 85.2% of effects were obtained from male subjects. Measured 1RMs ranged from 86.5 to 153.1 kg, whereas estimated 1RMs ranged from 88.6 to 171.6 kg. Using a 3-level random effects model, 1RM back squat was overestimated when derived from bar velocity using the MVT method (effect sizes [ES] = 0.5304, 95% CI: 0.1878-0.8730, p = 0.0038). The MVT method is not a viable option for estimating 1RM in the free weight back squat. Strength and conditioning professionals should exercise caution when estimating 1RM from the load-velocity relationship.

The Validity of Perceptual Recovery Status on Monitoring Recovery During a High-Intensity Back-Squat Session

Adaptations to resistance training and subsequent performance can be undermined by inadequate interset recovery. Methods typically used to monitor recovery were developed for longitudinal use, making them time-inefficient within singular exercise bouts. If valid, perceptual recovery status (PRS) may be used as an efficient and inexpensive assessment tool to monitor individual recovery.

PURPOSE

The aim of this study was to assess the validity of PRS on monitoring recovery during a high-intensity back-squat session.

METHODS

Ten healthy men participated in the 2-session study (separated by at least 48 h). Session 1 included anthropometrics, PRS familiarization, and a 1-repetition-maximum back squat. Session 2 included a high-intensity protocol (5 sets of 5 repetitions; 5-min interset recovery; 85% of 1-repetition maximum). PRS was obtained before the first set and during the last 30 seconds of each 5-minute recovery; rating of perceived exertion (RPE) was also collected. A linear position transducer collected mean barbell velocity (MBV). Repeated-measures correlations assessed the common intraindividual relationships of PRS scores to intraset MBV and RPE, respectively.

RESULTS

A very large, positive correlation appeared between PRS and MBV (r [95% CI] = .778 [.613 to .878]; P < .0001). A large, negative correlation emerged between PRS and RPE (r [95% CI] = -.549 [-.737 to -.282]; P < .001).

CONCLUSIONS

Results indicate that PRS can be a means for practitioners to monitor individualized recovery. PRS tracked well with RPE, strengthening its utility in a practitioner-based setting. Findings provide insight into the practicality of PRS for recovery monitoring. It could be used alongside other measures (eg, MBV and countermovement jump) to individually program and maintain performance.

Effects of a Strength and Conditioning Offseason Program on Countermovement Jump Ground Reaction Forces in Division I American Football Players

ABSTRACT

Gillen, ZM, Burch, RF, Saucier, DN, Strawderman, L, Luczak, T, Piroli, A, Petway, AJ, and Rath, T. Effects of a strength and conditioning offseason program on countermovement jump ground reaction forces in Division I American football players. J Strength Cond Res 38(3): e86-e95, 2024-The purpose of this study was to examine the effects of a 10-week strength and conditioning offseason program on the ground reaction forces (GRFs) of American football players during single-leg and double-leg countermovement jumps (SLJ and CMJ, respectively). Each subject visited the laboratory twice, once for preoffseason and once for postoffseason testing. During each visit, subjects performed CMJs and SLJs for each leg. Ground reaction forces were collected by force plates to quantify unweighting, braking, propulsive, and performance metrics for each jump. In addition, an efficiency index was calculated for each jump to examine changes in vertical jump efficiency. Dependent samples t tests compared all CMJ metrics. Two-way repeated measures analyses of variance (leg × time) compared all SLJ metrics. An alpha level of p ≤ 0.05 was considered statistically significant. For the CMJ, propulsive phase duration decreased due to the program ( p = 0.007), whereas peak braking power, peak propulsive power, mean propulsive force, and jump height increased ( p ≤ 0.012). For the SLJ, peak braking power, force at the low position, braking rate of force development, eccentric force, peak propulsive power, mean propulsive force, and jump height increased in both legs ( p ≤ 0.044). The efficiency index increased for the CMJ and the SLJ for both legs ( p ≤ 0.016). This study demonstrated that SLJ and CMJ vertical jump performance significantly increases in as few as 10 weeks of offseason strength and conditioning. Strength and conditioning programming may effectively increase vertical jump performance, as assessed by GRFs, which can be used as a simple indicator regarding changes in athletic performance.

The validity of the Push Band 2.0 to determine speed and power during progressively loaded squat jumps

ABSTARCTThe PUSH band 2.0 is a wearable technology used to measure mean and peak velocity and power in strength-based movements. The agreement between the PUSH band 2.0 and the criterion measure (force plates) during progressively loaded squat jumps was assessed. Fifteen participants performed 3 squat jumps at increasing loads. Linear regression and Bland-Altman plots assessed data simultaneously recorded from both devices. Mean velocity and power showed deviation from the identity line and an overestimation of 7.40% and 25%, respectively. Peak velocity and power showed an overestimation of 14% and underestimation of 6%, respectively. The results support the use of Push Band 2.0 to measure velocity during ballistic squat movements. However, errors in power measurement are greater than acceptable to support in-field use. While peak velocity maintains a consistent overestimation bias across various velocities, mean velocity error increases at higher velocities and can only be considered valid at slow velocities.

Validity of a Smartphone App Using Artificial Intelligence for the Real-Time Measurement of Barbell Velocity in the Bench Press Exercise

ABSTRACT

Balsalobre-Fernández, C, Xu, J, Jarvis, P, Thompson, S, Tannion, K, and Bishop, C. Validity of a smartphone app using artificial intelligence for the real-time measurement of barbell velocity in the bench press exercise. J Strength Cond Res 37(12): e640-e645, 2023-The purpose of this study was to explore the validity and within-session reliability of the newly developed My Jump Lab application (app), which uses artificial intelligence techniques to monitor barbell velocity in real time. Twenty-seven sport science students performed 5 repetitions at 50 and 75% of their self-reported bench press 1 repetition maximum (1RM) during a single testing session, whereas barbell velocity was concurrently measured using the app (installed on an iPhone 12 Pro) and the GymAware linear position transducer (LPT). A very high correlation was observed between devices at each loading condition (50% 1RM: r = 0.90 [0.82-0.97]; 75% 1RM: r = 0.92 [0.86-0.98]). Results showed trivial differences between the app and LPT at both 50% 1RM (g = -0.06) and 75% 1RM (g = -0.12). Bland-Altman analysis showed a bias estimate of -0.010 m·s-1 and -0.026 m·s-1 for the 50 and 75% 1RM, respectively. Finally, similar levels of reliability, as revealed by the coefficient of variation, were observed for both devices (50% 1RM: LPT = 6.52%, app = 8.17%; 75% 1RM: LPT = 12.10%, app = 13.55%). Collectively, the findings of this study support the use of My Jump Lab for the measurement of real-time barbell velocity in the bench press exercise.

A Novel Approach to Determining the Alactic Time Span in Connection with Assessment of the Maximal Rate of Lactate Accumulation in Elite Track Cyclists

PURPOSE

Following short-term all-out exercise, the maximal rate of glycolysis is frequently assessed on the basis of the maximal rate of lactate accumulation in the blood. Since the end of the interval without significant accumulation (talac) is 1 of 2 denominators in the calculation employed, accurate determination of this parameter is crucial. Although the very existence and definition of talac, as well as the validity of its determination as time-to-peak power (tPpeak), remain controversial, this parameter plays a key role in anaerobic diagnostics. Here, we describe a novel approach to determination of talac and compare it to the current standard.

