The Training of Medium- to Long-Distance Sprint Performance in Football Code Athletes: A Systematic Review and Meta-analysis

Pairwise Comparison of Heavy Dynamic Strength and Fast Dynamic Strength Interventions on Sprint Performance: A Systematic Review and Meta-Analysis

ABSTRACT

Pairwise comparison of heavy dynamic strength and fast dynamic strength interventions on sprint performance: a systematic review and meta-analysis. J Strength Cond Res 38(8): 1509-1520, 2024-Previous studies have shown that both heavy dynamic strength (HDS) and fast dynamic strength (FDS) training can be used to improve sprint performance; however, a review and meta-analysis investigating pairwise studies that compare these two training interventions have not been performed. The aims of the study were to systematically review and analyze HDS and FDS training methodologies and evaluate their effect size difference, in pairwise comparison studies to determine and compare their effects on sprint performance. Databases were systematically searched using Boolean phrasing to identify eligible articles, and meta-analyses were performed on the extracted data. Seven studies met the inclusion criteria, which resulted in data from 138 subjects across 24 separate sprint assessments. Overall, there was a small effect in favor of FDS (standardized mean difference = 0.27, 95% confidence intervals [-0.07; 0.60], 95% prediction intervals [-1.01; 1.55]), but this was deemed not significant because of the wide-ranging prediction intervals. There is no distinguishable difference between HDS and FDS training on sprint performance. The wide-ranging prediction intervals suggest the variability is too great to determine whether one training type is more effective than the other. Practitioners should consider the individual needs of their athletes when deciding which training type to use for long-term sprint development.

Dose-Response Modelling of Resistance Exercise Across Outcome Domains in Strength and Conditioning: A Meta-analysis

BACKGROUND

Resistance exercise is the most common training modality included within strength and conditioning (S&C) practice. Understanding dose-response relationships between resistance training and a range of outcomes relevant to physical and sporting performance is of primary importance for quality S&C prescription.

OBJECTIVES

The aim of this meta-analysis was to use contemporary modelling techniques to investigate resistance-only and resistance-dominant training interventions, and explore relationships between training variables (frequency, volume, intensity), participant characteristics (training status, sex), and improvements across a range of outcome domains including maximum strength, power, vertical jump, change of direction, and sprinting performance.

METHODS

Data were obtained from a database of training studies conducted between 1962 and 2018, which comprised healthy trained or untrained adults engaged in resistance-only or resistance-dominant interventions. Studies were not required to include a control group. Standardized mean difference effect sizes were calculated and interventions categorized according to a range of training variables describing frequency (number of sessions per week), volume (number of sets and repetitions performed), overall intensity (intensity of effort and load, categorised as low, medium or high), and intensity of load (represented as % of one-repetition maximum [1RM] prescribed). Contemporary modelling techniques including Bayesian mixed-effects meta-analytic models were fitted to investigate linear and non-linear dose-responses with models compared based on predictive accuracy.

RESULTS

Data from a total of 295 studies comprising 535 groups and 6,710 participants were included with analyses conducted on time points ≤ 26 weeks. The best performing model included: duration from baseline, average number of sets, and the main and interaction effects between outcome domain and intensity of load (% 1RM) expressed non-linearly. Model performance was not improved by the inclusion of participant training status or sex.

CONCLUSIONS

The current meta-analysis represents the most comprehensive investigation of dose-response relationships across a range of outcome domains commonly targeted within strength and conditioning to date. Results demonstrate the magnitude of improvements is predominantly influenced by training intensity of load and the outcome measured. When considering the effects of intensity as a % 1RM, profiles differ across outcome domains with maximum strength likely to be maximised with the heaviest loads, vertical jump performance likely to be maximised with relatively light loads (~ 30% 1RM), and power likely to be maximised with low to moderate loads (40-70% 1RM).

Effectiveness of short vs. long-distance sprint training on sprinting and agility performance in young soccer players

The purpose of this study was to examine the effects of short sprint-distance training (SST) compared with long sprint-distance training (LST), matched for the total session training volume, on short-, medium- and long-distance sprint performance and agility in young soccer players. Eighteen U19 male players (age: 17.1 ± 0.7 years; height: 178.0 ± 6.3 cm, body mass: 69.4 ± 6.6 kg) were randomly assigned to SST (n = 9) or LST (n = 9) group. The intervention programs were performed 2 times a week over 6 weeks. Before and after training period, 5 m, 10 m, 20 m, 30 m and 40 m sprint, and agility were assessed. Within-group analysis showed significant improvements (p ≤ 0.001) in 5 m, 10 m, 20 m, 30 m and 40 m sprint from pretest to posttest in SST (9.2%, 6.6%, 5.3%, 2.9%, and 2.5%, respectively) and LST (10.5%, 8.5%, 6.5%, 5.1%, and 4.7%, respectively). Players in both SST and LST also showed significant enhancements in agility from pretest to posttest. In the between-groups analysis, there were no differences between the sprint training groups (SST vs. LST) in any variable (p > 0.05). In conclusion, the findings of this study indicate that both sprint training distances used seem to be effective to improve soccer-specific performance measures. However, due to the better percentage changes obtained by LST group in all fitness variables, this method could be considered as preferred method.

The Relationship Between Isometric and Dynamic Strength Following Resistance Training: A Systematic Review, Meta-Analysis, and Level of Agreement

BACKGROUND

Maximal lower-body strength can be assessed both dynamically and isometrically; however, the relationship between the changes in these 2 forms of strength following resistance training is not well understood.

PURPOSE

To systematically review and analyze the effects of resistance training on changes in maximal dynamic (1-repetition-maximum back squat, deadlift, and power clean) and position-matched isometric strength (isometric midthigh pull and the isometric squat). In addition, individual-level data were used to quantify the agreement and relationship between changes in dynamic and isometric strength.

