Generality versus Specificity in strength testing. EJAP (original) (raw)
Related papers
Muscle Strength And Size Correlations At Baseline And Following Unilateral Resistance Training
Medicine & Science in Sports & Exercise, 2020
Traditional theory has linked muscular size and muscular strength at baseline and following resistance training, though recent studies have challenged the independence of these traits, especially within the context of chronic resistance training. We previously completed a large study of strength and size changes with 12 weeks of progressive resistance training in previously untrained adults. PURPOSE: We examined the effects of progressive resistance training on the relationship between muscle volume (VOL) and muscle strength, measured as both dynamic (one repetition maximum; 1-RM) and isometric (maximal voluntary contraction; MVC) strength. We further tested for sex differences in these relationships. METHODS: 665 healthy young (18>age>40) and untrained individuals (254 men and 411 women) were tested. Muscle volume (by magnetic resonance imaging) and strength (1-RM and MVC) measures were taken before and after 12-weeks of resistance training of the non-dominant biceps/triceps. Subjects trained with progressively increasing weights twice per week using biceps preacher curl, biceps concentration curl, standing biceps curl, overhead triceps extension, and triceps kickback. We used Pearson correlations to test strength-size relationships in the entire cohort and within sex both at baseline and percent change following training. RESULTS: Weak to moderate correlations were seen at baseline: VOL-1-RM (r=0.43 in all, 0.32 in women and 0.14 in men, all p<0.01) and VOL-MVC (r=0.34 in all, 0.19 in women and 0.28 in men, all p<0.01). Following training, specific relationships between percent changes in strength and size were: VOL-1-RM (r=0.04 in all, p=0.3; 0.13 in women, p=0.006; and 0.14 in men, p=0.03) and VOL-MVC (r=0.13 in all, p<0.01; 0.19 in women, p<0.01; and 0.12 in men, p=0.054). CONCLUSION: At baseline, significant but weak correlations exist between strength and size, regardless of sex. Following training, correlations became weaker, and even insignificant for change in volume to change in 1-RM in the whole cohort and change in volume to change in MVC in men. Together, these data provide evidence that isometric and dynamic strength are complex traits, especially following resistance training, that are affected by factors beyond size.
Isometric strength and its relationship to dynamic performance: A Systematic Review
2010
Strength is a fundamental quality necessary in achieving optimal physical function and is defined as the ability to produce more force.(Siff M; Stone MH et al., 1993). Thus the display of strength has characteristics which include a magnitude, rate and direction. The force production can be measured by isotonic, isometric or isokinetic methods. The isotonic techniques require lifting a particular weight through a fixed number of repetitions such as 1RM testing or using prediction equations (Bryzcki, 1993). The Isokinetic measurements involve the use of isokinetic devices. The isometric testing is done by a maximal voluntary contraction performed at a specific angle against an unyielding resistance which in series with a strain gauge, cable tensiometer, force platform or similar device whose transducer measures the applied force (Stone et al., 2002).
Journal of Strength and Conditioning Research, 2016
The muscle strength capacities to exert force under various movement conditions have been indiscriminately assessed from various strength tests and variables applied on different muscles. We tested the hypotheses that the distinctive strength capacities would be revealed (H1) through different strength tests, and (H2) through different strength variables. Alternatively, (H3) all strength variables independently of the selected test could depict the same strength capacity of the tested muscle. Sixty subjects performed both the standard strength test and the test of alternating contractions of 6 pairs of antagonistic muscles acting in different leg and arm joints. The dependent variables obtained from each test and muscle were the maximum isometric force and the rate of force development. A confirmatory principle component analysis set to 2 factors explained 31.9% of the total variance. The factor loadings discerned between the tested arm and leg muscles, but not between the strength tests and variables. An exploratory analysis applied on the same data revealed 6 factors that explained 60.1% of the total variance. Again, the individual factors were mainly loaded by different tests and variables obtained from the same pair of antagonistic muscles. Therefore, a comprehensive assessment of the muscle strength capacity of the tested individual should be based on a single strength test and variable obtained from a number of different muscles, rather than on a single muscle tested through different tests and variables. The selected muscles should act in different limbs and joints, while the maximum isometric force should be the variable of choice.
