Unilateral vs. Bilateral Squat Training for Strength, Sprints, and Agility in Academy Rugby Players

Abstract

The purpose of this study was to investigate the effects of a 5-week lower-limb unilateral or bilateral strength program on measures of strength, sprinting, and change of direction speed. Eighteen academy rugby players (18.1 ± 0.5 years, 97.4 ± 11.3 kg, 183.7 ± 11.3 cm) were randomly assigned to either a unilateral (UNI) or bilateral (BI) group. The UNI group squatted exclusively with the rear elevated split squat (RESS), whereas the BI group trained only with the bilateral back squat (BS). Both groups trained at a relative percentage of the respective 1 repetition maximum (1RM) twice weekly over a 5-week period. Subjects were assessed at baseline and postintervention for 1RM BS, 1RM RESS, 10-m sprint, 40-m sprint, and pro-agility. There was a significant main effect of time for 1RM BS (F1,16 = 86.5, p < 0.001), ES (0.84 < Cohen d < 0.92), 1RM RESS (F1,16 = 133.0, p < 0.001), ES (0.89 < Cohen d < 0.94), 40-m sprint (F1,16 = 14.4, p = 0.002), ES (0.47 < Cohen d < 0.67) and pro-agility (F1,16 = 55.9, p < 0.001), ES (0.77 < Cohen d < 0.89), but not 10-m sprints (F1,16 = 2.69, p = 0.121), ES (0.14 < Cohen d < 0.38). No significant interactions between group and time were observed for any of the dependent variables. This is the first study to suggest that BI and UNI training interventions may be equally efficacious in improving measures of lower-body strength, 40-m speed, and change of direction in academy level rugby players.

Effects of 6-week squat, deadlift, or hip thrust training program on speed, power, agility, and strength in experienced lifters: A pilot study

“…This pilot study successfully demonstrated that an investigation between the squat, deadlift, and hip thrust is feasible; in addition, this present study provides effect-sizes from which 16,18 , such a conclusion cannot be directly drawn from pilot data.…”

A Pilot Analysis: Can the Bulgarian Split-Squat Potentiate Sprint Acceleration in Strength-Trained Men?

“…To run faster, the individual must be able to transfer their general strength to the sprint step by ensuring that the nervous system can control the augmented force output (Tsimahidis et al, 2010). This could result in greater force and power generation within the sprint step, and indeed strength and power training can improve speed (Lockie, Murphy, Schultz, Knight, & Janse de Jonge, 2012;Speirs, Bennett, Finn, & Turner, 2016). To increase the specificity of resistance training for speed development, it is important to incorporate unilateral exercises (Lockie et al, 2012;Speirs et al, 2016).…”

“…This could result in greater force and power generation within the sprint step, and indeed strength and power training can improve speed (Lockie, Murphy, Schultz, Knight, & Janse de Jonge, 2012;Speirs, Bennett, Finn, & Turner, 2016). To increase the specificity of resistance training for speed development, it is important to incorporate unilateral exercises (Lockie et al, 2012;Speirs et al, 2016). One example of a unilateral strength exercise is the Bulgarian split-squat (BSS), which involves an individual performing a single-leg squat while the non-working leg is supported on a bench (McCurdy, Langford, Cline, Doscher, & Hoff, 2004).…”

“…One example of a unilateral strength exercise is the Bulgarian split-squat (BSS), which involves an individual performing a single-leg squat while the non-working leg is supported on a bench (McCurdy, Langford, Cline, Doscher, & Hoff, 2004). Due to the specificity of the movement when compared to the sprint step (Speirs et al, 2016), the BSS could be used to potentiate sprint performance. However, there is currently no research that has investigated whether a unilateral strength exercise such as the BSS can potentiate sprint acceleration in trained individuals.…”

Hip Musculoskeletal Conditions and Associated Factors That Influence Squat Performance: A Systematic Review

“…Research has shown that both unilateral and bilateral squat training can improve lower body strength, sprint speed, and agility in individuals. 1 Both unilateral and bilateral squats are also used as assessments of dynamic lower-extremity motor control. [2][3][4][5][6][7] The utility of unilateral and bilateral squats for training and assessment has made these movements a foundational part of athletic and exercise training programs.…”