METHODS

Twelve elite track cyclists performed 3 maximal sprints (3, 8, and 12 s) and a high-rate, low-resistance pedaling test on an ergometer with monitoring of crank force and pedaling rate. Before and after each sprint, capillary blood samples were taken for determination of lactate accumulation. Fatigue-free force-velocity and power-velocity profiles were generated. talac was determined as tPpeak and as the time point of the first systematic deviation from the force-velocity profile (tFf).

RESULTS

Accumulation of lactate after the 3-second sprint was significant (0.58 [0.19] mmol L-1; P < .001, d = 1.982). tFf was <3 seconds and tPpeak was ≥3 seconds during all sprints (P < .001, d = - 2.111). Peak power output was lower than maximal power output (P < .001, d = -0.937). Blood lactate accumulation increased linearly with increasing duration of exercise (R2 ≥ .99) and intercepted the x-axis at ∼tFf.

CONCLUSION

Definition of talac as tPpeak can lead to incorrect conclusions. We propose determination of talac based on tFf, the end of the fatigue-free state that may reflect the beginning of blood lactate accumulation.

The Effect of Velocity Loss on Strength Development and Related Training Efficiency: A Dose-Response Meta-Analysis

The velocity loss method is often used in velocity-based training (VBT) to dynamically regulate training loads. However, the effects of velocity loss on maximum strength development and training efficiency are still unclear. Therefore, we conducted a dose-response meta-analysis aiming to fill this research gap. A systematic literature search was performed to identify studies on VBT with the velocity loss method via PubMed, Web of Science, Embase, EBSCO, and Cochrane. Controlled trials that compared the effects of different velocity losses on maximum strength were considered. One-repetition maximum (1RM) gain and 1RM gain per repetition were the selected outcomes to indicate the maximum strength development and its training efficiency. Eventually, nine studies with a total of 336 trained males (training experience/history ≥ 1 year) were included for analysis. We found a non-linear dose-response relationship (reverse U-shaped) between velocity loss and 1RM gain (pdose-response relationship < 0.05, pnon-linear relationship < 0.05). Additionally, a negative linear dose-response relationship was observed between velocity loss and 1RM gain per repetition (pdose-response relationship < 0.05, pnon-linear relationship = 0.23). Based on our findings, a velocity loss between 20 and 30% may be beneficial for maximum strength development, and a lower velocity loss may be more efficient for developing and maintaining maximum strength. Future research is warranted to focus on female athletes and the interaction of other parameters.

The effects of velocity-based versus percentage-based resistance training on athletic performances in sport-collegiate female basketball players

Introduction: The study compared the effects of 6-week (2 sessions/week) velocity-based resistance training (VBRT) and percentage-based resistance training (PBRT) on athletic performance in Sport-College female basketball players. Methods: Fifteen participants were assigned to the VBRT (n = 8) or PBRT (n = 7) groups. The load in VBRT group were determined through the sessional target velocity and velocity loss monitoring, whereas PBRT group used a fixed-load based on percentage of 1-repetition maximum (1RM). Both groups completed intervention that involved the free weight back squat and bench press using the same relative load (linear periodization from 65% to 95% 1RM). Training loads data was continuously recorded. Measurements at baseline (T0) and post-training (T2) included 1RM, countermovement-jump (CMJ), squat-jump (SJ), eccentric-utilization-ratio (EUR), drop-jump height and reactive-strength-index (DJ, DJ-RSI), plyometric-push-up (PPU), 505 change-of-direction (COD), 10-m、20-m sprint (T-10、T-20), 17 × 15 m drill-lines (17-drill), Hexagon agility, and functional movement screen (FMS). A mid-term (T1) assessment was included to investigate the short-term effects of both methods and the fluctuation of personalized 1RM. Results: No between-group differences were observed at T0 for descriptive variables (p > 0.05). Both groups showed significant improvement in strength gains for back squat and bench press, but VBRT showed likely to very likely favorable improvements in CMJ, SJ, EUR, DJ-RSI, Hexagon and COD among athletic performance. The VBRT showed likely to very likely improvements in 17-drill and DJ, while PBRT showed unclear effects. The lifted weights adjusted by VBRT method were higher than prescribed by PBRT (p < 0.05) for the same subjects. Conclusion: Compared with fixed-load PBRT, VBRT enhanced power and athletic performance despite similar strength gains. VBRT can be regarded as a more functional resistance-training method under linear periodization.

Perception of Bar Velocity Loss in Resistance Exercises: Accuracy Across Loads and Velocity Loss Thresholds in the Bench Press

PURPOSE

Velocity-based training is used to prescribe and monitor resistance training based on velocity outputs measured with tracking devices. When tracking devices are unavailable or impractical to use, perceived velocity loss (PVL) can be used as a substitute, assuming sufficient accuracy. Here, we investigated the accuracy of PVL equal to 20% and 40% relative to the first repetition in the bench-press exercise.

METHODS

Following a familiarization session, 26 resistance-trained men performed 4 sets of the bench-press exercise using 4 different loads based on their individual load-velocity relationships (∼40%-90% of 1-repetition maximum [1RM]), completed in a randomized order. Participants verbally reported their PVL at 20% and 40% velocity loss during the sets. PVL accuracy was calculated as the absolute difference between the timing of reporting PVL and the actual repetition number corresponding to 20% and 40% velocity loss measured with a linear encoder.

RESULTS

Linear mixed-effects model analysis revealed 4 main findings. First, across all conditions, the absolute average PVL error was 1 repetition. Second, the PVL accuracy was not significantly different between the PVL thresholds (β = 0.16, P = .267). Third, greater accuracy was observed in loads corresponding to the midportion of the individual load-velocity relationships (∼50%-60% 1RM) compared with lighter (<50% 1RM, β = 0.89, P < .001) and heavier loads (>60% 1RM, 0.63 ≤ β ≤ 0.84, all P values < .001). Fourth, PVL accuracy decreased with consecutive repetitions (β = 0.05, P = .017).

CONCLUSIONS

PVL can be implemented as a monitoring and prescription method when velocity-tracking devices are impractical or absent.

The effect of high and low velocity-based training on the throwing performance of collegiate handball players

Background

The intensity of strength training exercise is generally regarded to be the most essential element in developing muscle strength and power. The exercise intensity of strength training is known as one-repetition maximum (1RM). Velocity-based training (VBT) has been proposed as a different approach for determining training intensity. VBT relies on the use of linear position transducers and inertial measurement units, providing real-time feedback to objectively adjust the exercise intensity based on an athlete's velocity zone.

Methods

This study investigated the effects of two different training interventions based on individualized load velocity profiles (LVP) on maximal bench press strength (i.e., 1RM), maximum throwing velocity (TV), and skeletal muscle mass (SKMM). Twenty-two university handball players were randomly assigned to Group 1 (low-movement speed training) or Group 2 (high-movement speed training). Group 1 exercised with a bar speed of 0.75-0.96 m/s, which corresponds to a resistance of approximately 60% 1RM, whereas Group 2 trained at 1.03-1.20 m/s, corresponding to a resistance of approximately 40% 1RM. Both groups exercised three times a week for five weeks, with strength and throwing tests performed at baseline and post-intervention.

