A 5-Year Analysis of Age, Stature and Armspan in Mixed Martial Arts

Purpose: Athlete stature and armspan is anecdotally assumed to provide an advantage in mixed martial arts (MMA), despite an absence of supporting data. In contrast, winners of MMA bouts have been shown to be younger than bouts losers. Whilst absolute measurements of stature, armspan and armspan:stature scale (A:S) have been shown to not distinguish between winners and losers of MMA bouts, relative differences between competitors have not been analysed. This study aimed to analyse 5 years of athlete age and morphological data to replicate and expand previous studies to determine whether absolute and/or relative age and morphological variables effect winning and losing in MMA. Methods and Results: Bayes factor (BF>3) inferential analyses conducted on the cohort overall (n = 2,229 professional bouts), each year sampled and each individual body mass division found that only absolute (winners = 29.8 ± 4 years; losers = 30.7 ± 4.2 years) and relative age (winners = 0.82 ± 5.3 years younger than losers) differentiates between winners and losers across the whole cohort, in 4 of the 5 years, and in 4 of the 13 divisions sampled. Armspan appears to provide an advantage in heavyweight only (winners = 198.4 ± 6.6cm; losers = 196.1 ± 7.7cm), with greater A:S being a disadvantage (winners = 1.003 ± 0.022cm∙cm-1; losers = 1.010 ± 0.023 cm∙cm-1) in women's strawweight only. No variables had any effect on how bouts were won. Conclusions: These results confirm previous reports that the effect of athlete morphology is greatly overstated in MMA, appearing to be irrelevant in most divisions. Bout winners tend to be younger than losers, particularly in divisions displaying more diverse skill requirements.

Verbal instructions affect reactive strength index modified and time-series waveforms in basketball players

This study aimed to determine the effects of different verbal instructions, intended to affect the countermovement jump (CMJ) execution time, on the reactive strength index modified (RSIMod) and the time-series waveforms. Thirteen male basketball players performed six CMJs on a force plate with two different verbal instructions: 'jump as high as possible' (CMJhigh) and 'jump as high and as fast as possible' (CMJfast). Force-, power-, velocity-, and displacement-series waveforms, RSIMod and jump height were compared between conditions using statistical parametric mapping procedures. CMJfast showed greater values in RSIMod (p = 0.002) despite no differences in jump height (p = 0.345). Unweighting force (between 18% and 33% of total time) was lower in the CMJfast compared to CMJhigh. Larger force (between 53% and 63% of total time), velocity (between 31% and 48% of total time) and power (between 43% and 56% of total time) were found in the CMJfast compared to CMJhigh. These findings suggest that commanding athletes to jump as high and fast as possible increases rapid force production. Additionally, the results highlight the relevance of the countermovement phase in jumping and show that RSIMod could increase without power output modifications during propulsion, despite previous studies having reported positive associations between RSIMod propulsion power.

CORE TRAINING IN MARTIAL ARTS ATHLETES

ABSTRACT Introduction: Martial arts comprise skill-based fighting games whose early specialized training is essential for development. Martial arts techniques are based on body movements requiring physical coordination, body stability, and endurance. Objective: Design a specific training for the abdominal center in martial arts athletes. Methods: Twelve martial arts athletes were selected as research subjects. These athletes were submitted to experimental training for six semesters. According to the characteristics of movement and effort, this paper evaluates the capacity of athletes’ abdominal center muscle groups. The content of the experimental training included stability, strength, explosiveness, and endurance. The experimental results were analyzed based on current scientific literature and mathematical statistics. Results: Compared to the test before the experiment, the stabilization strength of the abdominal core muscles in routine training was unchanged without statistical significance (P>0.05). After six weeks of experimental core strength training, core muscle stability strength was significantly increased (P<0.001). Conclusion: The abdominal core stability of martial arts athletes was improved by experience. Its positive performance was in martial arts athletes’ stability, strength, explosive power, and endurance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Acute effects of ballistic versus heavy-resistance exercises on countermovement jump and rear-hand straight punch performance in amateur boxers

Background

Ballistic and heavy-resistance exercises may potentially enhance lower body power, which is paramount for the punching performance of amateur boxers. This study aimed to determine the acute effects of ballistic exercise (BE) and heavy-resistance exercise (HRE) on countermovement jump (CMJ) and rear-hand straight punch performance in amateur boxers.

Methods

Ten amateur boxers performed two conditioning exercises in a randomized and counterbalanced order as follows: squat jump with 4 sets × 8 repetitions at 30% one-repetition maximum (1RM) for BE and squat with 3 sets × 5 repetitions at 80% 1RM for HRE. The jump height (JH), relative maximal force (RMF), relative maximal power (RMP) of the CMJ, punch force (PF), and punch speed (PS) of a rear-hand straight punch were measured before and 3, 6, 9, and 12 min after either BE or HRE.

