Unilateral vs. Bilateral Squat Training for Strength, Sprints, and Agility in Academy Rugby Players.
Level 2 - randomized trial
Randomized parallel-group trial
PubMed 26200193 · doi:10.1519/JSC.0000000000001096
What was done
Eighteen academy rugby players (mean age 18.1 ± 0.5 years, body mass 97.4 ± 11.3 kg) were randomly assigned to either a unilateral training group (rear elevated split squat; UNI) or a bilateral training group (back squat; BI). Both groups trained twice weekly for 5 weeks at relative percentages of their respective 1-repetition maximum (1RM). Pre- and post-intervention assessments measured 1RM back squat, 1RM rear elevated split squat, 10-m sprint, 40-m sprint, and pro-agility.
What was found
Both groups showed significant main effects of time for 1RM back squat (F1,16 = 86.5, p < 0.001, Cohen d 0.84 to 0.92), 1RM rear elevated split squat (F1,16 = 133.0, p < 0.001, Cohen d 0.89 to 0.94), 40-m sprint (F1,16 = 14.4, p = 0.002, Cohen d 0.47 to 0.67), and pro-agility (F1,16 = 55.9, p < 0.001, Cohen d 0.77 to 0.89), but not 10-m sprint (F1,16 = 2.69, p = 0.121, Cohen d 0.14 to 0.38). No significant group-by-time interactions were found for any outcome, indicating comparable improvements between modalities.
Why it matters
Rear-elevated split squats can serve as an effective alternative to bilateral back squats for improving lower-body strength, top-end sprint speed, and change-of-direction ability in trained athletes.
Limits
The sample size was small (n = 18 total) and the intervention was short (5 weeks). The sample was restricted to young male academy rugby players, limiting generalizability to female athletes or untrained populations. There was no non-training control group.