Results

A two-way repeated measures ANOVA was applied, and the results showed the interaction between group and time was not statistically significant for SKMM (p = 0.537), 1RM (p = 0.883), or TV (p = 0.774). However, both groups significantly improved after the five weeks of training: SKMM (3.1% and 3.5%, p < 0.01), 1RM (15.5% and 15.0%, p < 0.01), and throwing velocity (18.7% and 18.3%, p < 0.01) in Group 1 and 2 respectively. Training at both prescribed velocities in this study elicited similar changes in strength, muscle mass, and throwing velocity.

Fatigue-Free Force-Velocity and Power-Velocity Profiles for Elite Track Sprint Cyclists: The Influence of Duration, Gear Ratio and Pedalling Rates

Background: Maximal force-velocity (F/v) profiles for track cyclists are commonly derived from ergometer sprints using an isovelocity or isoinertial approach. Previously, an attempt was made to derive maximal F/v profiles from a single maximal 65-m sprint on the cycling track. Hypothesising that this approach may not accurately reflect the fatigue-free F/v profile, we propose an alternative procedure and compare it to the previous method. Moreover, we test for the impact of gear ratio on diagnostic results. Methods: Twelve elite track cyclists completed a high-cadence low-resistance pedalling test on a freestanding roller (motoric test) and two series of three maximal 65-m sprints on a cycling track with different gear ratios. F/v profiles were calculated based on the measured crank force and cadence either during the first 6−7 revolutions (≤6 s) on the track (model I) or were derived from the first 3−4 revolutions (≤3 s) on the track combined with 1 or 2 fatigue-free cycles at cadences above 160 rpm from the motoric test (model II). Results: Although both models exhibit high-to-excellent linearity between force and velocity, the extrapolated isometric force was higher (1507.51 ± 257.60 N and 1384.35 ± 276.84 N; p < 0.002; d = 2.555) and the slope steeper (−6.78 ± 1.17 and −5.24 ± 1.11; p < 0.003, d = −2.401) with model I. An ICC of 1.00 indicates excellent model consistency when comparing the F/v profiles (model II) derived from the different geared sprints. Conclusions: Assuring fatigue-free measurements and including high-cadence data points in the calculations provide valid maximal F/v and P/v profiles from a single acceleration-sprint independent of gear ratio.

The Role of Velocity-Based Training (VBT) in Enhancing Athletic Performance in Trained Individuals: A Meta-Analysis of Controlled Trials

Velocity-based training (VBT) is a rising auto-regulation method that dynamically regulates training loads to promote resistance training. However, the role of VBT in improving various athletic performances is still unclear. Hence, the presented study aimed to examine the role of VBT in improving lower limbs’ maximum strength, strength endurance, jump, and sprint performance among trained individuals. A systematic literature search was performed to identify studies on VBT for lower limb strength training via databases, including PubMed, Web of Science, Embase, EBSCO, Cochrane, CNKI (in Chinese), and Wanfang Database (in Chinese). Controlled trials that deployed VBT only without extra training content were considered. Eventually, nine studies with a total of 253 trained males (at least one year of training experience) were included in the meta-analysis. The pooled results suggest that VBT may effectively enhance lower limbs’ maximum strength (SMD = 0.76; p < 0.001; I2 = 0%), strength endurance (SMD = 1.19; p < 0.001; I2 = 2%), countermovement jump (SMD = 0.53; p < 0.001; I2 = 0%), and sprint ability (SMD of sprint time = −0.40; p < 0.001; I2 = 0%). These findings indicate the positive role of VBT in serving athletic training. Future research is warranted to focus on the effect of velocity loss of VBT on athletic performance.

Effect of Augmented Feedback on Velocity Performance During Strength-Oriented and Power-Oriented Resistance Training Sessions

ABSTRACT

Jiménez-Alonso, A, García-Ramos, A, Cepero, M, Miras-Moreno, S, Rojas, FJ, and Pérez-Castilla, A. Effect of augmented feedback on velocity performance during strength-oriented and power-oriented resistance training sessions. J Strength Cond Res 36(6): 1511-1517, 2022-This study examined the effects of providing instantaneous velocity feedback (knowledge of results [KR]) on velocity maintenance across multiple sets during strength-oriented and power-oriented resistance training (RT) sessions. Seventeen men completed 2 strength-oriented RT sessions (4 sets of 5 repetitions at 75% of 1 repetition maximum [1RM] during the back squat [SQ] and bench press [BP] exercises) in 1 week and 2 power-oriented RT sessions (4 sets of 5 repetitions at 30% of 1RM during the countermovement jump [CMJ] and BP throw [BPT] exercises) in another week. Subjects received verbal velocity performance feedback in 1 session (KR) and no KR was provided in another session. Greater velocities during the 4 sets of both strength-oriented (from 4.6 to 11.6%) and power-oriented (from 1.4 to 3.5%) RT sessions were observed. The increments in velocity performance during the KR condition were greater for the CMJ (2.25 ± 0.14 vs. 2.18 ± 0.17 m·s-1; 3.0%) than the BPT (2.33 ± 0.13 vs. 2.29 ± 0.16 m·s-1; 1.7%) and similarly for the SQ (0.59 ± 0.07 vs. 0.55 ± 0.06 m·s-1; 7.5%) and BP (0.47 ± 0.09 vs. 0.44 ± 0.07 m·s-1; 7.8%). The raw differences in the RT velocity for BPT were positively correlated with the raw differences in the RT velocity for SQ (r = 0.524; p = 0.031) and CMJ (r = 0.662; p = 0.004), but the remaining correlations did not reach a statistical significance (r ≤ 0.370; p ≥ 0.123). Although these results support the provision of velocity performance feedback to increase training quality regardless of the type of RT session, the positive effect of KR seems to be more accentuated during strength-oriented compared with power-oriented RT sessions.

Velocity Performance Feedback During the Free-Weight Bench Press Testing Procedure: An Effective Strategy to Increase the Reliability and One Repetition Maximum Accuracy Prediction

ABSTRACT

Jiménez-Alonso, A, García-Ramos, A, Cepero, M, Miras-Moreno, S, Rojas, FJ, and Pérez-Castilla, A. Velocity performance feedback during the free-weight bench press testing procedure: An effective strategy to increase the reliability and one repetition maximum accuracy prediction. J Strength Cond Res 36(4): 1077-1083, 2022-This study aimed to determine whether the verbal provision of velocity performance feedback during the free-weight bench press (BP) exercise influences (a) the within-session reliability and magnitude of mean concentric velocity (MCV) values recorded against a range of submaximal loads and (b) the accuracy of the individualized load-velocity profile to estimate the BP 1 repetition maximum (1RM). Fifteen men (BP 1RM relative to body mass = 1.08 ± 0.22) performed an incremental loading test until reaching the 1RM on 2 separate sessions. Subjects received verbal velocity performance feedback in 1 session (knowledge of results [KR]), and no KR was provided in another session (Control). A linear velocity transducer was used to collect the MCV against 4 loads (40-55-70-85% 1RM), and the BP 1RM was estimated from the individualized load-velocity relationship modeled through the multiple-point (40-55-70-85% 1RM) and 2-point methods (40-85% 1RM). The KR condition provided a higher reliability (coefficient of variation [CV]: KR = 2.41%, Control = 3.54%; CV ratio = 1.47) and magnitude (p = 0.001; effect size [ES] = 0.78) of MCV for the 40% 1RM, but no significant differences in reliability (CV ratio ≤1.15) nor in the magnitude (p ≥ 0.058; ES range = 0.00-0.32) were observed for higher loads. The accuracy in the estimation of the 1RM was higher for the KR (absolute errors: multiple-point = 3.1 ± 2.3 kg; 2-point = 3.5 ± 2.1 kg) compared with the Control condition (absolute errors: 4.1 ± 1.9 kg for both multiple-point and 2-point methods). These results encourage the provision of verbal velocity performance feedback during BP testing procedures.