Results

No significant condition × time interaction was found for JH (p = 0.303), RMF (p = 0.875), RMP (p = 0.480), PF (p = 0.939), and PS (p = 0.939). In addition, no main effect of the condition for JH (p = 0.924), RMF (p = 0.750), RMP (p = 0.631), PF (p = 0.678), and PS (p = 0.712). A significant main effect of time was observed for PF (p = 0.001) and PS (p = 0.001), whereas JH (p = 0.081), RMF (p = 0.141), and RMP (p = 0.430) were not. Pairwise comparison identified that PF (p = 0.031) and PS (p = 0.005) significantly increased at 9 min compared with those at baseline.

Conclusions

The findings of this study demonstrated that BE and HRE protocols can potentiate the rear-hand straight punch performance at 9 min but bring less favorable improvements for JH, RMF, or RMP of CMJ.

Differences in Force-Velocity Profiles During Countermovement Jump and Flywheel Squats and Associations With a Different Change of Direction Tests in Elite Karatekas

The force-velocity (F-v) relationship has been proposed as a biomechanical characteristic to comprehensively evaluate neuromuscular capabilities within different tasks such as vertical jumping, sprinting and bench pressing. F-v relationship during flywheel (FW) squats was already validated, however, it was never compared to F-v profile of vertical jumps or associated with change of direction (CoD) performance. The aims of our study were (1) to compare F-v profiles measured during counter movement jumps (CMJs) and FW squats, (2) to determine correlations of F-v mechanical capacities with different CoD tests, (3) to investigate the portion of explained variance in CoD tests with the F-v outcome measures. A cross-sectional study was conducted on 39 elite karatekas. They performed CMJs and FW squats using progressive loads to calculate F-v profile outcome variables and different CoD tests (CoD at 90°, CoD at 180°, t-test, short karate specific test (KST) and long KST). Our results showed significantly higher values in all F-v outcome variables (F₀—theoretical maximal force, V₀—maximal unloaded velocity, P_max—maximal power output, F-v_slope—the slope of F-v relationship) calculated from CMJs compared to FW squats (all p < 0.01). Significant positive moderate correlations between the tasks were found for F₀ and P_max (r = 0.323–0.378, p = 0.018–0.045). In comparison to F-v outcome variables obtained in FW squats, higher correlations were found between F-v outcome variables calculated from CMJs and CoD tests. The only significant correlation in F-v outcome variables calculated from FW squats was found between P_max and short KST time. For all CoD tests, only one F-v predictor was included; more specifically—CMJ-F₀ for CoD 90°, CoD 180° and t-test, and FW-P_max for short KST performance. To conclude, our results showed that F-v relationship between CMJs and FW squats differed significantly and cannot be used interchangeably for F-v profiling. Moreover, we confirmed that high force and power production is important for the successful performance of general and karate specific CoD tasks.

Exploratory Systematic Review of Mixed Martial Arts: An Overview of Performance of Importance Factors with over 20,000 Athletes

This review aimed to analyze the findings in the literature related to Mixed Martial Arts (MMA) through an exploratory systematic review and to present the state of the art from a multifactorial perspective. The review was conducted in accordance with the PRISMA statement, with a search performed in the Scopus, PubMed, and Web of Science databases. Participants were competitive athletes (amateurs or professionals) of regional, national, or international levels. Of the 2763 registries identified, 112 studies met the eligibility criteria. The pooled sample size and age were 20,784 participants, with a mean age of 27.7 ± 6 years for male and 28.9 ± 3 years for female, with the vast majority of athletes being male (94.9%). MMA athletes were 17.2% amateurs, 73.8% professionals, and 9% were not reported. The scientific literature related to MMA reported injuries (n = 28), weight loss (n = 21), technical and tactical analysis (n = 23), physical fitness (n = 8), physiological responses and training characteristics (n = 13), psychobiological parameters (n = 12), and interventions applied to MMA athletes (n = 7). Therefore, this exploratory systematic review presents practitioners and researchers with seven broad summaries of each facet of performance of importance in this population of athletes.

