Rapid Adaptation to Eccentric Exercise-Induced Muscle Damage

Abstract

This study examined eccentric exercise-induced muscle damage and rapid adaptation. Twenty-two male subjects performed 70 eccentric actions with the knee extensors. Group A (n = 11) and group B (n = 11) repeated the same exercise 4 and 13 days after the initial bout, respectively. Criterion measures included muscle soreness, muscle force generation (vertical jump height on a Kistler platform), and plasma levels of creatine kinase (CK), slow-twitch skeletal (cardiac beta-type) myosin heavy chains (MHC), and cardiac troponin I. Subjects were tested pre-exercise and up to day 4 following each bout. The initial exercise resulted in an increase in CK and MHC, a decrement in muscle force, and delayed onset muscle soreness in all participants. CK and MHC release correlated closely (rho = 0.73, p = 0.0001), both did not correlate with the decrement in muscle force generation after exercise. Because cardiac troponin I could not be detected in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for a injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Repetition of the initial eccentric exercise bout after 13 days (group B) did not cause muscle soreness, a decrement in muscle reaction force with vertical jump or significant changes in plasma MHC and CK concentrations, whereas in case of repetition after 4 days (group A) only the significant increases in CK and MHC were abolished. The decrement in reaction force with vertical jump did not differ significantly from that after the initial exercise session, but perceived muscle soreness was less pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

The Relationship Between Isokinetic Quadriceps Strength Test and Hop Tests for Distance and One-Legged Vertical Jump Test Following Anterior Cruciate Ligament Reconstruction

“…Several authors have studied the reliability of the one-legged and twolegged vertical jump (3,5,19,24,33). The findings of Barber et al (3) and Risberg et al (24) did not support the reliability of the one-legged and two-legged vertical jump test.…”

“…In contrast, some authors do s u p port the reliability of the one-legged (19) and two-legged (5,33) vertical jump in healthy subjects when using a contact mattress (5.33) or a Kistler platform (19). Evaluation of twolegged tests also implies measurements of the uninvolved leg that may affect the test result.…”

“…Therefore, we concluded that the one-legged vertical jump is sensitive enough to detect functional limitations of the lower limb following knee ligament reconstruction even greater than 54 weeks after surgery ( (32), a test-retest protocol has to be accurate and consistent. In our opinion, this can only be guaranteed by using a computer-interfaced system (19,32). The sensitivity of the vertical jump decreases, however, when both legs are used.…”

“…Furthermore, the findings of Risberg et al (24) and Barber et al (3) do not support the reliability of the vertical jump. Unfortunately, there are different methods in the literature used to perform the vertical jump (3,8,15,19,24,32), and often the test description is inaccurate.…”

Desmistificando a Ação Do Lactato Nos Eventos De Dor Muscular Tardia Induzida Pelo Exercício Físico: Proposta De Uma Aula Prática

“…Como conseqüência, haveria a caracterização dos seguintes sintomas: DMT [18][19][20], decréscimo na produção de força muscular [1,6], alterações na amplitude de movimento [22,23] e liberação enzimática no meio extracelular [24,25].…”