Using cluster and rest redistribution set structures as alternatives to resistance training prescription method based on velocity loss thresholds

Background

The purpose of this study was to compare the effects of cluster (CS), rest redistribution (RR) and traditional (TS) set configurations on acute neuromuscular performance, and to determine the viability of using CS and RR as alternatives to training prescription based on velocity loss (VL).

Methods

Thirty-one resistance-trained men performed, in a randomised order, three experimental sessions consisting of the squat (SQ) and bench press (BP) exercises performed against the 10-repetition maximum load using CS (three sets of six repetitions; 30 s of intra-set rest every two repetitions; 3 min of inter-set rest), RR (9 sets of two repetitions; 45 s of inter-set rest), and TS (3 sets of 6 repetitions; 3 min of inter-set rest), set configurations.

Results

Linear mixed-effects model analysis revealed that participants had significantly lower VL (p = 0.0005) during CS and RR than TS. Generalised mixed-effects model analysis yielded significant main effects of set structure (p < 0.0001; RR > CS > TS), exercise (p < 0.0001; SQ > BP), and set number (p = 0.0006; Set 1 > Set 2 > Set 3) for maintaining repetition velocity above a 20% VL threshold.

Conclusions

These findings suggest that CS and RR are effective at reducing the overall fatigue-included decrease in velocity compared to TS and allow the majority of repetitions to be completed with less than 20% VL. Therefore, both CS and RR can be used to manage fatigue during resistance training, and as alternatives to training prescription method based on 20% VL threshold.

Comparison of Velocity and Percentage-based Training on Maximal Strength：Meta-Analysis

The purpose was to analyze the comparison of velocity-based resistance training and one-repetition maximum (%1RM) percentage-based training in maximal strength improvement by meta-analyzing and to find the reasons for the controversial findings of different studies. Ten studies were included in the systematic review and seven were subjected to meta-analysis. A total of 139 subjects were selected from the included articles after exclusion, including athletes of different specialties (N=93) and non-athletes mainly from fitness groups (N=46). The overall effect size was SMD=0.26 (95%CL 0.03 to 0.49, P=0.03, I²=0). As for the comparison of the analysis of different intervention objects as subgroups, the effect size of athletes as the subgroup was 0.35 (95%CI 0.06 to 0.64, p=0.02, I²=0), indicating that in the RCT with athletes as the intervention target, the effect of VBRT in improving the maximal strength was significantly different from that of PBT. Velocity-based resistance training might be more effective than percentage-based training in maximal strength improvement, in which velocity-based resistance training is more suitable for athletes in season, while percentage-based training is more suitable for the general sports population. More high-quality researches should deal with the effect of other athletic performance with velocity-based resistance training in the future.

Reliability and validity of the multi-point method and the 2-point method's variations of estimating the one-repetition maximum for deadlift and back squat exercises

This study aimed at examining the concurrent validity and reliability of the multi-point method and the two-point method's variations for estimating the one-repetition maximum (1RM) in the deadlift and squat exercises and to determine the accuracy of which optimal two loads can be used for the two-point method protocol. Thirteen resistance-trained men performed six sessions that consisted of two incremental loading tests (multi-point method: 20-40-60-80-90% and two-point method variations: 40-60%, 40-80%, 40-90%,60-80%, 60-90%) followed by 1RM tests. Both the multi-point method and the two-point method load variations showed reliable results for 1RM estimation (CV < 10%) squat and deadlift exercises. Session-session reliability was found to be low in deadlift (ICC: 0.171-0.335) and squat exercises (ICC: 0.235-0.479) of 40-60% and 60-80% in two-point methods. Deadlift (ICC: 0.815-0.996) and squat (ICC: 0.817-0.988) had high session-to-session reliability in all other methods. Regarding the validity of deadlift exercise, the multipoint method (R² = 0.864) and two variations of the two-point method (R² = 0.816 for 40-80%, R² = 0.732 for 60-80%) showed very large correlations, whereas other two variations of the two-point method (R² = 0.945 for 40-90%, R² = 0.914 for 60-90%) showed almost perfect correlations with the actual 1RM. Regarding the validity of squat exercise, the multi-point method (R² = 0.773) and two variations of the two-point method (R² = 0.0847 for 60-80%, R² = 0.705 for 40-90%) showed very large correlations, whereas 40-60% variation showed almost perfect correlation (R² = 0.962) with the actual 1RM. In conclusion, whereas both the multi-point method and the two-point method load variations showed reliable results, the multiple-point method and most of the two-point methods' load variations examined in this research provided an accurate (from large-moderate to perfect) estimate of the 1RM. Therefore, we recommend using the multi-point method and especially the two-point methods variations including higher relative loads to estimate 1RM.

Predicting performance on the NFL-225 bench press test using bar velocity

BACKGROUND: Bar velocity has been proved to accurately predict performance in several exercises. OBJECTIVE: To estimate the total number of repetitions during the NFL-225 Bench Press Test (NFL-225) based on bar velocity in collegiate football players. METHODS: Forty-six NCAA Division I football players performed as many bench press repetitions as possible with a standard load of 225 lbs. The variables used to estimate the total number of repetitions were: mean velocity of the fastest repetition achieved in the test (FR); mean velocity of the first repetition (V1); mean velocity of the first three repetitions (MV3); mean velocity of the first five repetitions (MV5); and mean velocity of the first 10 repetitions (MV10). Linear regression analyses were conducted to predict NFL-225 performance based on bar velocity. RESULTS: The prediction of the total number of repetitions was similar between the five mean velocities (FR: R2= 0.64, SEE = 3.87, V1: R2= 0.65, SEE = 3.80, MV3: R2= 0.70, SEE = 3.52, MV5: R2= 0.71, SEE = 3.48, and MV10: R2= 0.62, SEE = 3.37). CONCLUSION: The mean velocities allowed the production of general regression equations for the estimation of the total number of repetitions in the NFL-225. V1 and MV3 presented as the best options due to their accuracy, time-efficiency, and reduced musculoskeletal stress.

A systematic review of resistance training methodologies for the development of lower body concentric mean power, peak power, and mean propulsive power in team-sport athletes

This study aimed to systematically review training methods prescribed to develop lower-body power, determine their effectiveness for the development of lower-body mechanical power and their implementation in an annual training cycle amongst team-sport athletes. The absolute and relative outcome values of concentric mean power, peak power and mean propulsive power were extracted from 19 studies. Outcomes were assessed using baseline to post intervention percent change, effect sizes, and the level of evidence concerning the method's effectiveness. A thorough analysis of the literature indicated that, based on the high level of evidence, traditional (e.g., strength training alone) and combination training (e.g., complex and contrast) methods should be considered. Further, optimal load and velocity-based training can be implemented if coaches have access to the appropriate equipment to monitor movement velocity and mechanical power in every session. This is of particular importance in periods of the season where high volumes of technical-tactical training and congested fixture periods are present. Also, flywheel, eccentric overload and weightlifting methods have been shown to be effective although the level of evidence is low. Future research should expand on current training practices whilst adequately reporting actual training loads from sport-specific training and games alongside strength-power training protocols.

