Relationship Between Velocity Loss and Repetitions in Reserve in the Bench Press and Back Squat Exercises

This study aimed to compare the pattern of repetition velocity decline during a single set to failure performed against 4 relative loads in the bench press (BP) and full back squat (SQ) exercises. After an initial test to determine 1 repetition maximum (1RM) strength and load-velocity relationships, 20 men performed one set of repetitions to failure (MNR test) against loads of 50, 60, 70, and 80% 1RM in BP and SQ, on 8 random order sessions performed every 6–7 days. Velocity against the load that elicited a ∼1.00 m·s−1 (V1 m·s−1 load) was measured before and immediately after each MNR test, and it was considered a measure of acute muscle fatigue. The number of repetitions completed against each relative load showed high interindividual variability in both BP (coefficient of variation [CV]: 15–22%) and SQ (CV: 26–34%). Strong relationships were found between the relative loss of velocity in the set and the percentage of performed repetitions in both exercises (R2 = 0.97 and 0.93 for BP and SQ, respectively). Equations to predict repetitions left in reserve from velocity loss are provided. For a given magnitude of velocity loss within the set (15–65%), the percentages of performed repetitions were lower for the BP compared with the SQ for all loads analyzed. Acute fatigue after each set to failure was found dependent on the magnitude of velocity loss (r = 0.97 and 0.99 for BP and SQ, respectively) but independent of the number of repetitions completed by each pa...
Source: Journal of Strength and Conditioning Research - Category: Sports Medicine Tags: Original Research Source Type: research