Dataset Information

Metabolic Power Requirement of Change of Direction Speed in Young Soccer Players: Not All Is What It Seems.

ABSTRACT:

Purpose

The aims of this study were to 1) compare the metabolic power demand of straight-line and change of direction (COD) sprints including 45° or 90°-turns, and 2) examine the relation between estimated metabolic demands and muscular activity throughout the 3 phases of COD-sprints.

Methods

Twelve highly-trained soccer players performed one 25-m and three 20-m sprints, either in straight-line or with one 45°- or 90°-COD. Sprints were monitored with 2 synchronized 100-Hz laser guns to assess players' velocities before, during and after the COD. Acceleration and deceleration were derived from changes in speed over time. Metabolic power was estimated based on di Prampero's approach (2005). Electromyography amplitude (RMS) of 2 lower limb muscles was measured. The expected energy expenditure during time-adjusted straight-line sprints (matching COD sprints time) was also calculated.

Results

Locomotor-dependant metabolic demand was largely lower with COD (90°, 142.1±13.5 J.kg(-1)) compared with time-adjusted (effect size, ES = -3.0; 193.2±18.6 J.kg(-1)) and non-adjusted straight-line sprints (ES = -1.7; 168.4±15.3 J.kg(-1)). Metabolic power requirement was angle-dependent, moderately lower for 90°-COD vs. 45°-COD sprint (ES = -1.0; 149.5±10.4 J.kg(-1)). Conversely, the RMS was slightly- (45°, ES = +0.5; +2.1%, 90% confidence limits (±3.6) for vastus lateralis muscle (VL)) to-largely (90°, ES = +1.6; +6.1 (3.3%) for VL) greater for COD-sprints. Metabolic power/RMS ratio was 2 to 4 times lower during deceleration than acceleration phases.

Conclusion

Present results show that COD-sprints are largely less metabolically demanding than linear sprints. This may be related to the very low metabolic demand associated with the deceleration phase during COD-sprints that may not be compensated by the increased requirement of the reacceleration phase. These results also highlight the dissociation between metabolic and muscle activity demands during COD-sprints, which questions the use of metabolic power as a single measure of running load in soccer.

SUBMITTER: Hader K

PROVIDER: S-EPMC4773143 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Publications

Metabolic Power Requirement of Change of Direction Speed in Young Soccer Players: Not All Is What It Seems.

Hader Karim K Mendez-Villanueva Alberto A Palazzi Dino D Ahmaidi Saïd S Buchheit Martin M

PloS one 20160301 3

<h4>Purpose</h4>The aims of this study were to 1) compare the metabolic power demand of straight-line and change of direction (COD) sprints including 45° or 90°-turns, and 2) examine the relation between estimated metabolic demands and muscular activity throughout the 3 phases of COD-sprints.<h4>Methods</h4>Twelve highly-trained soccer players performed one 25-m and three 20-m sprints, either in straight-line or with one 45°- or 90°-COD. Sprints were monitored with 2 synchronized 100-Hz laser gu ...[more]

PMID: 26930649

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Project description:Cutting manoeuvres are important actions associated with soccer performance and a key action associated with non-contact anterior cruciate ligament injury; thus, training interventions that can improve cutting performance and movement quality are of great interest. The aim of this study, therefore, was to determine the effects of a six-week change of dire[ction (COD) speed and technique modification training intervention on cutting performance and movement quality in male youth soccer players (U17s, n = 8) in comparison to a control group (CG) (U18s, n = 11) who continued 'normal' training. Cutting performance was assessed based on completion time and COD deficit, and the field-based cutting movement assessment score (CMAS) qualitative screening tool was used to assess cutting movement quality. Significant main effects for time (pre-to-post changes) (p ? 0.041, ?2 = 0.224-0.839) and significant interaction effects of time and group were observed for cutting completion times, COD deficits, and CMASs. Improvements in completion time (p < 0.001, g = 1.63-1.90, -9% to -11% vs. -5% to 6%) and COD deficit (p ? 0.012, g = -1.63 to -2.43, -40-52% vs. -22% to -28%) for the COD intervention group (IG) were approximately two-times greater than the CG. Furthermore, lower CMASs (i.e., improved cutting movement quality) were only observed in the IG (p ? 0.025, g = -0.85 to -1.46, -23% to -34% vs. 6-19%) compared to the CG. The positive changes in CMASs were attributed to improved cutting technique and reduced incidences of high-risk deficits such as lateral trunk flexion, extended knee postures, knee valgus, hip internal rotation, and improved braking strategies. The results of this study indicate that COD speed and technique modification training, in addition to normal skills and strength training, improves cutting performance and movement quality in male youth soccer players. Practitioners working with male youth soccer players should implement COD speed and technique modification training to improve cutting performance and movement quality, which may decrease potential injury-risk.

Project description:The aim of the study was to assess the effects of multi-directional plyometric training (MPT) on vertical jump height, change of direction speed (CODS), and dynamic postural control (DPC) of soccer players under 21 year (U-21). Twenty-seven male soccer players were randomly allocated to either an experimental group (EG; n = 14; age: 19.0 ± 0.9 years) or a control group (CG; n = 13; age: 19.0 ± 0.7 years). The EG introduced 6 weeks MPT, 2 days per week into their in-season training, while CG continued training without change. Measurements of vertical jump height, CODS and DPC were completed at the beginning and end of the 6 week MPT. ANOVA demonstrated a significant group × time interaction for SJ (F = 6.03, p = 0.021), CMJ (F = 9.10, p = 0.006), and T-Test (F = 10.46, p = 0.002). The Bonferroni Post Hoc test demonstrated significant increase for the three tests in both group (EG and CG). For SJ (EG: p < 0.001; CG: p < 0.001), CMJ (EG: p < 0.001; CG: p = 0.005) and T-Test (EG: p < 0.001; CG: p = 0.02). For DPC on the dominant leg, there was a significant group × time interaction for four axes [anterior (F = 5.48, p = 0.028), antero-lateral (F = 4.82, p = 0.038), postero-lateral (F = 4.82, p = 0.038), and medial (F = 6.77, p = 0.015)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in four axes (anterior, antero-lateral, postero-lateral and medial). Furthermore DPC on the non-dominant leg, there was a significant group × time interaction for three axes [lateral (F = 8.09, p = 0.009), postero-lateral (F = 11.92, p = 0.002), and medial (F = 5.84, p = 0.023)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in three axes (lateral, postero-lateral, and medial). In conclusion, incorporating MPT into the in-season regimen of under 21 soccer players improved performance of various indices related to soccer activity (i.e., CMJ, CODS, and DPC). MPT has the potential to be appealing to coaches, as it requires little time while yielding valuable results in the physical preparation of soccer players.

Dataset Information

Metabolic Power Requirement of Change of Direction Speed in Young Soccer Players: Not All Is What It Seems.

Purpose

Methods

Results

Conclusion

Publications

Metabolic Power Requirement of Change of Direction Speed in Young Soccer Players: Not All Is What It Seems.

Similar Datasets

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