One repetition maximum bench press performance: A new approach for its evaluation in inexperienced males and females: A pilot study

Predicting repeat power ability through common field assessments: is repeat power ability a unique physical quality?

Background

The repeat power ability (RPA) assessment is used to test the ability to repeatedly produce maximal ballistic efforts with an external load. The underpinning physical qualities influencing RPA are undetermined. This study aimed to gain further insight into the physical qualities that determine RPA by analysing the association between physical qualities and an assessment of RPA.

Materials and methods

Ten well-trained male field hockey players performed an RPA assessment consisting of 20 repetitions of loaded countermovement jumps (LCMJ20), with a percent decrement score of peak power output calculated. Over a two-week period, each participant performed the YoYo Intermittent Recovery Test 2 (IRT2), a repeated speed ability assessment incorporating a 180° change of direction (RSA180), a 40-meter linear speed test (40 mST), an isometric mid-thigh pull (IMTP), a countermovement jump (CMJ), and a 3-repetition maximum half squat (HS) assessment. Pearson's correlation analysis was used to determine the strength of relationships between each assessment variable and the LCMJ20. The assessment variables with the strongest relationships within each assessment were used in a stepwise multiple linear regression analysis to determine the best predictor model of LCMJ20.

Results

RSA180percent decrement score (RSA180% had a very strong, significant relationship with LCMJ20 (r = 0.736: p < 0.05). HS relative strength (HSrel) was found to have a significant and very strong, negative relationship with LCMJ20 (r =  - 0.728: p < 0.05). Stepwise multiple linear regression analysis showed RSA180 to explain 48.4% of LCMJ20 variance (Adjusted R2 = 0.484) as the only covariate included in the model.

Conclusion

The findings indicate that RSA180 as a repeated high intensity effort (RHIE) task is strongly related to LCMJ20 and is also the best predictor of LCMJ20. This may suggest that RPA can provide practitioners with information on RHIE performance. The variance between assessment methods indicates that RPA may be a distinct physical quality, future research should assess other physical capacities to better understand the factors contributing to RPA.

Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations

ABSTRACT

Nuzzo, JL. Narrative review of sex differences in muscle strength, endurance, activation, size, fiber type, and strength training participation rates, preferences, motivations, injuries, and neuromuscular adaptations. J Strength Cond Res 37(2): 494-536, 2023-Biological sex and its relation with exercise participation and sports performance continue to be discussed. Here, the purpose was to inform such discussions by summarizing the literature on sex differences in numerous strength training-related variables and outcomes-muscle strength and endurance, muscle mass and size, muscle fiber type, muscle twitch forces, and voluntary activation; strength training participation rates, motivations, preferences, and practices; and injuries and changes in muscle size and strength with strength training. Male subjects become notably stronger than female subjects around age 15 years. In adults, sex differences in strength are more pronounced in upper-body than lower-body muscles and in concentric than eccentric contractions. Greater male than female strength is not because of higher voluntary activation but to greater muscle mass and type II fiber areas. Men participate in strength training more frequently than women. Men are motivated more by challenge, competition, social recognition, and a desire to increase muscle size and strength. Men also have greater preference for competitive, high-intensity, and upper-body exercise. Women are motivated more by improved attractiveness, muscle "toning," and body mass management. Women have greater preference for supervised and lower-body exercise. Intrasexual competition, mate selection, and the drive for muscularity are likely fundamental causes of exercise behaviors in men and women. Men and women increase muscle size and strength after weeks of strength training, but women experience greater relative strength improvements depending on age and muscle group. Men exhibit higher strength training injury rates. No sex difference exists in strength loss and muscle soreness after muscle-damaging exercise.

A Novel Assessment Technique Does Not Produce More Reliable Estimates of Maximal Neuromuscular Strength

Accurate determinations of individuals' one-repetition maximum (1RM) are critical when evaluating the effectiveness of an exercise intervention involving progressive resistance training (RT). Traditional ("bottom-up"; BT) testing methods involve progressions from low to maximal loads and are commonly used in clinical and laboratory environments. Concerns about the reliability of BT testing in certain populations suggest a different technique may be more effective. Purpose: To compare the reliability and effectiveness of traditional 1RM testing to a novel technique (TDT) involving progressive load reductions and a starting intensity equal to 130% of exercisers' estimated 1RM. Method: 70 healthy adults (age = 45.03 ± 25.64 y) with diverse RT experience were randomized into a reliability testing trial (RTT; n = 33) or an optimal method trial (OMT; n = 37). Subjects in the RTT performed either TDT or BT on 3 occasions separated by ≥ 72 hours, while subjects in the OMT performed each method once in random order on separate days. Results: No significant differences in percent coefficient of variation were observed between BT and TDT for either exercise used in the study (pneumatic seated chest press: Hedge's g = 0.25, p = .49; pneumatic recumbent leg press: Hedge's g = 0.12, p = .74). TDT was not found to produce significantly higher 1RM values than BT in any group. Conclusion: TDT does not appear to facilitate more reliable 1RM estimates than BT. Further research is needed to determine the stability of these findings across levels of exercisers' age, sex, and previous RT experience.

