# Pairwise Comparison of Effects of Linear vs. Change of Direction Short Bout Sprint Intervals on Physical Performance of Youth Male Soccer Players

## TL;DR

This study compares the effects of sprint interval training with and without change of direction on physical performance in young male soccer players over 12 weeks.

## Contribution

The study provides empirical evidence that change of direction sprint intervals improve physical performance more effectively than linear sprint intervals in youth soccer players.

## Key findings

- The RS–CoD group showed greater improvements in agility (93639 test) compared to RS–LiN and SOC groups.
- RS–CoD led to larger gains in explosive power (SJ and CMJ) and sprint performance (5 m and 20 m) than other groups.
- Change of direction sprint intervals were found to be more effective training stimuli for youth soccer players.

## Abstract

Our study aimed to examine and compare the effects of 12-week repeated sprint intervals with change of direction and linear sprint intervals on physical performance in young soccer players. In this randomized, parallel three-group study, we included 60 male soccer players assigned to (i) a sprint interval with change of direction group (RS–CoD; n = 20); (ii) a linear sprint interval group (RS–LiN; n = 20); and (iii) a soccer group (SOC; n = 20). Physical performance included explosive power (countermovement jump [CMJ] and squat jump [SJ]), agility (T505, 93,639, 20Y), speed (sprints over 5 m, 10 m and 20 m), anaerobic capacity (the Running-Based Anaerobic Sprint Test [RAST]) and maximal oxygen uptake (VO2max). Over the 12 weeks, the RS–CoD group displayed significantly beneficial effects in the 93639 test (effect size [ES] = 0.42), compared to the RS–LiN (ES = 0.18) and SOC (ES = 0.12) groups. The RS–CoD group also had larger improvements in their SJ (ES = 0.87; RS–LiN 0.37; SOC 0.18), CMJ (ES = 0.56; RS–LiN 0.39; SOC 0.43), 20Y test (ES = 1.05; RS–LiN 0.67; SOC 0.56) and sprints at 5 m (ES = 1.18; RS–LiN 0.50; SOC 0.21) and 20 m (ES = 1.43; RS–LiN 0.71; SOC 0.25). The RS–CoD group displayed more beneficial improvements, making the CoD interval sprints effective training stimuli.