Validity and Reliability of the Inertial Measurement Unit for Barbell Velocity Assessments: A Systematic Review

The use of inertial measurement unit (IMU) has become popular in sports assessment. In the case of velocity-based training (VBT), there is a need to measure barbell velocity in each repetition. The use of IMUs may make the monitoring process easier; however, its validity and reliability should be established. Thus, this systematic review aimed to (1) identify and summarize studies that have examined the validity of wearable wireless IMUs for measuring barbell velocity and (2) identify and summarize studies that have examined the reliability of IMUs for measuring barbell velocity. A systematic review of Cochrane Library, EBSCO, PubMed, Scielo, Scopus, SPORTDiscus, and Web of Science databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From the 161 studies initially identified, 22 were fully reviewed, and their outcome measures were extracted and analyzed. Among the eight different IMU models, seven can be considered valid and reliable for measuring barbell velocity. The great majority of IMUs used for measuring barbell velocity in linear trajectories are valid and reliable, and thus can be used by coaches for external load monitoring.

Perception of changes in bar velocity as a resistance training monitoring tool for athletes

PURPOSE

To investigate if perception of changes in bar velocity (PCV) can be used as a substitute for velocity tracking devices commonly used to monitor resistance-exercises.

METHODS

Twenty-one professional male soccer athletes (21±4 years) first went through a load-power profile assessment to determine their optimal power load in the back-squat. In the next three experimental sessions, athletes completed four sets of six repetitions loaded with optimal power load. Starting from the second repetition, athletes reported their PCV of each repetition as a percentage of the first repetition. Accuracy of PCV was calculated as the absolute difference between PCV and the actual percentage change from the first repetition in bar velocity measured with a linear-encoder. The second and fourth sessions served as the pre- and post-intervention sessions, in which athletes received no feedback about their PCV accuracy. The third session served as the intervention session, in which athletes received verbal and visual feedback about their PCV accuracy levels after each set.

RESULTS

The estimated accuracy of PCV decreased from an average error of 7% in the pre-intervention to an average error of 4.7% in the post-intervention session (95% confidence levels of difference: 1.5, 3.0).

CONCLUSION

Athletes with velocity based training experience begin with a reasonable PCV accuracy rates which can be meaningfully improved after a single session that includes accuracy feedback. When velocity tracking devices are impractical or absent, PCV can be implemented as a resistance training monitoring tool.

Jump Training in Rugby Union Players: Barbell or Hexagonal Bar?

ABSTRACT

Weakley, JJS, Till, K, Read, DB, Leduc, C, Roe, GAB, Phibbs, PJ, Darrall-Jones, J, and Jones, B. Jump training in rugby union players: barbell or hexagonal bar?. J Strength Cond Res 35(3): 754-761, 2021-The countermovement jump (CMJ) is an exercise that can develop athletic performance. Using the conventional barbell (BAR) and hexagonal barbell (HEX) while jumping, the intensity can be increased. However, the bar that provides greater adaptations is unknown. Therefore, this study aimed to assess changes in loaded and unloaded CMJ with either a BAR or HEX across a 4-week mesocycle in rugby union players. Twenty-nine subjects were strength-matched and randomized into 2 groups. Subjects completed 3 sets of CMJ at 20% of 1 repetition maximum back squat, 3 times per week for 4 weeks, using either a BAR or HEX. Subjects completed an unloaded CMJ on a force plate before and after, whereas the highest peak concentric velocity during the jump squat was recorded in the first and last training sessions using a linear position transducer. Magnitude-based inferences assessed meaningful changes within- and between-groups. Possibly greater improvements in unloaded CMJ were found in the HEX group in jump height (effect size ± 90% confidence intervals: 0.27 ± 0.27), relative peak (0.21 ± 0.23), and mean power (0.32 ± 0.36). In addition, likely to very likely greater improvements were observed in the HEX group in peak velocity (0.33 ± 0.27), relative mean power (0.53 ± 0.30), mean force (0.47 ± 0.27), and 100-ms impulse (0.60 ± 0.48). Similar raw changes in jump squat peak velocity occurred (0.20-0.25 m·s-1), despite the likely greater ES occurring with the BAR (0.32 ± 0.26). These results indicate that training with the HEX leads to superior unloaded CMJ adaptations. In addition, practitioners should use either the HEX or BAR when aiming to enhance loaded jump ability.

Reliability and Validity of the iLOAD Application for Monitoring the Mean Set Velocity During the Back Squat and Bench Press Exercises Performed Against Different Loads

ABSTRACT

Pérez-Castilla, A, Boullosa, D, and García-Ramos, A. Reliability and validity of the iLOAD application for monitoring the mean set velocity during the back squat and bench press exercises performed against different loads. J Strength Cond Res 35(2S): S57-S65, 2021-This study aimed to evaluate the reliability and validity of a smartphone application (iLOAD) for the monitoring of mean concentric velocity (MV) during resistance training sets. Twenty males completed 2 identical sessions consisting of one set of 10 repetitions against 4 loads (25, 40, 55, 70% of the one repetition maximum [1RM]) during the back squat and bench press exercises. The MV of the 5 initial repetitions and for the whole set were determined simultaneously with the iLOAD application and a linear velocity transducer (LVT). Two independent researchers operated the iLOAD application during the experimental sessions to evaluate the interrater agreement for the assessment of MV. An acceptable but generally lower reliability was observed for iLOAD (coefficient of variation [CV] range: 5.61-9.79%) compared to the LVT (CV range: 4.51-8.18%) at 25-40-55% of 1RM, whereas the reliability at 75% of 1RM was acceptable for the LVT during the bench press (CV range: 6.37-8.26%), but it was unacceptable for the iLOAD during both exercises (CV range: 11.3-12.8%) and for the LVT during the back squat (CV range: 11.3-17.4%). Small to moderate differences (ES range: 0.24-1.04) and very high to practically perfect correlations (r range: 0.70-0.90) were observed between the iLOAD and the LVT. A very high agreement was observed between both raters for the recording of MV during the back squat and bench press exercises (r ≥ 0.98). Taken together, these results suggest that the iLOAD application can be confidently used to quantify the MV of training sets during the squat and bench press exercises not performed to failure.

The Bench Press Grip Width Does Not Affect the Number of Repetitions Performed at Different Velocity Loss Thresholds

This study aimed (I) to compare the number of repetitions that can be completed to failure (XRM) and before reaching a 15%, 30%, or 45% velocity loss threshold (XVLT) in the bench press exercise performed using different grip widths, and (II) to examine the inter-individual variability in the percentage of completed repetitions with respect to the XRM when the set volume is prescribed based on a fixed number of repetitions (FNR) and several velocity loss thresholds (VLT). Nineteen men performed four separate sessions in a random order where there was a single set of repetitions completed to failure against 75% of the one-repetition maximum during the Smith machine bench press exercise using a narrow, medium, wide, or self-selected grip widths. The XRM (p = 0.545) and XVLTs (p ≥ 0.682) were not significantly affected by grip width. A high and comparable inter-individual variability in the percentage of completed repetitions with respect to the XRM was observed when using both an FNR (median CV = 24.3%) and VLTs (median CV = 23.5%). These results indicate that Smith machine bench press training volume is not influenced by the grip width and that VLTs do not allow a more homogeneous prescription of the set volume with respect to the XRM than the traditional FNR.

