ABSTRACT:Doyle, BP, Stanelle, ST, Riechman, SE, and Mann, JB. The NFL scouting combine explains within-position physical performance variance but is a poor predictor of draft outcomes. J Strength Cond Res XX(X): 000-000, 2026-This study evaluates the National Football League (NFL) Combine's physical performance tests ability to (a) explain performance variance between players of similar positions and (b) predict draft status. Players who completed all combine assessments (n = 3,681) were grouped by position group as quarterbacks, skill (SK), linemen (BIG), and mid-size. Variables included the 6 NFL Combine tests, height, body mass, maximal anaerobic power, and momentum for speed and change-of-direction (COD) tests. Principal component analysis with promax rotation and parallel analysis reduced data dimensionality for each position group. Binary logistic regression with Monte Carlo simulated cross-validation (n = 1,000) examined the impact of identified physical performance components on draft likelihood for each position group. Multivariate analysis of variance with post-hoc testing compared drafted vs. undrafted players' component scores. Four physical performance components explaining meaningful variance were identified: momentum (26.5-36.1% explained), power (22.1-29.5% explained), COD (15.5-19.7% explained), and strength (10.0-11.5% explained; BIG and SK only). Logistic regression indicated that few components significantly influenced draft probability (p < 0.05; SK only). Overall model predictive performance was poor (receiver operator characteristic area under the curve < 0.75). Differences between drafted and undrafted players were found in wide receivers (WR) (power, COD, strength), defensive backs (momentum, strength), and running backs (strength), with undrafted players having unexpectedly superior performance component scores than drafted players across several performance qualities (small-to-moderate effect, p < 0.05). These results suggest that physical performance alone does not account for most variance in draft status once underlying performance thresholds are met. National Football League Combine tests inconsistently predicted draft outcomes but may still guide roster decisions when contextualized as underlying physical performance attributes to highlight individual deficits to evaluate an athlete's fit for team-specific demands.

Objective: This study aimed to characterize trends in body roundness index (BRI) among first responders and examine differences in health and fitness across BRI-based quartiles. Methods: Archival data from 158 first responders—97 firefighters and 61 law enforcement officers (LEOs)—were analyzed. Results: Differences were observed in body composition and physical performance parameters, with the first quartile (Q1) BRI group exhibiting the most favorable profiles. These differences remained after adjusting for age, especially compared with the Q4 group. Blood biomarkers showed minimal differences, with a trend toward lower fasting blood glucose in Q1. Firefighters showed poorer health indices but higher fitness than law enforcement officers, consistent with past research. Conclusions: BRI is a useful, potentially cost-effective tool for first responders to assess health and wellness annually and quarterly without clinical equipment.

Velocity zones (e.g., 1.0-0.75 m·s-1) are commonly aligned with terminology such as "starting strength", 'speed-strength', 'strength-speed', 'accelerative strength', or 'absolute strength'. However, the load-velocity profiles of most exercises do not align with these discrete bands. The aims of this study were to 1) develop load-velocity profiles of seven weightlifting derivatives; and 2) create exercise-specific velocity zones that can be used to guide training prescription. Fourteen (6 males and 8 females) weightlifting athletes undertook six testing sessions that required maximal strength testing on occasions one and two, and the development of load-velocity profiles for the power snatch, hang power clean, snatch pull, hang clean pull, hang power snatch, clean pull, and hang snatch pull on testing occasions three to six. During each testing occasion, peak velocity was assessed. Linear mixed models with effect size ±95% confidence limits (CL) were used to detect changes across profiles and estimate exercise specific velocity zones. While all load-velocity profiles had a clear reduction in velocity as load was increased, each exercise was found to have substantially different velocity zones when compared to previous recommendations. Of note, all 'absolute strength' zones (i.e., > 80% one repetition maximum) from the weightlifting derivatives were found to be greater than 1.3 m·s-1 which is commonly used as the threshold for 'starting strength'. These findings demonstrate that, if these terms are to be used, exercise-specific load-velocity profiles should be developed. Furthermore, these findings provide practitioners with exercise-specific zones that can be used to enhance training prescription and target specific strength qualities.

