Absolute Muscular Strength Research Articles

Sex differences in human performance.

Sex as a biological variable is an underappreciated aspect of biomedical research, with its importance emerging in more recent years. This review assesses the current understanding of sex differences in human physical performance. Males outperform females in many physical capacities because they are faster, stronger and more powerful, particularly after male puberty. This review highlights key sex differences in physiological and anatomical systems (generally conferred via sex steroids and puberty) that contribute to these sex differences in human physical performance. Specifically, we address the effects of the primary sex steroids that affect human physical development, discuss insight gained from an observational study of 'real-world data' and elite athletes, and highlight the key physiological mechanisms that contribute to sex differences in several aspects of physical performance. Physiological mechanisms discussed include those for the varying magnitude of the sex differences in performance involving: (1) absolute muscular strength and power; (2) fatigability of limb muscles as a measure of relative performance; and (3) maximal aerobic power and endurance. The profound sex-based differences in human performance involving strength, power, speed and endurance, and that are largely attributable to the direct and indirect effects of sex-steroid hormones, sex chromosomes and epigenetics, provide a scientific rationale and framework for policy decisions on sex-based categories in sports during puberty and adulthood. Finally, we highlight the sex bias and problem in human performance research of insufficient studies and information on females across many areas of biology and physiology, creating knowledge gaps and opportunities for high-impact studies.

The Value of Strength as a Predictor of Musculoskeletal Injury in Canadian Armed Forces Basic Infantry Candidates.

Musculoskeletal injuries (MSKI) impact military organizations by threatening their operational readiness, warranting investigation into relevant factors to inform risk reduction strategies. While several self-reported and physical performance measures have been associated with MSKI among military personnel, few have been validated and none have been reported in Canadian basic infantry candidates. The purpose of this study was to investigate associations between self-reported and physical performance measures and MSKI, and determine their validity as predictors of MSKI, in Canadian basic infantry candidates. This was a planned secondary analysis of a study tracking MSKI at a basic infantry training facility in Ontario, Canada approved by Defence Research & Development Canada. Before the basic infantry training, consenting candidates completed a baseline testing session including self-reported questionnaires, measures of anthropometry, and physical performance previously associated with MSKI (ankle dorsiflexion test, Y-Balance Test, Isometric Mid-Thigh Pull, and the Fitness for Operational Requirements of CAF Employment (FORCE) evaluation). All MSKI reported by candidates were diagnosed by licensed healthcare providers. From a total sample of 129 candidates, 76% (n = 98) were used to determine any associations between baseline testing variables and MSKI and to develop a predictive model (Development Sample), while 24% (n = 33) were used to offer preliminary validation of the same predictive model (Validation Sample). The binary logistic regression and independent sample t-testing determined independent associations with MSKI in the Development Sample. All continuous variables and dichotomous variables previously associated with MSKI risk (Smoker Yes/No, previous history of MSKI, and physical inactivity) were entered into a backward stepwise logistic regression analysis to assess the predictive association with MSKI incidence in the Development Sample. The regression model was then applied to the Validation Sample. A total of 35 MSKI were diagnosed by Health Services Centre staff. The majority of the MSKI were acute (63%), sustained to the hip, knee, and ankle (74%). The most common diagnoses were strains and sprains (71%). Uninjured participants performed significantly better on the Relative Isometric Mid-Thigh Pull, FORCE 20 mR, FORCE ILS, and FORCE Estimated VO2peak compared to injured participants. Logistic regression analysis showed that the only variable with significant independent association with diagnosed MSKI incidence was self-reported previous history of MSKI. However, the backward stepwise logistic regression analysis retained self-reported previous history of MSKI, FORCE SBD, FORCE Estimated VO2peak, and Isometric Mid-Thigh Pull Peak Force as predictors of MKSI. The logistic regression model including these variables could predict MSKI with an accuracy of 79% in the Development Sample and 67% in the Validation Sample. This study provides preliminary support for the value of measures of absolute muscular strength and cardiorespiratory fitness as predictors of MSKI in Canadian basic infantry candidates. Given the associations between physical performance measures and MSKI, and their necessity during occupational tasks, it is recommended that Canadian basic infantry training facilities integrate resistance training with external loads to best prepare their candidates to meet their occupational demands and potentially minimize MSKI. Further investigations to confirm the predictive capacity of these variables in a larger sample across additional facilities are warranted.

Physical fitness in Austrian elementary school children prior to and post-COVID-19.

