Very-Heavy Sled Training for Improving Horizontal-Force Output in Soccer Players.
BACKGROUND
Sprint running acceleration is a key feature of physical performance in team sports, and recent literature shows that the ability to generate large magnitudes of horizontal ground-reaction force and mechanical effectiveness of force application are paramount. The authors tested the hypothesis that very-heavy loaded sled sprint training would induce an improvement in horizontal-force production, via an increased effectiveness of application.


METHODS
Training-induced changes in sprint performance and mechanical outputs were computed using a field method based on velocity-time data, before and after an 8-wk protocol (16 sessions of 10- × 20-m sprints). Sixteen male amateur soccer players were assigned to either a very-heavy sled (80% body mass sled load) or a control group (unresisted sprints).


RESULTS
The main outcome of this pilot study is that very-heavy sled-resisted sprint training, using much greater loads than traditionally recommended, clearly increased maximal horizontal-force production compared with standard unloaded sprint training (effect size of 0.80 vs 0.20 for controls, unclear between-groups difference) and mechanical effectiveness (ie, more horizontally applied force; effect size of 0.95 vs -0.11, moderate between-groups difference). In addition, 5-m and 20-m sprint performance improvements were moderate and small for the very-heavy sled group and small and trivial for the control group, respectively. Practical Applications: This brief report highlights the usefulness of very-heavy sled (80% body mass) training, which may suggest value for practical improvement of mechanical effectiveness and maximal horizontal-force capabilities in soccer players and other team-sport athletes.


RESULTS
This study may encourage further research to confirm the usefulness of very-heavy sled in this context.
Jean-Benoît
JB
Morin
George
G
Petrakos
Pedro
P
Jiménez-Reyes
Scott R
SR
Brown
Pierre
P
Samozino
Matt R
MR
Cross
D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D006801:Humans; D008297:Male; D064797:Physical Conditioning, Human / Q000379:methods*; D010865:Pilot Projects; D012420:Running; D012916:Soccer; D055815:Young Adult
acceleration; football; performance; power; resistance training