Mann, JB, Cowley, N, and Weakley, J. The role of speed, change of direction, and momentum by position and starting status in Division 1 collegiate football players. J Strength Cond Res 39(1): 41-47, 2025-This study (a) investigated differences between big, mid, and skill positions in sprint and change of direction times and momentum; (b) compared starting and nonstarting athletes; and (c) investigated whether thresholds can be developed to distinguish between starting and nonstarting Division 1 collegiate football athletes. Data from 496 collegiate football players who completed the 40-yard dash, pro-agility, and L drill were analyzed. Momentum was calculated using body mass and the average velocity during each test. To assess differences between positions and starters and nonstarters, data were analyzed using linear mixed models with effect size +/- 95% confidence intervals. Receiver operating characteristic (ROC) curves were generated to determine whether a cutoff value could be used to distinguish starters from nonstarters. Significant differences for both time and momentum were found between positional groups and starters and nonstarters for all tests in all positions. Starting skill position players tended to have greater differences in sprint or change of direction times and starting big players had greater sprint momentum. However, it should be noted that all ROC curves demonstrated relatively poor predictive value. Collectively, these findings demonstrate that bigger, faster players are preferentially selected in collegiate Division 1 football and there may be value in coaches collecting and assessing different outcome measures (e.g., sprint times and sprint momentum) depending on the positional group of the player. Finally, it should be acknowledged that setting binary thresholds to guide selection decisions is ill-advised and that speed, change of direction, and momentum are only one piece of the performance puzzle.

The aims of this study were to: 1) detail the strength, power, speed, and body mass (i.e. physical qualities) of National Collegiate Athletic Association (NCAA) Division 1 American football players by playing position across a four-year collegiate career, and 2) quantify the rate of change in physical qualities as athletes progress through their eligibility period. 2628 observations from 512 NCAA Division 1 American football players were collected during a standardised testing battery that took place across a 15-year period. One-repetition maximum bench press and back squat, 40-yard sprint, vertical jump, standing broad jump, and body mass were analyzed. Year-on-year changes in physical characteristics by the entire cohort and positional groups were analyzed using linear mixed models with Cohen's effect size (ES) +/- 95% confidence intervals (CI). Improvements in physical qualities occurred over the four years, although the largest changes were evident in the first year, with the improvements becoming less pronounced each year. For example, across the cohort, large effects in the bench press (ES +/- 95%CI: 1.63 +/- 0.18) and back squat (ES +/- 95%CI: 1.62 +/- 0.18) occurred in the first year but only small changes occurred between years 3 and 4 (ES +/- 95%CI: 0.45 +/- 0.16 and 0.26 +/- 0.16, respectively). Collectively, this study demonstrates the longitudinal changes in strength, power, speed, and body mass of collegiate Division 1 American football players across different positional groups. Furthermore, it shows that physical qualities improve throughout the four years, but the year-on-year change becomes smaller each year and therefore suggests physical qualities become harder to increase/improve.

The snatch is prevalent in competitive and recreational lifting as well as strength training. Lifting straps (LS) are an accessory that wrap around the hand and the barbell, reducing the limitations of grip strength. However, this benefit has not been quantitatively supported for the snatch. The aim of this study was to compare muscle activation patterns between using LS and not using them at 80% of the snatch one-repetition maximum in a group of twelve sub-elite male weightlifters. It was hypothesized that LS would decrease forearm muscle activation and increase larger muscle group activation. Eight dominant-side muscles located in the lower limbs, back, shoulders, and upper limbs were measured via electromyography. A two-way analysis of variance (ANOVA), followed by a Tukey Pairwise comparison, revealed that LS significantly impacted (p = 0.039) muscle activation in the snatch. Specifically, latissimus dorsi activation increased the most (17.2 +/- 55.7%), while biceps brachii activation decreased the most (-8.0 +/- 37.0%). Comparing muscle activation across different phases of the lift showed that LS decreased forearm and bicep brachii activation by 16.0 +/- 25.2% and 7.1 +/- 35.7% respectively during the pull phase, and increased vastus lateralis, latissimus dorsi, and medial deltoid activation between the second part of the first pull and the catching position, with a corrected effect size exceeding 1.5. These results support the hypothesis that LS decrease forearm activation, which could reduce grip strength limitations and consequently, reduce problems associated with fatigue. Increases in vastus lateralis activation with the use of LS suggest a greater training stimulus during the snatch, which can help develop leg strength.

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.

