BOOK OF ABSTRACTS OF THE 27TH ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCE (30 August – 2 September 2022) Effect of bench press execution velocity, load, and load distribution on perceived exertion and number of repetitions performed. Micheli L, Shoaei V, Francia P, Grossi T, Benelli P, Federici A, Lucertini F, Zoffoli L, Ferri Marini C.

INTRODUCTION: Barbell bench press exercise adaptations depend on how several of its parameters are tailored. Exercise intensity, which plays a pivotal role in resistance exercise adaptation, is generally prescribed as the load to be lifted for a specific number of repetitions. Traditionally, load is expressed as a percentage of one repetition maximum (i.e., the greatest resistance that can be lifted in a controlled manner with good posture) (1). However, execution velocity also affects exercise intensity (2). Moreover, no studies assessed the effect of load distribution (i.e., the distance between the disc stacks at the two sides of the barbell) on exercise intensity. The present study aimed to evaluate how different combinations of load, execution velocity, and load distribution on the barbell affect the number of repetitions to failure (REPfailure), and rating of perceived exertion (RPEfatigue) and number of repetitions (REPfatigue) at fatigue onset. METHODS: Eleven males (age 23.3±1.8 years) performed bench press exercises to failure following the National Strength and Conditioning Association guidelines (3). Three loads (80% [1-RM80], 65% [1-RM65], and 50% [1-RM50] of one repetition maximum), execution velocities (90% [V90], 70% [V70], and 50% [V50] of maximal concentric velocity), and two distributions (narrow and wide) were randomly combined. Participants’ perceived exertion was also recorded during the repetitions eccentric phases (4). Three separate three-way repeated-measure ANOVAs (α=0.05) were performed to assess the effect of load, velocity, and distribution on REPfailure, RPEfatigue, and REPfatigue normalized as a percentage of REPfailure. RESULTS: REPfailure was affected by load (p<0.001), velocity (p<0.001), and distribution (p=0.005). The interactions between load and velocity (p<0.001) and load and distribution (p=0.004) showed a significant effect on REPfailure, whereas the interaction between velocity and distribution was not significant (p=0.360). More REPfailure were performed using lower loads (1-RM50=21.2±3.5; 1-RM65=12.1±1.8; 1- RM80=4.8±1.3), higher velocities (V90=14.2±8.0; V70=12.7±7.2; V50=11.0±5.9), and wider distribution (wide=13.2±7.5; narrow=12.2±6.8). RPEfatigue and REPfatigue were affected by load (p<0.001 and p=0.007, respectively) and velocity (p<0.001 and p<0.001, respectively), whereas they were not affected by distribution (p=0.510 and p=0.571, respectively) or the two-way interaction effects. Using higher loads yielded higher RPEfatigue but lower REPfatigue, while RPEfatigue and REPfatigue were higher when slower velocities were used. CONCLUSION: The present study shows that, when prescribing resistance exercise intensity, not only exercise load but also execution velocity and load distribution should be considered. 1. American College of Sports Medicine, Med Sci Sports Exerc, 2009; 2. Sakamoto A, et al., J Strength Cond Res, 2006; 3. Earle RW, et al., NSCA’s essentials of personal training, 2004; 4. Gearhart, RE, et al., J Strength Cond Res, 2001.