Impact of Spotter Sex on One Repetition Maximum Bench Press Performance

ABSTRACT

Nickerson, BS, Salinas, G, Garza, JM, Cho, S, and Snarr, RL. Impact of spotter sex on one repetition maximum bench press performance. J Strength Cond Res 35(9): 2397-2400, 2021-Resistance exercise is popular because of favorable health outcomes associated with increased muscular fitness. For these reasons, 1 repetition maximum (1RM), mean velocity (MV), and peak power (PP) are of interest during the bench press. However, research has yet to evaluate whether spotter sex impacts bench press performance. Therefore, the purpose of this study was to determine the impact of spotter sex on bench press performance during a 1RM testing protocol. Twenty resistance-trained individuals (10 men and 10 women) visited the laboratory on 2 separate occasions. Estimated 1RM was self-reported by subjects before the 1RM protocol. During their visits, subjects had their 1RM (kg), MV (m·s-1), and PP (W) determined on a bench press 1RM protocol while using a male or female spotter. Deception was used by telling subjects the intent of the study was to determine the reliability of a linear position transducer for measuring MV and PP during the 1RM trials. The main findings revealed that measured 1RM values for male weight lifters were significantly higher than estimated 1RM values when using both a male (p = 0.01) and female spotter (p < 0.01). In addition, results revealed MV and PP were significantly higher for the 1RM trials when male weight lifters had a male spotter (both p < 0.01). Alternatively, there were no significant differences in estimated vs. measured 1RM values for women as well as no effect of spotter sex on bench press strength (all p > 0.05). Practitioners should note that sex of a spotter does not seem to impact measured 1RM. However, notable influences may be observed within MV and PP.

Barbell velocity: a practical and precise method for predicting bench press strength in sedentary women

BACKGROUND

Bench press one-repetition maximum (BP1RM) prediction models offer a timely approach to predict BP1RM while avoiding the limitations with traditional BP1RM testing. Interestingly, no models have determined the ability for a traditional weight, the 20.5 kg barbell, to predict BP1RM strength. Few models have exclusively examined females and sedentary individuals, leaving the accuracy of these models unknown for these populations. Therefore, this investigation sought to examine the ability for 20.5 kg barbell velocity to predict BP1RM in sedentary females.

METHODS

Nineteen sedentary females (21.79±1.43 years, 166.08±7.76 cm, 63.98±7.54 kg, 31.57±4.72 BP1RM) completed BP1RM testing and completed two additional visits to determine 20.5 kg barbell velocity from a single repetition separated by 7-10 days. Nineteen additional females (21.39±1.09 years, 164.31±7.37 cm, 67.34±9.32 kg, 32.75±5.09 BP1RM) served as a cross-validating group completing identical testing procedures.

RESULTS

Regression analyses revealed that 20.5 kg barbell velocity accounted for 95% of the variance in BP1RM strength while presenting marginal standard error (1.34 kg) and mean absolute error (0.97 kg), with similar values observed in the cross-validating group (SEE: 2.13 kg, MAE: 1.56 kg). Predicted BP1RM values were not significantly different from actual BP1RM (P=0.43) nor were measures in barbell velocity between trials 1 and 2 (P=0.57), while displaying high reliability (ICC: 0.81). Measure bias between BP1RM methods was 0.449±1.651kg and the agreement between methods varied between -2.78 kg less and 0.3686 kg greater for 95% of the participants.

CONCLUSIONS

The present data provides an accurate prediction model regarding BP1RM for sedentary females. These findings can reduce the limitations associated with traditional BP1RM testing while providing a practical and accurate BP1RM approximation with marginal error.

Evaluation and comparison of electromyographic activity in bench press with feet on the ground and active hip flexion

The present study aimed to evaluate and compare the levels of electromyographic activation in the pectoralis major, anterior deltoid, triceps brachii, forearm, rectus abdominis, external oblique, and rectus femoris muscles during a horizontal bench press in two situations: 1) with the feet on the ground; and 2) with active hip flexion and 90° of knee flexion. Twenty young men were familiarized with the procedure and the calculation of one-rep max (1RM). In a second session, electromyographic activity values were recorded in both bench press situations (with the feet on the ground vs active hip flexion and knees at 90°) at 60% 1RM. Performing the bench press with the hips and knees flexed produced significantly greater muscle activation of all elevated muscles (p < 0.01; d > 0.5). The pectoralis major showed the greatest activation, followed by the anterior deltoid and the triceps brachii. In addition, the greater activation of the abdominal muscles occurs due to the need to stabilize the core while performing the bench press with hip and knee flexion as well as the lumbar spine due to traction of the hip flexors.

Resistance Training with Single vs. Multi-joint Exercises at Equal Total Load Volume: Effects on Body Composition, Cardiorespiratory Fitness, and Muscle Strength

The present study aimed to compare the effects of equal-volume resistance training performed with single-joint (SJ) or multi-joint exercises (MJ) on VO₂max, muscle strength and body composition in physically active males. Thirty-six participants were divided in two groups: SJ group (n = 18, 182.1 ± 5.2, 80.03 ± 2.78 kg, 23.5 ± 2.7 years) exercised with only SJ exercises (e.g., dumbbell fly, knee extension, etc.) and MJ group (n = 18, 185.3 ± 3.6 cm, 80.69 ± 2.98 kg, 25.5 ± 3.8 years) with only MJ exercises (e.g., bench press, squat, etc.). The total work volume (repetitions × sets × load) was equated between groups. Training was performed three times a week for 8 weeks. Before and after the training period, participants were tested for VO₂max, body composition, 1 RM on the bench press, knee extension and squat. Analysis of covariance (ANCOVA) was used to compare post training values between groups, using baseline values as covariates. According to the results, both groups decreased body fat and increased fat free mass with no difference between them. Whilst both groups significantly increased cardiorespiratory fitness and maximal strength, the improvements in MJ group were higher than for SJ in VO₂max (5.1 and 12.5% for SJ and MJ), bench press 1 RM (8.1 and 10.9% for SJ and MJ), knee extension 1 RM (12.4 and 18.9% for SJ and MJ) and squat 1 RM (8.3 and 13.8% for SJ and MJ). In conclusion, when total work volume was equated, RT programs involving MJ exercises appear to be more efficient for improving muscle strength and maximal oxygen consumption than programs involving SJ exercises, but no differences were found for body composition.