With the emergence of the COVID-19 pandemic, many countries implemented policies that included movement restrictions, social distancing and school closures in order to control the spread of the virus. Even though these actions may have been necessary to save lives, there have been some unintended consequences that could affect future public health. The present study uses data from more than 24,500 Austrian elementary school children (51.2% male) that participated in a state-wide fitness evaluation program, which was initiated in the 2016/17 school year. In addition to body weight and height, data on cardiorespiratory endurance, muscular power, speed, agility, flexibility and object control were collected from three cohorts prior to the implementation of movement restrictions (school years: 2016/17, 2017/18, 2018/19) and one cohort in 2022, after the majority of COVID-19 policies had been lifted. Body mass index percentiles were significantly higher in children post-COVID-19 (p < 0.01). Further, cardiorespiratory endurance, agility and flexibility were significantly lower post-COVID-19 compared to the years preceding movement restrictions (p ≤ 0.01), while absolute muscular strength was higher in the year 2022 (p < 0.01). Given the detrimental effects of COVID-19 policies on physical fitness in children, additional efforts are necessary that include versatile opportunities for physical activity and the promotion of physical fitness in order to modify the observed negative health trajectories and ensure future public health.

Evaluating physical fitness and the relationship between field and non-field tests in male rugby academy players based on playing position.

Rugby is a globally played sport with statistically significant variance in the physical fitness levels of rugby players in different playing positions. The aim of the study was to evaluate the physical fitness levels in rugby academy players and to determine the relationship between non-field and field tests based on the forward and backline playing positions. The study made use of cross-sectional, secondary data and employed a quantitative and correlational research design. Forty-five rugby academy players from a rugby academy in the Western Province were conveniently recruited for the study and split into forward and backline playing positions. The non-field tests were stature, body mass, and body fat percentage, bench-press, pull-ups, and vertical jump, while the field tests were the10-m, 30-m, and 40-m sprints, the Broncho Test, and the repeat sprintability test. Data analysis comprised independent samples t-test, Pearson's correlation, and linear and logistic regression analysis. The level of statistical significance was set at P<0.05. Forwards were significantly heavier, stronger and more powerful than backline players (P<0.05). Backline players had a lower body fat percentage, were faster, and had a higher anaerobic endurance capacity, and higher muscular endurance (P<0.05). Body mass, body fat percentage, aerobic capacity, absolute muscular power, and relative muscular strength were all significant predictors of speed (P<0.01), and body mass was a significant predictor of anaerobic capacity (P<0.05). Forwards had higher absolute muscular strength and peak power output, whereas backs were significantly lighter, faster, relatively stronger, and possessed higher muscular endurance and were significantly influenced, in particular, by body composition and aerobic capacity.

Lower Limb Strength Profile in Elderly with Different Pathologies: Comparisons with Healthy Subjects.

Sarcopenia and muscle strength reduction are a frequent disorder in non-communicable chronic diseases. The aims of this study are: (a) to verify if the absolute and relative to body weight muscle strength of lower limb is affected by the presence of pathology; (b) to verify if the trends are different among knee and ankles joints. One-hundred and forty-five elderly were recruited (16 liver transplant recipients, 48 kidney transplant recipients, 52 elderly with obesity, 30 healthy elderly). Muscular strength of lower limb was evaluated. Evaluation protocol included maximal isometric knee extension, maximal isokinetic knee extension and flexion, maximal isokinetic ankle (both right and left) extension and flexion. A statistically significant interaction between measurement and group membership was found for absolute strength measure (F (4.23, 170.56) = 3.316, p = 0.011, partial η2 (η2p) = 0.076), and relative strength measure(F (4.44, 174.72) = 16.407, p < 0.01, partial η2 (η2p) = 0.294). Elderly patients living with kidney transplants showed the lower level of absolute muscular strength, while relative muscular strength is mainly lacking in the elderly with obesity. The strength profile of elderly subjects is affected by obesity, liver transplantation, and kidney transplantation.

Вплив рівня розвитку абсолютної сили на показники технічної підготовленості штовхальників ядра на етапі спеціалізованої базової підготовки

The results of the researches of influence of indicators of absolute force on parameters of technical preparedness of the qualified shot putters are presented. Purpose: to investigate influence of the level of development of absolute force on indicators of technical preparedness of the qualified shot putters. Material & Methods: analysis and generalization of scientific and methodical literature, pedagogical testing, video filming with the subsequent biomechanical analysis, methods of mathematical statistics. 12 qualified shot putters participated in the research. Results: the high correlation interrelation between the level of development of absolute force and separate indicators of technical preparedness of shot putters is revealed. Conclusions: technical preparedness of shot putters farthest depends on the level of development of absolute muscular strength of legs, chest and hands, in particular, triceps .

Is muscle strength ratio a criterion for diagnosis of site-specific muscle loss?

