Increasing the resting time between drop jumps lessens delayed-onset muscle soreness and limits the extent of prolonged low-frequency force depression in human knee extensor muscles

• Published in: European journal of applied physiology Vol. 122; no. 1; pp. 255 - 266
• Main Authors: Kamandulis, Sigitas, Mickevicius, Mantas, Snieckus, Audrius, Streckis, Vytautas, Montiel-Rojas, Diego, Chaillou, Thomas, Westerblad, Hakan, Venckunas, Tomas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2022; Springer Nature B.V
• Subjects: Adult; Biomarkers - blood; Biomedical and Life Sciences; Biomedicine; Biopsy; Biopsy, Needle; Creatine Kinase - blood; Electric Stimulation; Electrical stimulation; Extracellular matrix; Human Physiology; Humans; Kinases; Knee; Knee - physiology; Low-frequency fatigue; Male; Medicin och hälsovetenskap; mRNA; Muscle contraction; Muscle Contraction - physiology; Myalgia - prevention & control; Occupational Medicine/Industrial Medicine; Original Article; Pain Measurement; Physiology; Proteins; Rest; Sarcomere damage; Sports Medicine; Stretch–shortening cycle exercise; Time Factors; Torque; Young Adult; Sarcomere damage; Electrical stimulation; Low-frequency fatigue; Stretch–shortening cycle exercise
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-021-04834-x

Purpose Unaccustomed eccentric contractions generally result in a long-lasting contractile impairment, referred to as prolonged low-frequency force depression (PLFFD), and delayed-onset muscle soreness (DOMS). We here used repeated drop jumps (DJs) as an eccentric contraction model and studied the effects of increasing the time between DJs from 20 s to 5 min. We hypothesized that both PLFFD and DOMS would be less marked at the longer DJ interval due to the longer time to restore structural elements between DJs. Methods Young men ( n  = 12) randomly performed 50 DJs with either 20-s (DJ-20 s) or 5-min (DJ-5 min) rest between DJs. Voluntary, 20 Hz and 100 Hz electrically stimulated isometric knee extension torques and muscle soreness were monitored before and for 7 days after DJs; serum CK activity was measured to assess muscle fibre protein leakage. In additional experiments, changes in mRNA levels were assessed in muscle biopsies collected before and 1 h after exercise. Results A marked PLFFD was observed with both protocols and the extent of 20 Hz torque depression was smaller immediately and 1 day after DJ-5 min than after DJ-20 s ( p  < 0.05), whereas the MVC and 100 Hz torques were similarly decreased with the two protocols. Markedly larger differences between the two protocols were observed for the muscle soreness score, which 1–4 days after exercise was about two times larger with DJ-20 s than with DJ-5 min ( p  < 0.01). Conclusions The larger protective effect of the longer DJ interval against DOMS than against PLFFD indicates that their underlying mechanisms involve different structural elements.