Reactive strength index-modified: reliability, between group comparison, and relationship between its associated variables

To investigate and compare the reliability of reactive strength index-modified (RSImod) and its associated variables (jump height [JH] and [time to take-off]) 20 combat fighters and 18 physically active men participated in this study. They visited the laboratory three times; firstly, for jump familiarization and two sessions for test-retest (2-7 days apart). For both groups, the between-day changes in performance were trivial to small (≤ 1.1%). The coefficient of variation (CV) comparisons (i.e. CV ratio) demonstrated that combat athletes had a lower test-retest variation for RSImod (0.87) and JH (0.80) than non-athletes. Combat athletes demonstrated a greater JH than physically active men (0.43 vs 0.37; p = 0.03, g = 0.73), but small and non-significant differences were observed for RSImod (0.60 vs 0.55; p = 0.24, g = 0.38) and TTT (0.70 vs 0.72; p = 0.32, g = 0.33). RSImod was more positively correlated with JH (r = 0.75-0.87; p < 0.001) than negatively correlated with TTT (r = 0.45-0.54; p < 0.001). This study suggests that RSImod is a reliable variable obtained during CMJ testing in combat athletes and physically active men, with scores being slightly better for combat athletes. In terms of performance, combat athletes jumped higher than physically active men, but no differences in RSImod or TTT were observed. Lastly, RSImod was more strongly related to JH than TTT, and this was more evident in athletes than nonathletes. This indicates that the combat athletes were able to better utilize their (equal) time spent jumping (higher), possibly via greater utilization of the stretch shortening cycle, faster or more optimal motor unit recruitment, or an array of other factors.

The relationship between vertical stiffness during bilateral and unilateral hopping tests performed with different strategies and vertical jump performances

Vertical stiffness has been highlighted as a potential determinant of performance and may be estimated across a range of different performance tasks. The aim of the current study was to investigate the relationship between vertical stiffness determined during 9 different hopping tests and performance of vertical jumps. Twenty healthy, active males performed vertical hopping tests with three different strategies (self-selected, maximal, and controlled) and three different limb configurations (bilateral, unilateral preferred, and unilateral non-preferred), resulting in nine different variations, during which vertical stiffness was determined. In addition, participants performed squat jump (SQJ) and countermovement jump (CMJ) during which jump height, CMJ stiffness, and eccentric utilization ratio (EUR) were determined. Vertical stiffness in bilateral and unilateral preferred tasks performed with a self-selected and maximal, but not controlled, strategy was associated with stiffness in the CMJ (r = 0.61-0.64; p < 0.05). However, stiffness obtained during unilateral preferred and non-preferred hopping with self-selected strategy was negatively associated with performance in SQJ and CMJ tasks (r = -0.50 to -0.57; p < 0.05). These findings suggest that high levels of vertical stiffness may be disadvantageous to static vertical jumping performance. In addition, unilateral hopping with a self-selected strategy may be the most appropriate task variation if seeking to determine relationships with vertical jumping performance. HighlightsStiffness obtained during unilateral hopping with a preferred strategy was negatively associated with vertical jumping performancesStiffness obtained during hopping with preferred and maximal strategies was associated with stiffness obtained during a countermovement jumpIn this population, hopping stiffness may therefore be reflective of an individual's countermovement jump strategyHigh levels of stiffness may be disadvantageous to static-start vertical jumping.

The Deceleration Deficit: A Novel Field-Based Method to Quantify Deceleration During Change of Direction Performance

Clarke, R, Read, PJ, De Ste Croix, MBA, and Hughes, JD. The deceleration deficit: a novel field-based method to quantify deceleration during change of direction performance. J Strength Cond Res XX(X): 000-000, 2020-The study investigated the relationship between linear and change of direction (COD) speed performance components and the individual differences between deceleration deficit (DD) and COD deficit (CODD). Thirty-six subjects (mean ± SD: age = 20.3 ± 2.9 years; stature = 175.2 ± 7.7 cm; and body mass = 78.0 ± 16.7 kg) completed 3 trials of a 505 test in both turning directions (dominant [D]; nondominant [ND]) and 3 15-m linear sprints. Deceleration deficit was calculated by the 15-m approach in the 505 test, minus the athlete's linear 15-m sprint time. To compare individuals CODD and DD, z-scores were calculated, and moderate worthwhile changes (MWCs) were identified between these deficit z-scores. Significant correlations were identified between linear sprints and 505 time (D: r = 0.71, 0.74; P < 0.01. ND: r = 0.76, 0.75; P < 0.01) for 10-m and 15-m sprint. respectively, and between 505 performance and CODD (D: r = 0.74; P < 0.01. ND: r = 0.77; P < 0.01) and DD (D: r = 0.41, P < 0.05. ND: r = 0.44, P < 0.01). Deceleration deficit was significantly related to CODD (D: r = 0.59; P < 0.01. ND: r = 0.62; P < 0.01); however, 78% of subjects demonstrated differences between these deficit measures greater than an MWC. In conclusion, linear speed has the strongest significant relationship with 505 performance. Deceleration deficit could provide a more isolated construct than CODD which may be related to an athlete's deceleration capabilities.