نوع مقاله : علمی - پژوهشی
نویسندگان
1 گروه فیزیولوژی ورزشی، دانشکده تربیت بدنی و علوم ورزشی، دانشگاه خوارزمی، تهران، ایران
2 دکتری تخصصی بیومکانیک ورزش، گروه بیومکانیک و آسیب شناسی ورزش، دانشکده تربیت بدنی و علوم ورزشی، دانشگاه خوارزمی، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Introduction and Aim: Beta-alanine (BA) supplementation is an effective factor in enhancing sports performance and delaying fatigue, particularly during lactate-based training or sports. However, its effects when combined with resistance training at different intensities on neuromuscular adaptation have not been well clarified. Therefore, the purpose of this study was to determine the effects of eight weeks of high- and low-intensity resistance training performed to failure, combined with beta-alanine supplementation, on electromyographic (EMG) activity and performance-related factors of the biceps brachii muscle in trained young adults.
Methods: Sixteen resistance-trained young men (age: 23.0 ± 2.0 years; body mass index: 25.81 ± 4.89 kg/m²) were assigned to either a resistance training plus beta-alanine supplementation group or a resistance training plus placebo group. Participants completed an eight-week resistance training program (24 sessions) using a unilateral, symmetrical limb design with two training intensities (high and low). In both groups (supplement and placebo), one arm performed high-intensity resistance training (75–80% of one-repetition maximum), while the contralateral arm performed low-intensity resistance training (60–65% of one-repetition maximum), with all sets performed to failure in each set. Performance variables included training volume, strength, power, muscular endurance, and the maximal relative range of electromyographic activity of the biceps brachii muscle. These variables were assessed before and after the training period and analyzed using paired-sample t tests and analysis of covariance with SPSS software (version 27).
Results: Beta-alanine supplementation with resistance training resulted in significant improvements in training volume (P = 0.001), muscular strength (P = 0.001), power (P = 0.037), and muscular endurance (P = 0.013) compared with resistance training combined with placebo. However, changes in EMG-based neuromuscular indices did not show significant differences between groups (P = 0.928). Additionally, low-intensity resistance training resulted in significantly greater increases in training volume compared with high-intensity training (P = 0.001), whereas no significant differences were observed between high- and low-intensity training for EMG variables (P = 0.822), muscular strength (P = 0.553), power (P = 0.603), or muscular endurance (P = 0.232).
Discussion and Conclusion: Beta-alanine supplementation combined with resistance training may be an effective strategy for improving muscular strength, power, and endurance, although it did not demonstrate a significant effect on neuromuscular adaptation. In addition, beta-alanine supplementation during lower-intensity resistance training may allow a greater number of repetitions and higher training volume; however, it does not result in superior functional adaptations compared with higher-intensity training. Considering the importance of training volume in structural adaptations, the effectiveness of beta-alanine–induced increases in training volume should be investigated over longer training periods.
Keywords: Resistance Training, Muscle Fatigue, Electromyography, Muscle Strength, βeta-Alanine.
کلیدواژهها [English]
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