Relationships among the muscle strength properties as assessed through various tests and variables
Journal of Electromyography and Kinesiology, 2013
We tested the hypotheses that the individual strength properties depend on the applied test and the variable extracted, rather than on the muscle group tested. Flexor and extensor muscles acting in the knee and elbow joint were tested in 58 participants. The standard strength test (SST; based on sustained maximum contraction) and alternating consecutive maximum contractions (ACMC; alternating contractions of antagonistic muscles) performed under static conditions were separately applied to provide the maximum force (F) and the rate of force development (RFD) of each tested muscle. The principal component analysis applied on all 16 variables revealed 3 factors that explained 85.5% of the total variance. Contrary to our hypotheses, the individual factors were loaded with the variables recorded from individual muscles, rather than with either the particular variables or tests. The present findings suggest that recording both F and RFD in routine strength testing procedures could be redundant since they may assess the same strength property of the tested muscle. In addition, ACMC may be a feasible alternative to SST since it could assess the same strength properties from two antagonist muscles through a single trial, while being based on relatively low and transient forces.
International journal of exercise science, 2018
The influence of baseline strength or muscle size on adaptations to training is not well-understood. Comparisons between novice and advanced lifters, and between stronger and weaker experienced-lifters, have produced conflicting results. This study examined the effect of baseline muscle strength and size on subsequent adaptations in resistance-trained individuals following a traditional high-volume, short-rest resistance training protocol. Fourteen resistance-trained men (24.0±2.7 y; 90.1±11.7 kg; 169.9±29.0 cm) completed pre-training (PRE) ultrasound measurements of muscle cross-sectional area (CSA) in the rectus femoris (RF), vastus lateralis (VL), pectoralis major, and triceps brachii (TRI) prior to strength assessments (e.g., one-repetition maximum strength bench press and back-squat). Post-training (POST) assessments were completed following 8-wks (4 d·wk) of resistance training. Comparisons were made between stronger (STR) and weaker (WKR) participants, and between larger (LGR...
The Journal of Sports Medicine and Physical Fitness, 2020
The purpose of this article was to review the data on the relationship between multi-joint isometric strength test (IsoTest) force-time characteristics (peak force, rate of force development and impulse) and dynamic performance that is available in the current literature. Four electronic databases were searched using search terms related to IsoTest. Studies were considered eligible if they were original research studies that investigated the relationships between multi-joint IsoTest and performance of dynamic movements; published in peer-reviewed journals; had participants who were athletes or active individuals who participate in recreational sports or resistance training, with no restriction on sex; and had full text available. A total of 47 studies were selected. These studies showed significant small to large correlations between isometric bench press (IBP) force-time variables and upper body dynamic performances (r 2 = 0.221 to 0.608, p < 0.05) and significant small to very large correlation between isometric squat (ISqT) (r 2 = 0.085 to 0.746, p < 0.05) and isometric mid-thigh pull (IMTP) (r 2 = 0.120 to 0.941, p < 0.05) force-time variables with lower body dynamic performances. IsoTest force-time characteristics were shown to have small to very large correlations with dynamic performances of the upper and lower limbs as well as performance of sporting movements (r 2 = 0.118 to 0.700, p < 0.05). These data suggest that IsoTest force-time characteristics provide insights into the force production capability of athletes which give insight into dynamic performance capabilities.
Research in Sports Medicine, 2020
Although used by resistance-trained individuals, it is unknown if increasing muscle strength prior to hypertrophy training leads to greater muscle growth and strength gains. We investigated muscle thickness and maximum strength in 26 resistance-trained men who were randomly assigned to either: STHT, consisted in a 3-week strength-oriented training period (4x1-3 repetition maximum [RM]) prior to a 5-week hypertrophy-oriented period (4x8-12RM), or HT, which comprised an 8-week hypertrophy-oriented training period. Vastus lateralis muscle thickness, and back squat and legpress 1-RM were assessed at pre, third week, and after 8 weeks of training. When pre-to-post changes are compared, STHT induced greater muscle growth (p = 0.049; 95%CI = 0.15-3.2%; d = 0.81) and strength gains in the back squat (p = 0.015; 95%CI = 1.5-13%; d = 1.05) and leg-press 45° (p = 0.044; 95%CI = 0.16-9.9%; d = 0.79) compared to HT. Our results support the use of a period to increase muscle strength prior to an HT to increase muscle thickness and maximum strength in resistance-trained men.
Reliability of an Isokinetic Test of Muscle Strength and Endurance
Journal of Orthopaedic & Sports Physical Therapy, 1989
The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330°/sec) and a muscle endurance test (number of contractions performed in 45 sec at 180°/sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.
Reliability of an Isokinetic Test of Muscle Strength and Endurance 1
Journal of Orthopaedic & Sports Physical Therapy, 1989
The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330°/sec) and a muscle endurance test (number of contractions performed in 45 sec at 180°/sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.