Change of direction, stops, and pivots are among the most common non-contact movements associated with anterior cruciate ligament (ACL) injuries in soccer. By observing these dynamic movements, clinicians recognize abnormal kinematic patterns that contribute to ACL tears such as increased knee valgus or reduced knee flexion. Different motions and physical demands are observed across playing positions, which may result in varied lower limb kinematic patterns. In the present study, 28 college and sub-elite soccer players performed four dynamic motions (change of direction with and without ball, header, and instep kick) with the goal of examining the effect of on-field positioning, leg dominance, and gender in lower body kinematics. Motion capture software monitored joint angles in the knee, hip, and ankle. A three-way ANOVA showed significant differences in each category. Remarkably, centrally positioned players displayed significantly greater knee adduction (5° difference, p = 0.013), hip flexion (9° difference, p = 0.034), hip adduction (7° difference, p = 0.016), and dorsiflexion (12° difference, p = 0.022) when performing the instep kick in comparison to their laterally positioned counterparts. These findings suggest that central players tend to exhibit a greater range of motion when performing an instep kicking task compared to laterally positioned players. At a competitive level, this discrepancy could potentially lead to differences in lower limb muscle development among on-field positions. Accordingly, it is suggested to implement position-specific prevention programs to address these asymmetries in lower limb kinematics, which can help mitigate dangerous kinematic patterns and consequently reduce the risk of ACL injury in soccer players.

Hamstring injuries (HSIs) are prevalent in sports that involve changes in direction, kicking, and sprinting. These injuries are a major cause of time lost from competition, practice, and training, as well as increased healthcare costs. In a Division I collegiate football program, the authors implemented a multifactorial approach that included repeated performance assessments, detailed data analysis, and a flexible strength and conditioning regimen. Over a three-year period, this resulted in no game time loss due to HSI. This model can be adapted and implemented across sports settings.

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.

The use of weightlifting exercises is prevalent in competitive and recreational environments, as well as sport-specific training. Traditionally, weightlifting coaches prescribe specific training loads based on an individual's maximal ability. Velocity-based training offers an alternative method that promises to quantify strength based on velocity and provides information that increases competitiveness through real-time feedback. Various velocity measurement devices are available on the market. Their precision is critical for the adequate implementation of velocity-based training. The aim of the present study was to compare the concentric peak velocity measurements of five of these devices during two weightlifting movements, the snatch and clean, to data collected with a 12-camera motion capture system, which was considered as gold standard. It was hypothesized that the velocity measurement devices used in this study would vary in accuracy based on their retail prices. Velocity readings associated with light and moderate (40% and 70% of one-repetition max) loads were measured for both the snatch and clean performed by 12 competitive weightlifters. A least products regression was used to assess validity by comparing five devices against a criterion measure. A general linear model showed statistical differences in the velocities measured with these five devices (p < 0.001). Specifically, the GymAware RS linear position transducer was the most accurate device, demonstrating no fixed or proportional bias when used to quantify velocity during the snatch and clean. The remaining four devices significantly underestimated peak velocity, which would directly impact the daily planning of lifters' training. Practitioners must consider the error and bias of each device before implementing velocity-based training.

Lopes dos Santos, M, Mann, JB, Berton, R, Alvar, B, Lockie, RG, and Dawes, JJ. Using the load-velocity profile for predicting the 1RM of the hexagonal barbell deadlift exercise. J Strength Cond Res 37(1): 220-223, 2023-The aim of this study was to determine whether bar velocity can be used to estimate the 1 repetition maximum (1RM) on the hexagonal bar deadlift (HBD). Twenty-two National Collegiate Athletic Association Division I male ice hockey players (age = 21.0 +/- 1.5 years, height = 182.9 +/- 7.3 cm, and body mass = 86.2 +/- 7.3 kg) completed a progressive loading test using the HBD at maximum intended velocity to determine their 1RM. The mean concentric velocity was measured for each load through a linear position transducer. The a priori alpha level of significance was set at p = 0.05. The mean concentric velocity showed a very strong relationship to %1RM (R2 = 0.85). A nonsignificant difference and a trivial effect size (ES) were observed between the actual and predicted 1RM (p = 0.90, ES = -0.08). Near-perfect correlations were also discovered between the actual and predicted 1RM (R = 0.93) with low typical error and coefficient of variation (5.11 kg and 2.53%, respectively). This study presented results that add the HBD to the list of exercises with established load-velocity relationships. The predictive ability for 1RM HBD indicates that this is a viable means of prediction of 1RM.