The effects of verbal cueing for high intended movement velocity on power, neuromuscular activation, and performance

It is widely believed that lifting heavy loads slowly, but with a conscious intention to move at high velocity, can produce resistance training (RT) adaptations indicative of rapid movements. This study investigated the effects of verbally cued high "intended" movement velocity (HIMV) during RT on neuromuscular and performance outcomes. 20 untrained volunteers (aged 24.2 ± 3.9 years) participated in 3 weeks of knee extension training. Participants were randomly allocated to receive verbal cues focusing on high intended movement velocity, HIMV, or steady and controlled movement, TRAD (traditional training). All other training variables, including actual movement velocity (30° s^-1 ), remained constant. Increase in mean power output at 30° s^-1 was greater for TRAD than HIMV (76% and 33%, respectively, P = 0.027). There were main effects for time (but no between-group differences) for maximal isometric force (+14%, P = 0.003), peak torque at 180° s^-1 (+22%, P = 0.006), peak torque at 30° s^-1 (+29%, P < 0.001), 3-repetition maximum (+20%, P < 0.001), and resting corticospinal excitability (+43%, P = 0.017). There were no differences between groups or across time for voluntary activation (P = 0.793), spinal excitability (P = 0.686), or intracortical inhibition (all P > 0.05). HIMV verbal cueing did not produce additional neurophysiological or performance benefits when compared to traditional cueing. Overall, our results demonstrated that verbal cueing did not alter the principle of velocity-specific adaptation. Cueing that increases the duration of maximal effort may be optimal for maximizing average power output at low speeds.

The Validity and Reliability of Commercially Available Resistance Training Monitoring Devices: A Systematic Review

Background

Monitoring resistance training has a range of unique difficulties due to differences in physical characteristics and capacity between athletes, and the indoor environment in which it often occurs. Traditionally, methods such as volume load have been used, but these have inherent flaws. In recent times, numerous portable and affordable devices have been made available that purport to accurately and reliably measure kinetic and kinematic outputs, potentially offering practitioners a means of measuring resistance training loads with confidence. However, a thorough and systematic review of the literature describing the reliability and validity of these devices has yet to be undertaken, which may lead to uncertainty from practitioners on the utility of these devices.

Objective

A systematic review of studies that investigate the validity and/or reliability of commercially available devices that quantify kinetic and kinematic outputs during resistance training.

Methods

Following PRISMA guidelines, a systematic search of SPORTDiscus, Web of Science, and Medline was performed; studies included were (1) original research investigations; (2) full-text articles written in English; (3) published in a peer-reviewed academic journal; and (4) assessed the validity and/or reliability of commercially available portable devices that quantify resistance training exercises.

Results

A total of 129 studies were retrieved, of which 47 were duplicates. The titles and abstracts of 82 studies were screened and the full text of 40 manuscripts were assessed. A total of 31 studies met the inclusion criteria. Additional 13 studies, identified via reference list assessment, were included. Therefore, a total of 44 studies were included in this review.

Conclusion

Most of the studies within this review did not utilise a gold-standard criterion measure when assessing validity. This has likely led to under or overreporting of error for certain devices. Furthermore, studies that have quantified intra-device reliability have often failed to distinguish between technological and biological variability which has likely altered the true precision of each device. However, it appears linear transducers which have greater accuracy and reliability compared to other forms of device. Future research should endeavour to utilise gold-standard criterion measures across a broader range of exercises (including weightlifting movements) and relative loads.

Electronic supplementary material

The online version of this article (10.1007/s40279-020-01382-w) contains supplementary material, which is available to authorized users.

Acute and Delayed Effects of a Resistance Training Session Leading to Muscular Failure on Mechanical, Metabolic, and Perceptual Responses

Párraga-Montilla, JA, García-Ramos, A, Castaño-Zambudio, A, Capelo-Ramírez, F, González-Hernández, JM, Cordero-Rodríguez, Y, and Jiménez-Reyes, P. Acute and delayed effects of a resistance training session leading to muscular failure on mechanical, metabolic, and perceptual responses. J Strength Cond Res 34(8): 2220-2226, 2020-This study explored the acute and delayed (24 and 48 hours after exercise) effects of a resistance training session leading to muscular failure. Eleven resistance-trained men completed a training session consisting on 3 sets of repetitions to failure during the back-squat exercise performed at the maximum possible speed with a load equivalent to a mean propulsive velocity (MPV) of 1 m·s (≈60% of 1 repetition maximum). A number of mechanical (number of repetitions and starting MPV of the set, MPV achieved against the 1MPV load, countermovement jump [CMJ] height, and handgrip strength), metabolic (lactate, uric acid, and ammonia concentrations), and perceptual (OMNI-RES perceived exertion) variables were measured. The results revealed (a) a decrease of 38.7% in set 2 and 54.7% in set 3 of the number of repetitions performed compared with the first set (p < 0.05), (b) a reduction in the MPV of the repetitions and an increase in lactate concentration and OMNI-RES values with the succession of sets (p < 0.05), (c) comparable decrements in CMJ height after the 3 sets (25-32%), (d) a decrease in CMJ height (p < 0.05; 6.7-7.9%) and in the MPV attained against the 1MPV load (p < 0.05; 13-14%) after 24 and 48 hours of completing the training session, but no significant changes were observed in handgrip strength (p > 0.05; <2%), and (e) uric acid and ammonia concentrations above the basal levels (p < 0.05). The large decrements in mechanical performance together with the high metabolic stress discourage the frequent use of resistance training sessions leading to muscular failure.

Validity and Reliability of Methods to Determine Barbell Displacement in Heavy Back Squats: Implications for Velocity-Based Training

Appleby, BB, Banyard, H, Cormack, SJ, and Newton, RU. Validity and reliability of methods to determine barbell displacement in heavy back squats: Implications for velocity-based training. J Strength Cond Res 34(11): 3118-3123, 2020-The purpose of this study was to investigate the validity and reliability of methods for determining barbell displacement during heavy back squats. Twelve well-trained rugby union players (mean ± SD 1 repetition maximum [1RM] 90° squat = 196.3 ± 29.2 kg) completed 2 sets of 2 repetitions at 70, 80, and 90% of 1RM squats. Barbell displacement was derived from 3 methods across 4 load categories (120-129, 140-149, 160-169, and 180-189 kg) including: a (a) linear position transducer (LPT) attached 65 cm left of barbell center, (b) 3D motion analysis tracking of markers attached to either end of a barbell, and (c) cervical marker (C7) (criterion measurement). Validity was calculated using the typical error of the estimate as a coefficient of variation (CV%) ±90% confidence interval (CI), mean bias as a percentage, and the Pearson product moment correlation (r). Intraday reliability was calculated using the intraclass correlation coefficient and the typical error expressed as a percentage of CV% ±90% (CI). Mean displacement for C7, LPT, and the barbell ends was 520, 529, and 550-564 mm, respectively. Validity of the LPT compared with the criterion was acceptable (CV% = 2.1-3.0; bias = 0.9-1.5%; r = 0.96-0.98), whereas that of the barbell ends was less (CV% = 2.7-7.5; bias = 4.9-11.2%; r = 0.71-0.97). The CV% reliability of the C7 marker across the load categories was 6.6%, the LPT 6.6%, and the barbell ends between 5.9 and 7.2%. Despite reliable measures, overestimation of displacement occurs as the tracking location moves to the barbell ends in weighted back squats. The LPT demonstrated high validity to the criterion and high trial-to-trial reliability.

