The main objective of this study was to determine the differences in energy expenditure (EE) according to sex during and after two different squat training protocols in a group of healthy young adults. Twenty-nine Sports Sciences students volunteered to participate in this study. They attended the laboratory on four different days and completed four sessions: two sessions with 3 sets of 12 repetitions at 75% of their one-repetition maximum (RM) and two sessions with 3 sets of 30 repetitions at 50% of their 1RM. Energy expenditure was evaluated using an indirect calorimeter. Males consistently demonstrated higher EE in all sessions and intensities. The linear regression model identified a significant association between sex, BMI, and total EE across all sessions and intensities. In conclusion, males exhibited higher EE in both protocols (50% and 75% of 1RM) throughout all sessions. Furthermore, sex and BMI were found to influence EE in healthy young adults. Therefore, coaches should consider sex when assessing EE, as the metabolic response differs between males and females.

Background: the main objective of this study was to evaluate the test-retest reliability of two different functional electromechanical dynamometry (FEMD)-controlled squat training protocols. Methods: twenty-eight healthy young adults volunteered to participate in this study. They attended the laboratory on four different days and performed four sessions: two of three sets of 12 repetitions at 75% 1RM and two of three sets of 30 repetitions at 50% 1RM. The range of movement (ROM), mean dynamic strength (MDS), peak dynamic strength (PDS), mean velocity (MV), peak velocity (PV), mean potency (MP), peak potency (PP), work (W), and impulse (I) were recorded. To evaluate the reliability of FEMD, the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV) were obtained. Results: reliability was very high for ROM (CV: 3.72%, ICC: 0.95), MDS (CV: 1.09%, ICC: 1.00), PDS (CV: 1.97%, ICC: 1.00), and W (CV: 4.69%, ICC: 1.00) conditions at 50% 1RM and for ROM (CV: 3.90%, ICC: 0.95), MDS (CV: 0.52, ICC: 1.00), PDS (CV: 1.49%, ICC: 0.98), and W (CV: 4.14%, ICC: 1.00) conditions at 75% 1RM and high for the rest of variables at 50 and 75% 1RM. Conclusions: this study demonstrates that FEMD is a reliable instrument to measure ROM, MDS, PDS, MV, PV, PV, MP, MP, W, and I during both squat protocols (50 and 75% 1RM) in healthy young adults.

Background: A method to assess the influence of sex and side testing on trunk rotator muscles has not been described. The purpose was to analyze the influence of sex and dominant and non-dominant sides (DS-NDS) on the reliability of two trunk rotator exercises and to study the relationship between the DS-NDS of two trunk rotator strength exercises. Methods: The reliability of the horizontal cable woodchop (HCW) and low cable woodchop (LWC) exercises was studied using a test-retest design with 51 physically active students. Isokinetic and isometric strength were assessed with a functional electromechanical dynamometer. Results: There were significant differences in reliability between male and female HCW and no significant differences in reliability between the average of the DS-NDS in HCW and LCW. There were no significant differences between the DS-NDS in the sex of HCW, and the strength of the two exercises showed no significant differences except for two conditions assessed. Very large to extremely large correlations were observed between sides in the strength of two exercises (r = 0.71–0.91). Conclusions: This test is handy for physical trainers or coaches to know the strength of the trunk rotators of their athletes.

Background: Trunk rotator strength plays an important role in sports performance and health. A reliable method to assess these muscles with functional electromechanical dynamometer has not been described. Therefore, the objectives of this paper were (I) to explore the reliability of different strength variables collected in isokinetic and isometric conditions during two trunk rotator exercises, and (II) to determine the relationship of isometric and dynamic strength variables collected in the same exercise. Methods: A repeated measures design was performed to evaluate the reliability of the horizontal cable woodchop (HCW) and low cable woodchop (LCW) exercises. Reliability was assessed using t-tests of paired samples for the effect size, the standard error of measurement, the coefficient of variation (CV) and the intraclass correlation coefficient (ICC). The Pearson’s (r) correlation coefficient was used to explore the association between isometric and isokinetic tests. Results: HCW exercise is more reliable than LCW exercise in assessing trunk rotator muscles. The strength manifestation that should be used is the average strength, and the most reliable evaluation was the HCW at 0.40 m·s⁻¹ concentric (ICC = 0.89; CV = 10.21%) and eccentric (ICC = 0.85; CV = 9.33%) contraction and the dynamic condition that most correlated with the isometric was LWC at 0.50 m·s⁻¹ (r = 0.83; p < 0.01). Conclusion: HCW is a reliable exercise to measure trunk rotator muscles.

Context: Current devices to assess strength performance in handball may not be sufficiently sports-specific and reliable methods. Functional electromechanical dynamometry is a new technology that allows the development of accurate strength tests in athletes. Purpose: To determine the absolute and relative reliability and to compare the reliability of the right and left side, and mean and peak force of 3 specific strength tests in handball players with a functional electromechanical dynamometer: unilateral pullover, standing lift, and step forward. Methods: Fourteen male handball players of the first Spanish division (28.79 [4.81] y; 10.38 [4.63] y of professional experience) performed a repeated-measurement design. Three testing sessions were performed (one per week). The first measurement consisted of 4 isometric tests (right and left unilateral pullover, and right and left standing lift) to obtain isometric peak force, and in the second and third sessions, 6 incremental tests until failure (right and left unilateral pullover, and right and left standing lift, right and left step forward) were performed. Results: The tests provided high reliability or acceptable reliability for mean and peak strength of unilateral pullover, standing lift and step forward (intraclass correlation coefficient = .83–.97; coefficient of variation = 3.90–11.57). Effect side was negligible in any of the parameters, except for a small effect side in the left peak force for unilateral pullover and a small effect side on the left side for a step forward. Significant differences in reliability (coefficient of variation ratio > 1.15) were found between the right and left sides and peak and mean force in all exercises except peak force in unilateral pullover and step forward. Conclusion: These results confirm that the tests could be applied to assess physical performance in handball at the same time as regular gym training. Moreover, this is an excellent opportunity to individualize the player’s weekly load.

Article: Influence of trunk rotator strength on rotational medicine ball throwing performance - The Journal of Sports Medicine and Physical Fitness 2023 Sep 18 - Minerva Medica - Journals