Recently, data have questioned the homogenous model of sarcopenia, and suggest that the loss of muscle mass could occur in a site-specific manner. It is unclear, however, whether a muscle strength ratio can be used to assess age-related, site-specific muscle loss. The purpose of the present study was to investigate the relationship between the age-related loss of thigh muscle, muscle function and gait performance. A total of 55 men aged 18-79 years had muscle thickness (MTH) measured by ultrasound at three sites on the anterior (30% and 50% of thigh length) and posterior (70% of thigh length) aspects of the thigh. MTH ratios were calculated to assess the site-specific muscle loss (anterior 30% : posterior 70% MTH [A30:P70] and anterior 50% :posterior 70% MTH [A50:P70]). Walking performance, maximum isometric knee extension/flexion, toe-grasping and handgrip strength were measured. Age was inversely correlated with the ratios of A30:P70 (r=-0.332) and A50:P70 (r=-0.466). There were no significant correlations between the A30:P70 and A50:P70 ratios, and height and bodyweight. The A30 : P70 and A50 : P70 ratios were also not correlated with maximal walking speed. However, the A50:P70 ratio was significantly correlated with zig-zag walking (r=-0.350) and handgrip strength (r=0.334). In addition, these MTH ratios were also correlated with knee extension (r=0.309 and r=0.405), flexion (r=0.306 and r=0.412) and toe-grasping strength (r=0.265 and r=0.336). After adjusting for physical activity, the MTH ratios were still not correlated with ratio of muscle strength. Strength ratios did not correlate with MTH ratios. Our cross-sectional analysis suggests that age-related site-specific muscle loss could assess the decrease in absolute muscular strength, but not the ratio of muscle strength.

A Comparison of Absolute, Ratio and Allometric Scaling Methods for Normalizing Strength in Elite American Football Players

A Comparison of Absolute, Ratio and Allometric Scaling Methods for Normalizing Strength in Elite American Football Players Division I football players exemplify the greatest range in body mass of any modern team sport. Body mass may differ by over 80 kg between the various positions. Absolute muscular strength is typically greater in larger individuals, but such data does not allow for accurate comparisons. Therefore, in order to compare the performance indices of individual groups allometric rather than ratio scaling has been suggested. The purpose of this study was to compare absolute strength, normalized ratio and allometrically scaled data among players of different size.

Hand-Grip Strength as a Predictor of Muscular Strength and Endurance

PURPOSE: Several fitness tests are commonly administered to determine either muscular strength or endurance. Even though an ample number of tests exist to measure upper body muscular endurance and lower body maximal muscular strength, a single test that assesses both could be beneficial in some circumstances. The purpose of this study was to determine if a hand-grip dynamometer test is a valid predictor of both muscular strength and endurance. METHODS: Participants included 54 college-aged students (age 21.88 ± 2.1 yrs, height 168.7 ± 9.4 cm, weight 68.0 ± 14.0 kg). Subjects performed the following tests of muscular strength and endurance: a one minute pushup test (PU), one minute bent knee sit-ups (SU), ninety second dumbbell swing (DBS), 1RM leg extension (1RM LE), 1RM leg press (1RM LP), and hand grip dynamometer test (HGD). A Keiser pneumatic resistance machine was used to measure maximal strength for the 1RM tests. Subjects performed 3 trials of the HGD test, after which the maximum value was recorded. Pearson bivariate correlation analyses were used to determine relationships between measures. RESULTS: Significant correlations were found between HGD and SU (r = .472, p≤.001), HGD and PU (r = .241, p = .047), HGD and 1RM LE (r = .718, p≤.001), HGD and 1RM LP (r = .609, p≤.001). CONCLUSIONS: The hand grip dynamometer test was a predictor of both absolute muscular strength and endurance. The correlations calculated implicate its usefulness as a method to predict both muscular strength and endurance in a simple fashion. PRACTICAL APPLICATIONS: The results are applicable to anyone interested in testing muscular strength and endurance in group settings; or with special populations. The predictive value of the HGD could serve as a useful tool to predict muscular strength and endurance that would normally require more complex assessment. HGD testing requires only a single piece of equipment and minimal effort from subjects who may be unwilling or unable to perform the other more strenuous tests.