METHODS

Databases were systematically searched to identify eligible articles, and meta-analysis procedures were performed on the extracted data. The raw results from 4 studies were acquired, enabling bias and absolute reliability measures to be calculated using Bland-Altman test of agreement.

RESULTS

Eleven studies met the inclusion criteria, which resulted in 29 isometric-dynamic change comparisons. The overall pooled effect was 0.13 in favor of dynamic testing; however, the prediction interval ranged from g = -0.49 to 0.75. There was no evidence of bias (P = .825) between isometric and dynamic tests; however, the reliability coefficient was estimated to be 16%, and the coefficient of variation (%) was 109.27.

CONCLUSIONS

As a range of future effects can be expected when comparing isometric to dynamic strength changes following resistance training, and limited proportionality exists between changes in these 2 strength qualities, there is strong evidence that isometric and dynamic strength represent separate neuromuscular domains. These findings can be used to inform strength-assessment models in athlete populations.

The Effects of Strength and Conditioning Interventions on Sprinting Performance in Team Sport Athletes: A Systematic Review and Meta-Analysis

Murphy, A, Burgess, K, Hall, AJ, Aspe, RR, and Swinton, PA. The effects of strength and conditioning interventions on sprinting performance in team sport athletes: a systematic review and meta-analysis. J Strength Cond Res 37(8): 1692–1702, 2023—Linear sprinting is a key determinant of athletic performance within team sports. The aims of the review were to quantify and compare the effectiveness of popular strength and conditioning (S&C) training modes to improve sprint performance in team sport athletes, with additional focus on potential moderators and the relationships between improvements in physical factors (e.g., strength, power, and jump performance) and improvements in sprint performance. Inclusion was restricted to resistance, plyometric, sprint, and combined training interventions comprising team sport athletes. Multilevel, Bayesian’s meta-analysis and meta-regression models conducted with standardized mean difference effect sizes were used to investigate training modes and potential moderators. Weighted regression models conducted on shrunken estimates from initial Bayesian’s meta-analyses were used to quantify relationships between improvements in physical factors and sprint performance. Certainty of evidence was assessed using the grading of recommendations assessment development and evaluation (GRADE) approach. Similar improvements in sprint performance were obtained across training modes, with some evidence of the largest effects with resistance training ( = 0.55 [95% credible interval [CrI]: 0.36–0.78; very low certainty]). A strong moderating effect of training intensity was identified across all training modes with evidence of greater improvements in sprint performance with high-intensity training ( = 0.17 [95% CrI: 0.01–0.33; very low certainty]). Strong positive relationships were identified between improvements in all physical factors and sprint performance ( = 0.56 [95% CrI: 0.36–0.77; low certainty], = 0.80 [95% CrI: 0.50–1.0; low certainty], = 0.78 [95% CrI: 0.57–0.97; low certainty]). The findings indicate that focus on developing speed in team sport athletes should be placed on S&C training with high intensities, including the use of resisted sprint training.

When and How Do Soccer Players From a Semi-Professional Club Sprint in Match Play?

The aims of this study were to investigate the periods in which sprints occurred during official matches and analyze these sprints considering the effect of the playing position and different contextual variables. Electronic performance and tracking systems were used for the analysis of all sprints performed by players. Matches were recorded by video and synchronized with performance tracking data. A total of 252 sprints were analyzed. The greatest frequency of sprints was observed in the period 1 (0’–15’), followed by period 2 (15’–30’) and period 6 (75’–90’), regardless of the playing position (χ2 = 31.35; p = 0.051). Most sprints were non-linear (non-linear sprints: 97.6%; linear sprints: 2.4%) and without ball possession (without ball possession: 95.2%; with ball possession: 4.8%) for all playing positions, but the role of the sprint and the field area in which the sprint occurred were dependent on the position (p < 0.001). Specifically, players covered ~17.55 m per sprint, starting at ~10.34 km/h, reaching ~26.74 km/h, maximally accelerating at ~2.73 m/s2, and decelerating at ~3.61 m/s2. Overall, the playing position and contextual variables had no significant effect on physical performance variables analyzed during these sprints. Therefore, this study allows performance practitioners to have a better understanding of when and how soccer players sprint in match-play. In this regard, this study presents some training and testing strategies that may be considered to improve performance and decrease injury risk.

When and How do Professional Soccer Players Experience Maximal Intensity Sprints in Laliga?

This study aimed to 1) examine the periods in which maximal intensity sprints occurred during professional soccer matches and 2) analyze the maximal intensity sprints registered in match play considering the effect of playing position and other contextual variables. A total of 1252 match observations were collected from 277 male professional soccer players. Sprinting actions at maximal intensity were analyzed during 30 official matches, and both contextual and performance variables were collected using electronic performance and tracking systems. Maximal intensity sprints were more frequent in the first and last periods of the match (0'-15'; 75'-90'), regardless of the playing position (χ²=23.01; p=0.29; ES=0.07). These sprints were usually non-linear actions without possession of the ball and had different tactical purposes depending on the playing position. In addition, regarding the physical performance required by maximal intensity sprints, that the mean sprint duration ranged from ~4.9 s to ~9 s, the mean distance covered ranged from ~30 m to ~55 m, while the mean maximum velocity was between ~30.12 and ~32.80 km/h depending on the tactical purpose and playing position. In conclusion, professional soccer players need to be prepared during warm-ups for maximal intensity sprints in the first period of the match as well as maximal intensity sprints under high fatigue conditions given the frequency of sprints in the last period of the match. Also, training drills should be designed with a special focus on non-linear sprints without possession of the ball, based on the main tactical purpose of each position (e.g., CD: interceptions; MF: recovery runs; FB, WMF and FW: run the channel).