The deceleration paradox: the faster you run the slower you stop

This study examined the effect of approach momentum on horizontal deceleration (DEC) performance. Eighty team sports athletes performed three maximal horizontal DEC trials from a 15 m approach. Sprint performance was recorded using timing gates and instantaneous velocity was collected using a radar device. Correlation and multiple regression analysis were conducted to analyze the relationships between DEC-related variables. Between-subject (top 50% vs. bottom 50%) differences in DEC-related variables were also determined. Greater mean DEC was significantly correlated with lower approach momentum (r = -0.354, p = 0.001). Compared to lower DEC performers (in terms of mean and peak values), greater performers showed statistically significantly lower peak approach velocity (ES = 0.41-0.66, p < 0.05) and lower peak approach momentum (ES = 0.48-0.60, p < 0.05). Furthermore, the standardized Beta values of the multiple regression analysis demonstrated that body mass is a greater determinant of DEC performance compared to approach velocity. In conclusion, practitioners should be aware that approach momentum (body mass and approach velocity) is a factor influencing DEC performance, and an inverse relationship exists. Thus, to evaluate maximal DEC ability, approach velocity and body mass must be considered.