Autoregulation in Resistance Training: Addressing the Inconsistencies

Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties.

Myosin heavy chain expression relationships to power-load and velocity-load curves

BACKGROUND

Velocity- and power-based training are popular methods of determining training session loads and volumes. One factor that may influence load-velocity and load-power properties of an individual is the myosin heavy chain (MHC) composition of the muscle. The aim of this study was to examine the relationship between MHC composition and both load-velocity and load-power properties of muscle performance.

METHODS

Forty-two men with a variety of training backgrounds took part in this study (mean±SD; age=22.4±3.5 yrs, hgt=1.78±0.07 m, BW=78.7±13.3 kg). After testing leg extension one repetition maximum (1 RM), subjects performed maximal effort leg extensions at loads from 30% to 90% 1 RM. Muscle biopsies from the vastus lateralis were analyzed via SDS-PAGE electrophoresis technique for MHC content (IIx=13.8±12.9%, IIa=49.4±10.3%, I=36.8±11.3%). Leg extension rotational velocity and power were plotted against relative loads for all subjects.

RESULTS

Significant correlations (P<0.05) were observed for MHC IIa with all performance variables (i.e. slopes, intercepts, peaks and relative loads). Relationships indicated that greater %MHC IIa was associated with greater velocity intercepts, more negative load-velocity slopes, greater maximal power, and with maximal power occurring at a lower relative intensity (% 1 RM).

CONCLUSIONS

These data indicate that muscle velocity and power characteristics appear to be partially influenced by MHC content in a manner consistent with single muscle fiber contractile properties.

Velocity Performance Feedback During Ballistic Training: Which Is the Optimal Frequency of Feedback Administration?

This study explored the impact of different frequencies of knowledge of results (KR) on velocity performance during ballistic training. Fifteen males completed four identical sessions (three sets of six repetitions at 30% one-repetition maximum during the countermovement jump and bench press throw) with the only difference of the KR condition provided: no feedback, velocity feedback after the first half of repetitions of each set (HalfKR), velocity feedback immediately after each repetition (ImKR), and feedback of the average velocity of each set (AvgKR). When compared with the control condition, the ImKR reported the highest velocity performance (1.9-5.3%), followed by the HalfKR (1.3-3.6%) and AvgKR (0.7-4.3%). These results support the verbal provision of velocity performance feedback after every repetition to induce acute improvements in velocity performance.

Changes in the Load-Velocity Profile Following Power- and Strength-Oriented Resistance-Training Programs

OBJECTIVE

To compare the short-term effect of power- and strength-oriented resistance-training programs on the individualized load-velocity profiles obtained during the squat (SQ) and bench-press (BP) exercises.

METHODS

Thirty physically active men (age = 23.4 [3.5] y; SQ 1-repetition maximum [1RM] = 126.5 [26.7] kg; BP 1RM = 81.6 [16.7] kg) were randomly assigned to a power- (exercises: countermovement jump and BP throw; sets per exercise: 4-6; repetitions per set: 5-6; load: 40% 1RM) or strength-training group (exercises: SQ and BP; sets per exercise: 4-6; repetitions per set: 2-8; load: 70%-90% 1RM). The training program lasted 4 wk (2 sessions/wk). The individualized load-velocity profiles (ie, velocity associated with the 30%-60%-90% 1RM) were assessed before and after training through an incremental loading test during the SQ and BP exercises.

RESULTS

The power-training group moderately increased the velocity associated with the full spectrum of % 1RM for the SQ (effect size [ES] range: 0.70 to 0.93) and with the 30% 1RM for the BP (ES: 0.67), while the strength-training group reported trivial/small changes across the load-velocity spectrum for both the SQ (ES range: 0.00 to 0.35) and BP (ES range: -0.06 to -0.33). The power-training group showed a higher increase in the mean velocity associated with all % 1RM compared with the strength-training group for both the SQ (ES range: 0.54 to 0.63) and BP (ES range: 0.25 to 0.53).

CONCLUSIONS

The individualized load-velocity profile (ie, velocity associated with different % 1RM) of lower-body and upper-body exercises can be modified after a 4-wk resistance-training program.

Superior Changes in Jump, Sprint, and Change-of-Direction Performance but Not Maximal Strength Following 6 Weeks of Velocity-Based Training Compared With 1-Repetition-Maximum Percentage-Based Training

PURPOSE

To compare the effects of velocity-based training (VBT) and 1-repetition-maximum (1RM) percentage-based training (PBT) on changes in strength, loaded countermovement jump (CMJ), and sprint performance.

METHODS

A total of 24 resistance-trained males performed 6 weeks of full-depth free-weight back squats 3 times per week in a daily undulating format, with groups matched for sets and repetitions. The PBT group lifted with fixed relative loads varying from 59% to 85% of preintervention 1RM. The VBT group aimed for a sessional target velocity that was prescribed from pretraining individualized load-velocity profiles. Thus, real-time velocity feedback dictated the VBT set-by-set training load adjustments. Pretraining and posttraining assessments included the 1RM, peak velocity for CMJ at 30%1RM (PV-CMJ), 20-m sprint (including 5 and 10 m), and 505 change-of-direction test (COD).

RESULTS

The VBT group maintained faster (effect size [ES] = 1.25) training repetitions with less perceived difficulty (ES = 0.72) compared with the PBT group. The VBT group had likely to very likely improvements in the COD (ES = -1.20 to -1.27), 5-m sprint (ES = -1.17), 10-m sprint (ES = -0.93), 1RM (ES = 0.89), and PV-CMJ (ES = 0.79). The PBT group had almost certain improvements in the 1RM (ES = 1.41) and possibly beneficial improvements in the COD (ES = -0.86). Very likely favorable between-groups effects were observed for VBT compared to PBT in the PV-CMJ (ES = 1.81), 5-m sprint (ES = 1.35), and 20-m sprint (ES = 1.27); likely favorable between-groups effects were observed in the 10-m sprint (ES = 1.24) and nondominant-leg COD (ES = 0.96), whereas the dominant-leg COD (ES = 0.67) was possibly favorable. PBT had small (ES = 0.57), but unclear differences for 1RM improvement compared to VBT.

CONCLUSIONS

Both training methods improved 1RM and COD times, but PBT may be slightly favorable for stronger individuals focusing on maximal strength, whereas VBT was more beneficial for PV-CMJ, sprint, and COD improvements.