Muscular fitness, body composition and physical self-perception in adolescents

The primary aim of this study was to investigate gender differences in the relationship between muscular strength, body composition, and physical self-perception in adolescents. Participants ( n = 106, age 15.0 ± 0.7 years, 51% boys) completed the following assessments: height and weight, bio-electrical impedance analysis (body fat %), muscular strength (1RM bench press and leg press), and the Children's Physical Self-Perception Profile. Bivariate correlations were examined and mediation analysis was used to explore if physical self-perception sub-domains mediated the relationship between muscular strength/adiposity and overall physical self-worth. Among boys, physical self-worth was associated with absolute total strength ( r = 0.36, p < 0.01), but not with body fat % ( r = −0.11, p = 0.44), or relative total strength ( r = 0.21, p = 0.13). In adolescent girls, physical self-worth was associated with body fat % ( r = −0.42, p < 0.01), relative total strength ( r = 0.40, p < 0.01) but not absolute total strength ( r = 0.07, p = 0.62). In boys, perceived physical strength mediated the relationship between absolute muscular strength and physical self-worth. Relative muscular strength was not associated with perceived strength ( p > 0.05) in girls and the test of the mediated effect was non-significant ( p > 0.05). Perceived body attractiveness was found to mediate the relationship between body fat % and physical self-worth among boys and girls. Physical self-worth is associated with different components of health-related fitness in adolescent girls and boys. Mediation analysis can be used to provide insights into the complex interrelationships between variables.

Rest Interval between Sets in Strength Training

Strength training has become one of the most popular physical activities for increasing characteristics such as absolute muscular strength, endurance, hypertrophy and muscular power. For efficient, safe and effective training, it is of utmost importance to understand the interaction among training variables, which might include the intensity, number of sets, rest interval between sets, exercise modality and velocity of muscle action. Research has indicated that the rest interval between sets is an important variable that affects both acute responses and chronic adaptations to resistance exercise programmes. The purpose of this review is to analyse and discuss the rest interval between sets for targeting specific training outcomes (e.g. absolute muscular strength, endurance, hypertrophy and muscular power). The Scielo, Science Citation Index, National Library of Medicine, MEDLINE, Scopus, Sport Discus and CINAHL databases were used to locate previous original scientific investigations. The 35 studies reviewed examined both acute responses and chronic adaptations, with rest interval length as the experimental variable. In terms of acute responses, a key finding was that when training with loads between 50% and 90% of one repetition maximum, 3-5 minutes' rest between sets allowed for greater repetitions over multiple sets. Furthermore, in terms of chronic adaptations, resting 3-5 minutes between sets produced greater increases in absolute strength, due to higher intensities and volumes of training. Similarly, higher levels of muscular power were demonstrated over multiple sets with 3 or 5 minutes versus 1 minute of rest between sets. Conversely, some experiments have demonstrated that when testing maximal strength, 1-minute rest intervals might be sufficient between repeated attempts; however, from a psychological and physiological standpoint, the inclusion of 3- to 5-minute rest intervals might be safer and more reliable. When the training goal is muscular hypertrophy, the combination of moderate-intensity sets with short rest intervals of 30-60 seconds might be most effective due to greater acute levels of growth hormone during such workouts. Finally, the research on rest interval length in relation to chronic muscular endurance adaptations is less clear. Training with short rest intervals (e.g. 20 seconds to 1 minute) resulted in higher repetition velocities during repeated submaximal muscle actions and also greater total torque during a high-intensity cycle test. Both of these findings indirectly demonstrated the benefits of utilizing short rest intervals for gains in muscular endurance. In summary, the rest interval between sets is an important variable that should receive more attention in resistance exercise prescription. When prescribed appropriately with other important prescriptive variables (i.e. volume and intensity), the amount of rest between sets can influence the efficiency, safety and ultimate effectiveness of a strength training programme.

Muscular Power, Neuromuscular Activation, and Performance in Shot Put Athletes At Preseason and at Competition Period

The aim of this study was to investigate changes in shot put performance, muscular power, and neuromuscular activation of the lower extremities, between the preseason and the competition period, in skilled shot put athletes using the rotational technique. Shot put performance was assessed at the start of the pre-season period as well as after 12 weeks, at the competition period, in nine shot putters. Electromyographic (EMG) activity of the right vastus lateralis muscle was recorded during all shot put trials. Maximum squat strength (1RM) and mechanical parameters during the countermovement jump (CMJ) on a force platform were also determined at pre-season and at competition period. Shot put performance increased 4.7% (p < 0.05), while 1RM squat increased 6.5% (p < 0.025). EMG activity during the delivery phase was increased significantly (p < 0.025) after the training period. Shot put performance was significantly related with muscular power and takeoff velocity during the CMJ, at competition period (r = 0.66, p < 0.05 and 0.70, p < 0.05), but not with maximum vertical force. One RM squat was not related significantly with shot put performance. These results suggest that muscular power of the lower extremities is a better predictor of rotational shot put performance than absolute muscular strength in skilled athletes, at least during the competition period.

