Figure - available from: Scandinavian Journal of Medicine and Science in Sports
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The adjusted (covaried for baseline) changes for muscle thickness. Changes at the 60% site in the non‐dominant (A) and dominant (B) arm. Changes at the 70% site in the non‐dominant (C) and dominant (D) arm. The mean changes in muscle thickness are represented by the middle bar, and the upper and lower bars represent the 95% credible intervals. The hypotheses at the top of each figure represent the hypothesis with the greatest posterior probability. D + ND, Training on both dominant and non‐dominant arm; D‐Only, Training on dominant arm only; ND‐Only, Training on non‐dominant arm only; Control, Time‐matched non‐exercise control.
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Training one limb with a high‐load has been shown to augment strength changes in the opposite limb training with a low‐load (via cross‐education of strength), indicating that within‐subject models can be problematic when investigating strength changes. This study examined if the cross‐education of strength from unilateral high‐load training could a...
Citations
... However, the effects of cross-additional strength be gained in that limb if the contralateral limb also undergoes RT? Research suggests that high-load exercise training provides little additive gain in maximal strength (1RM) of the contralateral limb when it undergoes low-load training (5). Furthermore, preliminary results suggest that this additive effect is absent when both limbs undergo RT with similar loads (41). Given that both 1S and 3S conditions in this study used similar external loads, and evidence from other studies using betweensubject design shows that training volume has little influence on upper-limb strength gains (7,33,35,38,42), the potential volume effect on contralateral untrained limb strength gains might theoretically be lower or potentially absent for the contralateral trained limb. ...
Perceived lack of time is a commonly cited reason for not engaging in resistance training (RT). Consequently, there is interest in identifying time-efficient and minimum-effective RT doses. Although RT and rehabilitation programs typically aim for muscle-specific growth, research on the pectoralis major is notably limited despite it being a frequently targeted muscle group. Here we compare the effects of 2 RT volumes on regional pectoralis major hypertrophy and shoulder horizontal abduction strength using a within-subject design. After a non-training control period, 15 untrained young men (age: 24.1 6 3.1 years) participated in a 12-week RT program, comprised of the pec deck exercise, performed in 1 set (1S) vs. 3 sets (3S), in a linear periodization of 20 to 8 repetitions maximum to failure. B-mode ultrasound imaging was used to analyze muscle thicknesses of the pectoralis major clavicular and sternocostal portions, and maximal strength was determined by 1-repetition maximum tests on the pec deck exercise. After 12 weeks of RT, similar increases were observed between conditions for the pectoralis major clavicular (1S = 17%; 3S = 18%) and sternocostal (1S = 21%; 3S = 21%) thicknesses, and maximum strength (1S = 46%; 3S = 43%). Our results indicate no effect of RT volume (1S vs. 3S) on changes in muscle size and strength and do not support regional hypertrophy after pec deck exercise in untrained men. These results have important implications for RT prescription and rehabilitation practices for individuals who may have limited time or those undergoing brief rehabilitation sessions targeting the pectoralis musculature.
... Further investigations are warranted exploring these aspects as well as the neuroplasticity of the strength adaptation (Škarabot et al. 2021). Of additional note, any potential cross-education interference effect on maximum strength (i.e., improvements in the contralateral, traditionally nontrained, and arm) appears negligible in this context, as it is unlikely to occur when both limbs are trained, particularly with similar loads (Song et al. 2024). ...
In the present study, the effects of resistance training on regional hypertrophy and maximum strength of the elbow flexor muscles were compared between elbow flexion exercises performed with different shoulder joint angles (∼50° of flexion vs. extension) while matched for resistance profiles. In a within‐subject design, 15 young men (25.6 ± 2.1 y; 77.3 ± 6.8 kg; 175.1 ± 5.7 cm) underwent a resistance training program twice a week for 10 weeks (3–5 sets, 8–12RM), and their arms were dominant‐side balanced, randomly assigned to one of the two conditions according to elbow flexion exercises: unilateral cable curl with shoulder flexed (Preacher curl; PREA) or unilateral cable curl with shoulder extended (Bayesian curl; BAYE). B‐mode ultrasound imaging was used to measure changes in muscle thickness of the biceps brachii and brachialis at proximal, mid, and distal arm regions, and one‐repetition maximum tests were completed in each respective trained exercise before and after training. Both conditions showed significant increases in muscle thickness (p < 0.05) with no significant differences between them (p > 0.05) across the biceps brachii proximal, mid, and distal regions (relative change [Hedges' g effect size]; PREA: 6%[0.51], 7%[0.49], 7%[0.53]; BAYE: 9%[0.73], 9%[0.62], 9%[0.62]) and brachialis (PREA: 10%[0.72]; BAYE: 8%[0.65]). Similarly, significant improvements in maximum strength were observed (p < 0.05), with equivalent results between conditions (PREA: 28%[0.85], BAYE: 37%[1.22]; equivalence testing, p‐values = 0.061, 0.637). In conclusion, the shoulder joint angle does not seem to affect muscle hypertrophy and maximum strength gains after different elbow flexion exercises matched for resistance profiles.
