ECSS Paris 2023: OP-AP07
INTRODUCTION: Professional boxing is a dynamic combat sport, whereby two competitors exchange punches. A boxing punch is a complex action involving biomechanical and neuromuscular elements, with end range impact resulting from enhanced peak force (PF), impulse, and rate of force development (RFD). Despite similar upper body movement patterns, traditional strength assessments such as the dynamic bench press one repetition maximum are not positively associated with punch impact outcomes, as this does not accurately reflect punching kinetics or kinematics, likely due to the ‘sticking point’ early in the concentric phase of the motion. To that end, isometric testing assessments potentially offer a more valuable insight into examining end range PF, impulse and RFD at various boxing punch specific joint angles. Therefore, this study aimed to evaluate the intra and inter session reliability of a novel isometric bench press (ISOBP) protocol on force-time characteristics in elite professional boxing athletes. METHODS: Following a standardised warm-up, ten professional boxers completed the ISOBP three times within sessions, conducted across one familiarisation and two main trials each separated by a period of 48 hours. The ISOBP was conducted within an adjustable isometric rig, at 105° and 145° boxing punch specific joint angles, confirmed by a hand-held 360-degree goniometer. A padded bench was placed over two calibrated force plates to capture PF, impulse, and RFD variables. Multiple intraclass correlation coefficient (ICC) analyses utilising average measure two-way mixed and absolute agreement parameters, alongside typical error and coefficients of variation (CVs) to determine the magnitude of measurement error (≤10% classified as acceptable) were used to assess intra and inter session reliability. RESULTS: Intra session reliability was good to excellent for PF, force at specific intervals, absolute impulse, and longer-epoch RFD measures (ICCs = 0.86-0.99; CVs = 2.0-9.3) at both angles. Inter session reliability was also good to excellent for PF and absolute impulse <100ms at 105° (ICCs = 0.89-0.96; CVs = 3.6-4.3). However, reliability was poor for all RFD, most net force and impulse outcomes, and shorter-epoch measures. CONCLUSION: The ISOBP demonstrated reliable intra session measurement of PF, interval-specific force, absolute impulse, and longer-epoch RFD, making it useful for evaluating strength training effectiveness and setting performance benchmarks. However, for longitudinal monitoring only inter session PF and impulse <100ms in the 105° ISOBP were reliable, so other variables should be interpreted with caution. For outcome metrics with poor inter session reliability, standardisation of protocol conditions, testing frequency and incorporating additional measures of neuromuscular function are critical to provide a more global view of an athlete’s capacity or progress. This approach, along with the use of typical error scores, ensures that observed changes reflect actual improvements alternate to natural variability in performance.
Read CV Carl Langan-EvansECSS Paris 2023: OP-AP07
INTRODUCTION: In boxing, force and velocity of punches are discriminating performance parameters (Lenetsky et al., 2018; Loturco et al., 2016). A recent study has validated a force-velocity-power (FVP) profile for a landmine punch exercise (LPE), having technical similarities with a boxing punch which could be helpful for a simple training monitoring (Gusciglio & Morin, 2023). However, the FVP profiles parameters obtained (F0, V0 and Pmax) were not analyzed in relation to punches force and velocity, which was the objective of this study. METHODS: 27 experimented boxers (23.9± 4.4 years old, 75.8± 10.2kg) performed LPE with a 10kg bar consisting in 2 sets of 4 repetitions with an additional load corresponding to 20% and 50% of their body mass (Gusciglio & Morin, 2023). An accelerometer (Delsys, USA, 500Hz) was fixed to the bar to record its acceleration and determine its linear velocity. Theorical mechanical parameters of FVP were calculated using a custom-made spreadsheet (F0, V0, and Pmax). Participants also performed 6 rear cross and hook punches with maximal intensity and their habitual technique on a 3D force plate (AMTI, USA, 2000Hz) fixed to a vertical support and covered by a body shield. A kinematic marker was placed on the rear arm glove at the 1st metacarpal level to registered punches 3D velocity (Qualysis, Sweden, 