The effect of sports specialization on musculus quadriceps function after exercise-induced muscle damage

Abstract

The primary aim of the present study was to examine the effect of eccentric exercise-induced (100 submaximal eccentric contractions at an angular velocity of 60° s⁻¹, with 20-s rest intervals) muscle damage on peripheral and central fatigue of quadriceps muscle in well-trained long-distance runners, sprint runners, volleyball players, and untrained subjects. We found that (i) indirect symptoms of exercise-induced muscle damage (prolonged decrease in maximal voluntary contraction, isokinetic concentric torque, and electrically induced (20 Hz) torque) were most evident in untrained subjects, while there were no significant differences in changes of muscle soreness and plasma creatine kinase 48 h after eccentric exercise between athletes and untrained subjects; (ii) low-frequency fatigue was greater in untrained subjects and volleyball players than in sprint runners and long-distance runners; (iii) in all subjects, electrically induced (100 Hz) torque decreased significantly by about 20%, while central activation ratio decreased significantly by about 8% in untrained subjects and sprint runners, and by about 3%-5% in long-distance runners and volleyball players. Thus, trained subjects showed greater resistance to exercise-induced muscle damage for most markers, and long-distance runners had no advantage over sprint runners or volleyball players.

Effects of Oral Branched‐Chain Amino Acids (BCAAs) Intake on Muscular and Central Fatigue During an Incremental Exercise

“…Muscle fatigue is the main limiting factor for physical performance during prolonged exercise and is characterised by impaired excitation-contraction coupling (Marshall et al, 2014;Presland et al, 2005). Several studies have reported on metabolic and neuromuscular factors that cause fatigue during prolonged exercise in athletes (Presland et al, 2005;Skurvydas et al, 2011). However, fatigue can occur in the absence of underlying mechanisms.…”

“…It has been suggested that depletion of muscle glycogen and hypoglycaemia reduce muscle function during long-distance running (Bailey et al, 1993). Fatigue mechanisms may also include muscle metabolite accumulation (Bingham et al, 2017;Skurvydas et al, 2011), production of reactive oxygen species (ROS) (Nielson et al, 2008), and altered motor unit recruitment patterns (Bingham et al, 2017). Additionally, it is well documented that leakage of intracellular enzymes into plasma that are associated with decreased metabolic stability, such as creatine kinase (CK) and myoglobin could affect performance (Koo et al, 2014;Skurvydas et al, 2011).…”

“…Fatigue mechanisms may also include muscle metabolite accumulation (Bingham et al, 2017;Skurvydas et al, 2011), production of reactive oxygen species (ROS) (Nielson et al, 2008), and altered motor unit recruitment patterns (Bingham et al, 2017). Additionally, it is well documented that leakage of intracellular enzymes into plasma that are associated with decreased metabolic stability, such as creatine kinase (CK) and myoglobin could affect performance (Koo et al, 2014;Skurvydas et al, 2011). However, cessation of prolonged exercise occurs not because of muscular fatigue, but due to central fatigue (Eichelberger and Bilodeau, 2007;Skurvydas et al, 2011).…”

“…Additionally, it is well documented that leakage of intracellular enzymes into plasma that are associated with decreased metabolic stability, such as creatine kinase (CK) and myoglobin could affect performance (Koo et al, 2014;Skurvydas et al, 2011). However, cessation of prolonged exercise occurs not because of muscular fatigue, but due to central fatigue (Eichelberger and Bilodeau, 2007;Skurvydas et al, 2011).…”

The Acute Effects Different Quantities of Branched-Chain Amino Acids Have On Recovery of Muscle Function

“…However, it is widely acknowledged that intensive resistance training leads to exercise-induced muscle damage (EIMD) that can last several days [2]. Symptoms of EIMD include decreased muscle function, reduced range of functional movement [3,4], increased muscle soreness and swelling [5], and increased serum intramuscular proteins [6]. Consequently EIMD can have an abstruse effect on the ability to complete successive bouts of physical training, thus directly impacting consistency within a given training programme [7].…”