Unilateral arm strength training improves contralateral peak force and rate of force development

Abstract

Neural adaptation following maximal strength training improves the ability to rapidly develop force. Unilateral strength training also leads to contralateral strength improvement, due to cross-over effects. However, adaptations in the rate of force development and peak force in the contralateral untrained arm after one-arm training have not been determined. Therefore, we aimed to detect contralateral effects of unilateral maximal strength training on rate of force development and peak force. Ten adult females enrolled in a 2-month strength training program focusing of maximal mobilization of force against near-maximal load in one arm, by attempting to move the given load as fast as possible. The other arm remained untrained. The training program did not induce any observable hypertrophy of any arms, as measured by anthropometry. Nevertheless, rate of force development improved in the trained arm during contractions against both submaximal and maximal loads by 40-60%. The untrained arm also improved rate of force development by the same magnitude. Peak force only improved during a maximal isometric contraction by 37% in the trained arm and 35% in the untrained arm. One repetition maximum improved by 79% in the trained arm and 9% in the untrained arm. Therefore, one-arm maximal strength training focusing on maximal mobilization of force increased rapid force development and one repetition maximal strength in the contralateral untrained arm. This suggests an increased central drive that also crosses over to the contralateral side.

Bilateral Effect of Unilateral Isokinetic Concentric Training and Russian Current Stimulation on Quadriceps Strength

“…The results of effective programs are usually observed as increased one repetition maximum (1RM) or improved ability to develop force and power. While muscle hypertrophy is associated with increased cross-section of the myocyte and whole-muscle 6,7 , neural adaptation is not 8 .…”

Time to task failure of the contralateral untrained limb after high load-low repetition eccentric and low load-high repetition resistance training

“…Numerous studies have investigated cross training following strength training. For example, Adamson et al 10 reported that unilateral arm strength training improves contralateral peak force and rate of force development .Accordingly, cross-training effect has been observed in different muscles groups after different mode of exercise training and at different levels of task complexity 9,11 . It has been reported that crosstraining process is primarily caused by adaptations in the central nervous system CNS) for the untrained limb following exercise training 12,13,14 .…”

Efeito do exercício excêntrico sobre as propriedades mecânicas do músculo e índices de aptidão aeróbia

“…Com isso, o tempo reduzido de contração durante movimentos rápidos do membro, pode não permitir que se atinja a força máxima muscular. Neste caso, a melhor análise a ser realizada é a determinação do aumento da força, a partir do início da contração, através da TDF ADAMSON et al, 2008;THORLUND et al, 2008), TDT (CONNELLY;VANDERVOORT, 2000) e taxa de desenvolvimento de velocidade (TDV) (BROWN; WHITEHURST, 2003;FINDLEY et al, 2006;MILLER et al, 2006). Figura 1.4.…”

“…Com o mesmo propósito, a taxa de aumento de força em contrações dinâmicas tem sido analisada no joelho (THORLUND et al, 2008), tornozelo (CONNELLY; VANDERVOORT et al, 2000) e ombro (ADAMSON et al, 2008). O pico TDT é observado próximo de 90ms em extensão do joelho sem carga (ANDERSEN et al, 2005), sendo que a melhor correlação entre a taxa isométrica e dinâmica de aumento da força ocorre neste momento (THORLUND et al, 2008).…”

“…Além disso, o curto tempo de contração, durante movimentos rápidos do membro, pode não ser suficiente para se atingir a força muscular máxima. Neste caso, a melhor análise a ser realizada é a determinação do aumento da força, a partir do início da contração, que pode ser obtida através da taxa de desenvolvimento de força (TDF) ADAMSON et al, 2008;THORLUND;, taxa de desenvolvimento de torque (TDT) (CONNELLY; VANDERVOORT, 2000) e taxa de desenvolvimento de velocidade (TDV) (BROWN; WHITEHURST, 2003;FINDLEY et al, 2006;MILLER et al, 2006). Enquanto a TDF tem sido avaliada em contrações isométricas (AAGAARD et al, obtidas durante contrações dinâmicas (BROWN; WHITEHURST, 2003;CONNELLY;VANDERVOORT, 2000, FINDLEY et al, 2006MILLER et al, 2006).…”