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.

Abstract Mann, JB, Mayhew, JL, Dos Santos, ML, Dawes, JJ, and Signorile, JF. Momentum, rather than velocity, is a more effective measure of improvements in Division IA football player performance. J Strength Cond Res 36(2): 551–557, 2022—Speed, or the time to complete straight runs or agility drills, is commonly used to assess performance in collegiate American football players. However, it is common for players' speeds to plateau by the second year of eligibility, whereas their body masses continue to increase. The purpose of this study was to track change in speed, body mass, and momentum (body mass · velocity), across Division 1 football players' 4-year careers (n = 512). Complete data were derived for the 40-yd sprint (n = 82), the proagility shuttle (n = 73), and the L drill (n = 73) from the same NCAA Division 1 team over a 15-year period. Significant changes were seen for velocity between year 1 and the next 3 playing years (p < 0.05), with no differences between years 2 and 4, whereas body mass increased significantly across all playing years (p < 0.05). Further momentum increased across all years for all tests (p < 0.0001). These results indicate the importance of including changes in body mass when evaluating performances during sprints and change of direction drills. Our results also suggest that using sprint or agility drill times to evaluate playing potential across football players' collegiate careers may be ineffective and can provide players with a false and disheartening picture of their improvements across their careers. Momentum, which incorporates training-induced increases in both speed and body mass, would be a more relevant and supportive measure of players' improvements. In addition, the simple computation of this variable, using existing speed and body mass data, may be an important addition to the National Football League combine as a measure of playing potential in the professional game.

ABSTRACT Velocity-based training (VBT) is a contemporary method of resistance training that enables accurate and objective prescription of resistance training intensities and volumes. This review provides an applied framework for the theory and application of VBT. Specifically, this review gives detail on how to: use velocity to provide objective feedback, estimate strength, develop load-velocity profiles for accurate load prescription, and how to use statistics to monitor velocity. Furthermore, a discussion on the use of velocity loss thresholds, different methods of VBT prescription, and how VBT can be implemented within traditional programming models and microcycles is provided.

In alignment with efforts to mitigate the negative health consequences of Parkinson's Disease (PD), the purpose of this investigation was to examine if participation in a community-based boxing program (CBP) was associated with improvements in balance and fall risk reduction among individuals with PD. In this retrospective cross-sectional study, de-identified data from 12 individuals with PD participating in a CBP was examined. Participants included those with a Hoehn and Yahr stage between 1 and 3, averaging 2.8 ± 0.8 CBP sessions per week for 6.1 ± 0.8 months between testing. Baseline and re-evaluation testing included the Fullerton Advanced Balance (FAB) Scale and Timed Up and Go (TUG) to quantify balance and fall risk. Sessions were 90-minutes in length involving a warm-up, boxing drills, strength and endurance exercises, and cool down. Sessions included multiple bouts of 30-60 second high-intensity exercise intervals (RPE between 15/20 to 17/20). Paired t-tests were used to determine if differences existed between the FAB and TUG from baseline to re-evaluation, with statistical significance accepted at p < 0.05 and > 0.8 interpreted as a large effect using Cohen's d. Results indicated a statistically significant increase and large effect in FAB performance, with a mean increase in score above previously reported minimal detectable change (MDC). While participation in CBP was associated with a statistically significant improvement and medium effect in the TUG, this did not demonstrate a population specific MDC. This study found that participation in a CBP was associated with improved balance among clients with PD.

This chapter provides some guidelines and framework, and dispel some myths about Velocity-Based Training (VBT). VBT is far from magical or mystical. It is a method of training where feedback of the velocity drives intrinsic motivation. The linear position transducer is a direct measurement of barbell velocity by measuring both distance and time. Camera-based systems utilise the distance travelled within their visual scope and divide by the frame rate as the time portion. Accelerometer-based units will utilise acceleration over their estimated bar path to derive velocity numbers. In team sports, the ability to actually implement a technique is paramount for its success. Velocity loss is another method of using VBT that does not matter if the utilisation is through a team or individualised approach. With velocity loss, there is a prescribed load for the day, and sets are terminated when the athlete loses a certain amount of velocity.