Relationship Between Fatigue Index and Number of Repetition Maxima with Sub-Maximal Loads in Biceps Curl

Abstract

The aim of this study was to investigate the relationship between the number of repetition maxima to volitional failure (RM) at 60%, 75%, 90% of 1RM and fatigue index (FI), a determinant of the muscular endurance level. Thirty four resistance trained male participants attended two testing sessions. The first session was conducted to assess 1RM load and RM at 60%, 75% and 90% of 1RM in the supine biceps curl (SBC) exercise. In the second session, a FI test protocol consisting of five sets of SBC with 90 s rest between sets was performed to determine FI values. Each set was performed to volitional failure using a sub-maximal load in the range of 15-20RM. Hypothetical high FI and low FI groups (17 participants with the highest and lowest FI values, respectively) were formed for statistical analyses. ANOVA results revealed that RM at 60%, 75%, 90% of 1RM were not significantly different between FI groups when controlled for mean repetition tempo (p=0.11, p=0.38, p=0.13, respectively). Pearson’s correlation coefficients revealed that no significant relationship was present between FI values and RM at 60%, 75%, 90% of 1RM (p=0.40, p=0.46, p=0.14, respectively). In conclusion, the muscular endurance level of participants defined in terms of FI value was not an indicator of RM in SBC. Therefore, athletes with different muscular endurance levels can use similar percentages of 1RM in biceps curl exercise in their training programs when the aim is to elicit training adaptations related to specific RM zones.

Is Ischemic Preconditioning Intervention Occlusion-Dependent to Enhance Resistance Exercise Performance?

“…Although we found time 3 treatment interaction on total workload (Figure 2), which is a variable directly related with number of repetitions, no treatment effect or interaction was observed for FI (Figure 3B). In this sense, our findings are supported by another study (35) that reported no relationship between FI and maximal number of repetitions at several percentages of 1RM. The number of repetitions is dependent on the muscle fiber-type recruitment that influences the ability of a muscle group to continue contracting against a submaximal load for a specific number of repetitions (6,30).…”

Fatigue and Metabolic Responses during Repeated Sets of Bench Press Exercise to Exhaustion at Different Ranges of Motion

“…However, performing repetitions to volitional fatigue during resistance exercise may be desirable if the aim is to induce hypertrophy or increase muscle strength ( Lasevicius et al, 2022 ; Singal et al, 2018 ), through high metabolic ( Goto et al, 2005 ) or muscular loads ( Schoenfeld, 2010 ) and neural adaptations ( Gabriel et al, 2001 ; Walker et al, 2012 ). Fatigue may be quantified by measuring the total number of repetitions ( Pekünlü and Atalaǧ, 2013 ), the total work done ( Pareja-Blanco et al, 2017 ), the percentage drop in performance ( Tsoukos et al, 2021 ; Tsoukos and Bogdanis, 2023b ) or the slope of performance decrement ( Tsoukos and Bogdanis, 2023a ).…”

Muscle Mass and Training Status Do Not Affect the Maximum Number of Repetitions in Different Upper-Body Resistance Exercises

“…Although the relationship between the percent of 1RM and the RM's performed is affected by the movement velocity, the previous above-mentioned studies did not control this variable [4,5,8,9]. Consequently, studies on the relationship RM`s and %1RM that controlled the movement velocity are scarce [13]. In addition, controversial results have been shown in studies comparing this relationship in trained and untrained participants [8,9].…”