200Hz). Maximal punches velocity and force impulse were determined. Pearson’s correlations were made to investigate the relationship between these variables and FVP theorical parameters. Fisher’s z was calculated to determine the effect size. RESULTS: LPE F0 (10.6 ± 1.5 N/kg) was significantly correlated with cross (51.7± 10.9N.s; r²=0.29; ES=0.61; p<0.01) and hook force impulses (41.4± 14.8N.s; r²=0.33; ES=0.65; p<0.01). LPE V0 (3.2± 0.42m/s) was significantly correlated with hook velocity (14.5± 1.3m/s; r²=0.2; ES=0.48; p=0.02) but not with cross velocity (9.9± 0.6m/s; r²=0.15; p=0.051). LPE Pmax (8.6± 1.6 W/kg) was also significantly correlated with cross (r²=0.22; ES=0.51; p=0.02) and hook force impulse (r²=0.24; ES=0.53; p=0.01) but only with cross velocity (r²=0.28; ES=0.60; p<0.01). CONCLUSION: F0 and Pmax of LPE are significantly correlated with the impulse of rear hook and cross punches but V0 was only significantly correlated to cross velocity. Thus, LPE seems to be an effective, fast and low-cost tool to help monitoring the force and power development of boxers. Nonetheless, the moderate correlation magnitudes should be considered and could be influenced by the movements’ technical differences, where LPE requires a higher vertical component. It might be interesting to develop a FVP profile on a movement simulating a punch with different loads attached to a pulley and replicate this study. REFERENCES: 1. Lenetsky et al (2018), Journal of Strength and Conditioning Research. 2. Loturco et al (2016), Journal of Strength and Conditioning Research. 3. Gusciglio & Morin (2023), International Journal of Strength and Conditioning.
Read CV Frederic SIMONECSS Paris 2023: OP-AP07
INTRODUCTION: Rapid weight loss (RWL) is a common strategy among combat sports athletes [1]. While previous studies have explored the impact of RWL on strength, endurance, and decision-making [2], its relationship with specific performance variables remains unclear. Therefore, this study investigated the correlation between RWL and key performance indicators in judo. METHODS: Thirty-three judo athletes (age: 21.0 ± 2.2 years; judo grade: 1st dan) competing at national and international levels were monitored during an official competition. Body mass (BM) was recorded 10, 7, and 3 days before the weigh-in, on the day of the weigh-in, and competition day using a Tanita BC-558 scale with a precision of 0.1 kg. The BM reduction was calculated from seven days before the weigh-in to the official weigh-in. Performance metrics were assessed as follows: winning rate - the ratio of matches won to total matches competed; number of attacks per match - the total number of attacks divided by the total matches performed; technical variability - attack diversity, considering different attack sides and directions; and scoring index - the total points scored divided by the total number of attacks, reflecting scoring efficiency. Pearson correlation analyses were conducted to assess the relationship between the magnitude of RWL and performance variables, whereas logistic regression was used to analyze the association between BM reduction and medal success. A significance level of p < 0.05 was applied. RESULTS: BM reduction over the seven days before weigh-in (4.1 ± 1.6%; 3.9 ± 1.5 kg) showed no significant correlation with winning rate (r = 0.015, 95%CI: -0.33, 0.36, p = 0.935), number of attacks per match (r = 0.012, 95%CI: -0.33, 0.35, p = 0.947), nor technical variability (r = -0.077, 95%CI: -0.41, 0.27, p = 0.669). However, a significant negative correlation was observed between BM reduction and the scoring index (r = -0.392, 95%CI: -0.65, -0.07, p = 0.024). Additionally, a greater BM reduction during the analyzed period increased the likelihood of winning a medal (OR = 1.63; 95%CI: 1.04, 2.56; p = 0.033). CONCLUSION: Although BM reduction over the seven days before weigh-in did not significantly influence the winning rate, number of attacks, or technical variability, it was negatively associated with the scoring index. This finding suggests that greater BM reduction may impair scoring efficiency. Moreover, logistic regression indicated that greater BM reduction over ten days increased the odds of winning a medal. Funding: FAPESP – Grants 2024/18847-4 and 2024/08930-1; CNPq – Grants 403032/2023-7 and 305507/2023-0. [1] Artioli et al. (2010) Med Sci Sports Exerc. 42(3), 436-442; [2] Dos Santos et al., (2024), Phys Act Nutr. 28(3).
Read CV Emerson FranchiniECSS Paris 2023: OP-AP07