Abstract
Background: This study aimed to compare the muscle activity between the symmetric and selected asymmetric loads (2.5%; 5% and 7.5% differences in load position between sides of the bar) during the flat bench press (BP) exercise at 70%1RM. The study included 10 resistance-trained males (25.3 ± 2.3 years; 82.9 ± 6.9 kg; 177.8 ± 4.5 cm; 1RM BP: 104.5 ± 8.6 kg; experience: 5.6 ± 1.5 years). Methods: To assess the differences in muscle activity between both sides of the body and load placement, the participants performed several attempts of the BP with symmetric and asymmetric load at 70%1RM in a random order (symmetric; 2.5%; 5% and 7.5% differences in load position between sides of the bar). Peak muscle activity of dominant and non-dominant body-side was recorded for the pectoralis major (PM), anterior deltoid (AD), and the long head of the triceps brachii (TB). Results: A two-way repeated-measures analysis of variance (ANOVA) indicated a statistically significant main interaction between side and load (p < 0.01) for AD, PM and TB muscles. Conclusion: The results of this study showed that asymmetrically loaded BP leads to significantly higher muscle activity on the loaded side of the body. The offset training method during bilateral resistance exercise may be an effective and simple approach for reductions in muscle imbalances and improvement in bilateral exercise performance.
Highlights
In competitive sports, inter-limb asymmetry is often observed due to repetitive overuse of the active and passive movement apparatus [1]
A statistically significant higher muscle activity for the left side was found at 2.5%, 5% and 7.5% left asymmetric loading compared to right side (Figure 1)
Most studies focused on instability in resistance training modes, such as free weights instead of a machines [27], dumbbells instead of barbells [19,28], unilateral instead of bilateral exercises [29,30], and the results indicate that those methods effectively increase muscle activity of the prime movers during the performance of particular resistance exercises, even with lower external loading when compared to traditional approaches
Summary
Inter-limb asymmetry is often observed due to repetitive overuse of the active and passive movement apparatus [1]. Demands of particular sport-specific movements place greater stress on one side of the body, increasing the disproportions between them [2]. Many studies have been conducted to quantify and reduce inter-limb asymmetries due to training intervention [2,5,6], the offset training method still has not been explored. The offset training method relies on performing resistance exercises with an asymmetrical position of the external load. Contrary to unilateral exercises with contralateral or ipsilateral external load placement, the offset training method assumes bilateral but asymmetrical position of the external load. The higher external load placed on one side of the body, the greater the postural control as well as the lateral and rotational stability demands on the athlete. The study included 10 resistance-trained males (25.3 ± 2.3 years; 82.9 ± 6.9 kg; 177.8 ± 4.5 cm; 1RM BP: 104.5 ± 8.6 kg; experience: 5.6 ± 1.5 years)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
