Effect of Extreme Volume-Load Differences for a Single Unilateral Exercise During In-Season Resistance Training on Measures of Bilateral Strength, Power, and Speed in Collegiate American Football Players.

Crawley, K, Adams, KJ, DeBeliso, M, and Lawrence, MM. Effect of Extreme Volume-Load Differences for a Single Unilateral Exercise During In-Season Resistance Training on Measures of Bilateral Strength, Power, and Speed in Collegiate American Football Players. J Strength Cond Res XX(X): 000-000, 2023-This study examined the impact extreme volume-load differences for a single weekly exercise, when all other exercises' volume loads were similar, would have on American football performance variables after in-season resistance training (RT). Twenty male National Collegiate Athletic Association (NCAA) American footballers (18-23 years, 98.4 ± 19.3 kg) were randomly assigned to an extreme high-volume low-intensity (EHVLI; n = 11) group or a low-volume high-intensity (LVHI; n = 9) group. Subjects performed the same evidence-based RT exercises and volume loads for 8 weeks thrice weekly, with the only differences being once weekly unilateral reverse dumbbell lunge (EHVLI) or unilateral Hatfield safety bar back squat (LVHI) exercises performed with different volume loads. Performance variables were assessed 1 week before (PRE) and after (POST) 8 weeks of RT. A 2-way analysis of variance with repeated measures and the Sidak post hoc test were used (p < 0.05). Extreme high-volume low-intensity had no significant (p > 0.05) PRE-to-POST RT changes in muscular strength in 1 repetition maximum (251.8 ± 48.7 to 274.6 ± 61.3 kg) or power in vertical jump (79.2 ± 8.8 to 78.2 ± 10.8 cm). Conversely, LVHI had significant (p < 0.05) PRE-to-POST RT improvements in strength (249.2 ± 54.4 to 284.1 ± 55.0 kg) and power (72.8 ± 11.4 to 76.3 ± 10.0 cm). Furthermore, LVHI vs. EHVLI displayed significantly greater percentage difference increases from PRE values in muscular power (6.7% ± 7.2 vs. -1.3% ± 6.0, respectively), with no significant differences between groups (LVHI vs. EHVLI) in muscular strength (8.8% ± 3.1 vs. 6.7% ± 8.0, respectively) and 10-yard acceleration (2.2% ± 5.6 vs. 3.2% ± 5.6, respectively). For in-season RT of strength and power in collegiate American football players, all exercises performed should use evidence-based volume loads to optimize adaptations because a single exercise performed with extreme volume load may limit muscular strength and power development.