In multidirectional sports, speed matters.
But the ability to stop on a dime might matter even more.
Whether they're planting before a change of direction, defending in open space, or avoiding injury, athletes constantly need to decelerate rapidly.
Recent research from Li et al. (2025) provides a deeper understanding of the mechanical factors that distinguish elite decelerators from the rest.
Let’s break down the key determinants of better horizontal deceleration.
1. Horizontal Ground Reaction Force (GRF) Ratio
- The horizontal GRF ratio is how much force is directed backward (horizontally) compared to vertically.
- Athletes with a higher horizontal GRF ratio decelerate better because more of their effort is helping them slow down rather than just pushing into the ground.
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Coaching Cue: Teach athletes to position their center of mass (COM) low and behind the foot when braking.
2. Peak and Mean Horizontal GRF
- Simply put, more horizontal force means better deceleration.
- Peak and average braking forces during the first two steps after sprinting are strong indicators of stopping ability.
- These forces must be oriented properly, not just high in magnitude.
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Orientating Force: While vertical forces will still be highest, reaching ~4- 5x bodyweight, the horizontal forces will drive deceleration performance.
3. Approach Momentum (Mass × Velocity)
- Deceleration isn’t just about force; it’s about managing momentum.
- A 220lb athlete sprinting at 7.5 m/s has far more momentum than a 190lb athlete at the same speed, and stopping that momentum takes more force.
- Athletes with higher momentum have lower deceleration scores, even if they were strong.
- When evaluating deceleration, both approach velocity and mass must always be considered.
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Momentum Matters: More speed and mass make slowing down harder.
4. Technical Positioning
- Great decelerators aren't just strong, they're technically efficient:
- Lower center of mass
- Posterior COM relative to foot placement
- Efficient body lean
- These positions allow for a more effective application of horizontal braking force.
- This is a trainable skill through deceleration drills and coaching feedback.
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Counter Movement: If decelerating laterally, the foot will still be outside COM and pushing back from moving direction.
5. Eccentric Strength
- Effective deceleration requires "absorbing" (or attenuating) high forces in short windows.
- This requires strong eccentric capacity, especially in the quads, glutes, and hamstrings.
- Use exercises like eccentric split squats, deceleration drills, and yielding isometrics to build this quality.
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Build the Brakes: Train to develop the ability to pull the "E-Brake" for rapid deceleration and redirection.
6. Ground Contact Time (GCT)
- Shorter ground contact times are often associated with faster movement, but GCT reflects an athlete’s ability to tolerate force in deceleration.
- GCT isn't strongly tied to performance and is shorter in athletes with higher approach speeds.
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Force-Time: GCT should be viewed as a consequence, not a training target.
The Coaching Takeaway
Want to build better brakes? Focus on:
- Force orientation (horizontal > vertical)
- Positioning the COM behind the base of support
- Managing momentum, especially for larger athletes
- Eccentric strength and load tolerance
- Contextualizing deceleration within sprint momentum
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Integrate these mechanical principles into your assessments and training, and you'll help your athletes brake better, cut sharper, and stay healthier.
Reference
Li, W., Lin, J., Dos’Santos, T., & Turner, A. (2025). Mechanical determinants of superior horizontal deceleration performance in multidirectional sportspersons. Journal of Strength and Conditioning Research