Which Strength Qualities Matter Most for Sprinting? Partitioning Unique and Shared Variance in a Multivariable Model

Area of Science:

• Sports Science
• Biomechanics
• Human Movement

Background:

• Previous research linked individual strength qualities to sprint performance.
• The unique and shared contributions of various strength qualities to sprint performance remain underexplored.
• A comprehensive analysis of all strength qualities concurrently was lacking.

Purpose of the Study:

• To concurrently model five distinct strength qualities against sprint performance.
• To quantify the unique and shared variance each strength quality contributes to sprint performance across different distances.
• To identify the most influential strength qualities for optimizing sprint speed.

Main Methods:

• Eighty-four resistance-trained individuals (62 male, 22 female) participated.
• Strength qualities assessed included: heavy dynamic, fast dynamic, reactive, isometric, and explosive.
• Multiple regression analysis was used to model strength qualities against 5-40m sprint performance and maximal velocity.

Main Results:

• A combination of countermovement jump height (explosive), 3RM back squat (heavy dynamic), and drop jump reactive strength index (reactive) explained 75.2% of sprint performance variance.
• Heavy dynamic and reactive strength qualities were significant predictors of sprint performance.
• Adding isometric strength measures (peak force or force at 100ms) provided negligible additional explanatory power.

Conclusions:

• Explosive, heavy dynamic, and reactive strength qualities are crucial for sprint performance.
• These three strength qualities collectively account for the majority of variance in sprint performance.
• Focusing training on improving explosive, heavy dynamic, and reactive strength may be most effective for enhancing sprint speed.