Load-velocity relationship of the deadlift exercise

Velocity-based training (VBT) is gaining popularity in strength and conditioning due to multiple practical advantages for auto-regulating and individualizing training volume and load on a day-to-day basis. Because the load-velocity relationship varies among exercises, the knowledge of particular equations is indispensable to effectively implement the VBT. The aim of this study was to determine the complete load- and power-velocity profile of the deadlift exercise to provide practical equations and normative values for resistance training coaches and practitioners. Twenty strength-trained men performed a progressive loading test at maximal intended velocity to determine their one-repetition maximum (1RM). Mean (MV), mean propulsive (MPV) and peak velocity (PV) were measured during the concentric phase. Both MV and MPV showed a very close relationship to %1RM (R² = 0.971 and R² = 0.963) with a low error of estimation (SEE = 0.08 and 0.09 m·s^-1), which was maintained throughout the wide breadth of velocities. PV showed the poorest results (R² = 0.958, SEE = 0.15 m·s^-1). MV attained with the 1RM was 0.24 ± 0.03 m·s^-1 and consistent between participants with different relative strengths. The load that maximized the power output was identified at ∼60% 1RM. In contrast to what was observed in velocity, power outcomes showed poor predictive capacity to estimate %1RM. Hence, the use of velocity-based equations is advisable to monitor athletes' performance and adjust the training load in the deadlift exercise. This finding provides an alternative to the demanding, time-consuming and interfering 1RM tests, and allows the use of the deadlift exercise following the VBT principles.

Influence of Grip Width and Anthropometric Characteristics on the Bench-Press Load-Velocity Relationship

PURPOSE

To compare the load-velocity (L-V) relationship between bench-press exercises performed using 4 different grip widths, to determine the association between the anthropometric characteristics and L-V profile, and to explore whether a multiple linear-regression model with movement velocity and subjects' anthropometric characteristics as predictor variables could increase the goodness of fit of the individualized L-V relationship.

METHODS

The individual L-V relationship of 20 men was evaluated by means of an incremental loading test during the bench-press exercise performed on a Smith machine using narrow, medium, wide, and self-selected grip widths. Simple and multiple linear-regression models were performed.

RESULTS

The mean velocity associated with each relative load did not differ among the 4 grip widths (P ≥ .130). Only body height and total arm length were correlated with the mean velocity associated with light and medium loads (r ≥ .464). A slightly higher variance of the velocity attained at each relative load was explained when some anthropometric characteristics were used as predictor variables along with the movement velocity (r2 = .969 [.965-.973]) in comparison with the movement velocity alone (r2 = .966 [.955-.968]). However, the amount of variance explained by the individual L-V relationships was always higher than with the multiple linear-regression models (r2 = .995 [.985-1.000]).

CONCLUSIONS

These results indicate that the individual determination of the L-V relationship using a self-selected grip width could be recommended to monitor relative loads in the Smith machine bench-press exercise.

Validation of Inertial Sensor to Measure Barbell Kinematics across a Spectrum of Loading Conditions

The aim of this study was to evaluate the level of agreement in measuring back squat kinematics between an inertial measurement unit (IMU) and a 3D motion capture system (3DMOCAP). Kinematic variables included concentric peak velocity (CPV), concentric mean velocity (CMV), eccentric peak velocity (EPV), eccentric mean velocity (EMV), mean propulsive velocity (MPV), and POP-100: a proprietary variable. Sixteen resistance-trained males performed an incrementally loaded one repetition maximum (1RM) squat protocol. A series of Pearson correlations, 2 × 4 RM ANOVA, Cohen’s d effect size differences, coefficient of variation (CV), and standard error of the estimate (SEE) were calculated. A large relationship existed for all variables between devices (r = 0.78–0.95). Between-device agreement for CPV worsened beyond 60% 1RM. The remaining variables were in agreement between devices with trivial effect size differences and similar CV magnitudes. These results support the use of the IMU, regardless of relative intensity, when measuring EMV, EPV, MPV, and POP-100. However, practitioners should carefully select kinematic variables of interest when using the present IMU device for velocity-based training (VBT), as certain measurements (e.g., CMV, CPV) do not possess practically acceptable reliability or accuracy. Finally, the IMU device exhibited considerable practical data collection concerns, as one participant was completely excluded and 13% of the remaining attempts displayed obvious internal error.

Perception of changes in bar velocity in resistance training: Accuracy levels within and between exercises

Velocity-based training is a method used to monitor resistance-training programs based on repetition velocities measured with tracking devices. Since velocity measuring devices can be expensive and impractical, trainee's perception of changes in velocity (PCV) may be used as a possible substitute. Here, 20 resistance-trained males first completed 1 Repetition Maximum (RM) tests in the bench-press and squat. Then, in three counterbalanced sessions, participants completed four sets of eight repetitions in both exercises using 60%1RM (two-sessions) or 70%1RM. Starting from the second repetition, participants reported their PCV of each repetition as a percentage of the first repetition. Accuracy of PCV was calculated as the difference between PCV and actual changes in velocity measured with a linear-encoder. Three key findings emerged. First, the absolute error in the bench-press and squat was ≈5.8 percentage-points in the second repetition, and increased to 13.2 and 16.7 percentage-points, respectively, by the eighth repetition. Second, participants reduced the absolute error in the second 60%1RM session compared to the first by ≈1.7 in both exercises (p ≤ 0.007). Third, participants were 4.2 times more likely to underestimate changes velocity in the squat compared to the bench-press. The gradual increments in the absolute error suggest that PCV may be better suited for sets of fewer repetitions (e.g., 4-5) and wider velocity-loss threshold ranges (e.g., 5-10%). The reduced absolute error in the second 60%1RM session suggests that PCV accuracy can be improved with practice. The systematic underestimation error in the squat suggests that a correction factor may increase PCV accuracy in this exercise.

Reliability of technologies to measure the barbell velocity: Implications for monitoring resistance training

This study investigated the inter- and intra-device agreement of four new devices marketed for barbell velocity measurement. Mean, mean propulsive and peak velocity outcomes were obtained for bench press and full squat exercises along the whole load-velocity spectrum (from light to heavy loads). Measurements were simultaneously registered by two linear velocity transducers T-Force, two linear position transducers Speed4Lifts, two smartphone video-based systems My Lift, and one 3D motion analysis system STT. Calculations included infraclass correlation coefficient (ICC), Bland-Altman Limits of Agreement (LoA), standard error of measurement (SEM), smallest detectable change (SDC) and maximum errors (MaxError). Results were reported in absolute (m/s) and relative terms (%1RM). Three velocity segments were differentiated according to the velocity-load relationships for each exercise: heavy (≥ 80% 1RM), medium (50% < 1RM < 80%) and light loads (≤ 50% 1RM). Criteria for acceptable reliability were ICC > 0.990 and SDC < 0.07 m/s (~5% 1RM). The T-Force device shown the best intra-device agreement (SDC = 0.01–0.02 m/s, LoA <0.01m/s, MaxError = 1.3–2.2%1RM). The Speed4Lifts and STT were found as highly reliable, especially against lifting velocities ≤1.0 m/s (Speed4Lifts, SDC = 0.01–0.05 m/s; STT, SDC = 0.02–0.04 m/s), whereas the My Lift app showed the worst results with errors well above the acceptable levels (SDC = 0.26–0.34 m/s, MaxError = 18.9–24.8%1RM). T-Force stands as the preferable option to assess barbell velocity and to identify technical errors of measurement for emerging monitoring technologies. Both the Speed4Lifts and STT are fine alternatives to T-Force for measuring velocity against high-medium loads (velocities ≤ 1.0 m/s), while the excessive errors of the newly updated My Lift app advise against the use of this tool for velocity-based resistance training.