Does muscular weakness account for younger children's enhanced force variability?

This study examined the degree to which younger children's greater variability in force control is associated with muscular weakness. Children aged 6, 8, and 10 years and adults aged 18-22 years produced isometric force via index finger metacarpo-phalangeal joint flexion to varying force levels (5%, 15%, 25%, and 35% maximal voluntary contraction). The force output of the younger children was more variable and had greater time dependent structure compared to that of the adults at all force levels. However, the effect of age on variability was significantly reduced, but not eliminated when absolute muscular strength was taken into account. It is concluded that age-related changes in children's force control result from a multitude of developmental processes including increases in muscular strength.

THE CONTRIBUTION OF MAXIMAL FORCE PRODUCTION TO EXPLOSIVE MOVEMENT AMONG YOUNG COLLEGIATE ATHLETES

Critical to multidimensional sport conditioning is a systematic knowledge of the interactions between fitness components, as well as the transference relationships to performance. The purpose of this investigation was to examine the relationships between lower body muscular strength and several fundamental explosive performance measures. Fifty-four men and women collegiate athletes were tested to determine (a) lower-body muscular strength (1 repetition maximum barbell back squat), (b) countermovement vertical jump height and peak power output, (c) standing broad jump distance, (d) agility (cone T-test time), (e) sprint acceleration (m·s−2), and (f) sprint velocity (m·s−1). Analyses were performed using Pearson r correlations to examine these relationships. Partial correlations tested for relationships between performance measures while controlling for muscular strength. T-tests were performed to assess the difference between men and women. Correlation data demonstrated that significant (p < 0.01) strong linear relationships were indicated between muscular strength and power, as well as every sport-performance field tests. However, when controlling for strength with partial correlation, each of these relationships appreciably diminished. Significant differences (p < 0.05) were found between men and women for each of the performance tests. Muscular strength, peak power output, vertical jumping ability, standing broad jump, agility, sprint acceleration, and sprint velocity were all shown to be very highly related. Further examination demonstrated that body mass–adjusted muscular strength is more highly related to performance measures than is absolute muscular strength. Current correlation data provide a quantified look at the interaction between muscular fitness components, as well as the transfer relationship to several athletic-specific performance measures.

The Contribution of Maximal Force Production to Explosive Movement Among Young Collegiate Athletes

Critical to multidimensional sport conditioning is a systematic knowledge of the interactions between fitness components, as well as the transference relationships to performance. The purpose of this investigation was to examine the relationships between lower body muscular strength and several fundamental explosive performance measures. Fifty-four men and women collegiate athletes were tested to determine (a) lower-body muscular strength (1 repetition maximum barbell back squat), (b) countermovement vertical jump height and peak power output, (c) standing broad jump distance, (d) agility (cone T-test time), (e) sprint acceleration (m.s(-2)), and (f) sprint velocity (m.s(-1)). Analyses were performed using Pearson r correlations to examine these relationships. Partial correlations tested for relationships between performance measures while controlling for muscular strength. T-tests were performed to assess the difference between men and women. Correlation data demonstrated that significant (p < 0.01) strong linear relationships were indicated between muscular strength and power, as well as every sport-performance field tests. However, when controlling for strength with partial correlation, each of these relationships appreciably diminished. Significant differences (p < 0.05) were found between men and women for each of the performance tests. Muscular strength, peak power output, vertical jumping ability, standing broad jump, agility, sprint acceleration, and sprint velocity were all shown to be very highly related. Further examination demonstrated that body mass-adjusted muscular strength is more highly related to performance measures than is absolute muscular strength. Current correlation data provide a quantified look at the interaction between muscular fitness components, as well as the transfer relationship to several athletic-specific performance measures.

Yearly Changes in the Body Composition and Muscular Strength of High School Wrestlers

Abstract The purpose of this investigation was to determine the yearly changes in body composition as well as absolute and relative isokinetic forearm flexion and extension strength of high school wrestlers. Evaluations of body composition (underwater weighing) were performed on 27 high school wrestlers prior to three consecutive seasons. In addition, isokinetic forearm flexion and extension strength values at 180°/s (Cybex II) were available for 20 of the subjects. The mean ages at the times of laboratory testing were 15.5 (± .5), 16.5 (± .5), and 17.5 (± .5) years. Repeated measures ANOVA or ANCOVA with Tukey post-hoc comparisons were used to locate significant (p<.05) differences across age for height, body weight, relative fat, body density, fat weight, fat-free weight, absolute muscular strength, and muscular strength covaried for body weight and fat-free weight. There were yearly increases in all variables except fat weight, forearm flexion covaried for fat-free weight and forearm extension covaried...