Biomechanical, Anthropometric and Psychological Determinants of Barbell Bench Press Strength.

The purpose of this study was to improve our understanding of the relative contributions of biomechanical, anthropometric, and psychological factors in explaining maximal bench press (BP) strength in a heterogeneous, resistance-trained sample. Eighteen college-aged participants reported to the laboratory for three visits. The first visit consisted of psychometric testing. The second visit assessed participants' anthropometrics, additional psychometric outcomes, and bench press one repetition maximum (1RM). Participants performed isometric dynamometry testing for horizontal shoulder adduction and elbow extension at a predicted sticking point joint position. Multiple linear regression was used to examine the relationships between the biomechanical, anthropometric, and psychological variables and BP 1RM. Our primary multiple linear regression accounted for 43% of the variance in BP strength (F(3,14) = 5.34, p = 0.01; R2 = 0.53; adjusted R2 = 0.43). The sum of peak isometric net joint moments from the shoulder and elbow had the greatest standardized effect (0.59), followed by lean body mass (0.27) and self-efficacy (0.17). The variance in BP 1RM can be similarly captured (R2 = 0.48) by a single principal component containing anthropometric, biomechanics, and psychological variables. Pearson correlations with BP strength were generally greater among anthropometric and biomechanical variables as compared to psychological variables. These data suggest that BP strength among a heterogeneous, resistance-trained population is explained by multiple factors and is more strongly associated with physical than psychological variables.

The Minimum Effective Training Dose Required for 1RM Strength in Powerlifters.

The aim of this multi-experiment paper was to explore the concept of the minimum effective training dose (METD) required to increase 1-repetition-maximum (1RM) strength in powerlifting (PL) athletes. The METD refers to the least amount of training required to elicit meaningful increases in 1RM strength. A series of five studies utilising mixed methods, were conducted using PL athletes & coaches of all levels in an attempt to better understand the METD for 1RM strength. The studies of this multi-experiment paper are: an interview study with elite PL athletes and highly experienced PL coaches (n = 28), an interview and survey study with PL coaches and PL athletes of all levels (n = 137), two training intervention studies with intermediate-advanced PL athletes (n = 25) and a survey study with competitive PL athletes of different levels (n = 57). PL athletes looking to train with a METD approach can do so by performing ~3-6 working sets of 1-5 repetitions each week, with these sets spread across 1-3 sessions per week per powerlift, using loads above 80% 1RM at a Rate of Perceived Exertion (RPE) of 7.5-9.5 for 6-12 weeks and expect to gain strength. PL athletes who wish to further minimize their time spent training can perform autoregulated single repetition sets at an RPE of 9-9.5 though they should expect that strength gains will be less likely to be meaningful. However, the addition of 2-3 back-off sets at ~80% of the single repetitions load, may produce greater gains over 6 weeks while following a 2-3-1 squat-bench press-deadlift weekly training frequency. When utilizing accessory exercises in the context of METD, PL athletes typically utilize 1-3 accessory exercises per powerlift, at an RPE in the range of 7-9 and utilize a repetition range of ~6-10 repetitions.

Sex Differences in Resistance Training: A Systematic Review and Meta-Analysis.

Roberts, BM, Nuckols, G, and Krieger, JW. Sex differences in resistance training: A systematic review and meta-analysis. J Strength Cond Res 34(5): 1448-1460, 2020-The purpose of this study was to determine whether there are different responses to resistance training for strength or hypertrophy in young to middle-aged males and females using the same resistance training protocol. The protocol was pre-registered with PROSPERO (CRD42018094276). Meta-analyses were performed using robust variance random effects modeling for multilevel data structures, with adjustments for small samples using package robumeta in R. Statistical significance was set at P < 0.05. The analysis of hypertrophy comprised 12 outcomes from 10 studies with no significant difference between males and females (effect size [ES] = 0.07 ± 0.06; P = 0.31; I = 0). The analysis of upper-body strength comprised 19 outcomes from 17 studies with a significant effect favoring females (ES = -0.60 ± 0.16; P = 0.002; I = 72.1). The analysis of lower-body strength comprised 23 outcomes from 23 studies with no significant difference between sexes (ES = -0.21 ± 0.16; P = 0.20; I = 74.7). We found that males and females adapted to resistance training with similar effect sizes for hypertrophy and lower-body strength, but females had a larger effect for relative upper-body strength. Given the moderate effect size favoring females in the upper-body strength analysis, it is possible that untrained females display a higher capacity to increase upper-body strength than males. Further research is required to clarify why this difference occurs only in the upper body and whether the differences are due to neural, muscular, motor learning, or are an artifact of the short duration of studies included.

Biomechanical, Anthropometric, and Psychological Determinants of Barbell Back Squat Strength.

Vigotsky, AD, Bryanton, MA, Nuckols, G, Beardsley, C, Contreras, B, Evans, J, and Schoenfeld, BJ. Biomechanical, anthropometric, and psychological determinants of barbell back squat strength. J Strength Cond Res 33(7S): S26-S35, 2019-Previous investigations of strength have only focused on biomechanical or psychological determinants, while ignoring the potential interplay and relative contributions of these variables. The purpose of this study was to investigate the relative contributions of biomechanical, anthropometric, and psychological variables to the prediction of maximum parallel barbell back squat strength. Twenty-one college-aged participants (male = 14; female = 7; age = 23 ± 3 years) reported to the laboratory for 2 visits. The first visit consisted of anthropometric, psychometric, and parallel barbell back squat 1 repetition maximum (1RM) testing. On the second visit, participants performed isometric dynamometry testing for the knee, hip, and spinal extensors in a sticking point position-specific manner. Multiple linear regression and correlations were used to investigate the combined and individual relationships between biomechanical, anthropometric, and psychological variables and squat 1RM. Multiple regression revealed only 1 statistically predictive determinant: fat-free mass normalized to height (standardized estimate ± SE = 0.6 ± 0.3; t(16) = 2.28; p = 0.037). Correlation coefficients for individual variables and squat 1RM ranged from r = -0.79 to 0.83, with biomechanical, anthropometric, experiential, and sex predictors showing the strongest relationships, and psychological variables displaying the weakest relationships. These data suggest that back squat strength in a heterogeneous population is multifactorial and more related to physical rather than psychological variables.