Neuromuscular fatigue following high versus low-intensity eccentric exercise of biceps brachii muscle
Introduction
A succession of eccentric muscular contractions induces systematically a transient reduction in maximal voluntary contraction (MVC) force commonly named muscular fatigue (Friden et al., 1983, Clarkson et al., 1986). For example, there is evidence for a reduction in elbow flexion MVC following eccentric contractions (Hortobàgyi and Katch, 1990, Michaut et al., 2002). This MVC decrease resulted from changes in central and peripheral mechanisms such as decrease of neural input and alterations of the maximal compound action potential (M-wave) and isometric muscular twitch. Warren et al. (1999) suggested that measures of muscle function provide the most effective means of evaluating the magnitude of damage resulting from eccentric muscle actions.
The fatigue level can considerably change according to the characteristics of eccentric exercise, suggesting the concept of “task dependency” (Enoka and Stuart, 1992). There is widespread agreement that damage increases with the length of the stretch (Lieber and Friden, 1993). However, Hunter and Faulkner (1997) observed that the isometric force deficit measured at the original length depends mainly on the work volume applied. Moreover, the results showed that muscular damage would increase with the exercise duration. According to Talbot and Morgan (1996) with repeated eccentric contractions, the number of permanently weakened or overstretched sarcomeres gradually increases. Many studies have found a positive correlation between the degree of damage and the number of eccentric contractions (McCully and Faulkner, 1985, Warren et al., 1993a). For a maximal intensity of exercise, the maximum force reduction seems to be more significant when the number of repetition is high (Nosaka and Sakamoto, 2001, Nosaka and Newton, 2002). Previous studies also showed that the magnitude of force reduction was positively correlated with the level of tension development (Hunter and Faulkner, 1997, Gosselin and Burton, 2002). Warren et al. (1993a) reported that muscular damages are initiated by mechanical factors, where muscular tension constitutes the principal element. Nosaka and Newton (2002) have shown that muscular tissue damage was appreciably lower after three sets of ten submaximal contractions (50% of maximal voluntary contraction) than three sets of ten maximal contractions (100% of maximal voluntary contraction).
A reduced efficiency of excitation–contraction (E–C) coupling process has been demonstrated after eccentric exercise in humans through the use of the muscular tension developed and activation relationship (Jones, 1996). Furthermore, these investigators estimated that at least 75% of the reduction in the maximal force evoked by a tetanic stimulation was due to E–C coupling failure immediately post-exercise, and although the contribution declined with recovery, they estimated that E-C coupling failure accounted for at least 57% of the reduction in titanic force at 5 days post-exercise (Edwards et al., 1977, Jones, 1981). Consequently, failure of E–C coupling will impair maximal and submaximal force generation. Paschalis et al. (2005) indicated that matching volumes of maximal intensity (100% of peak torque) and submaximal intensity (50% of peak torque) eccentric exercise have similar effects on muscle damage, but maximal intensity has a more prominent effect on muscle performance. This difference in peak torque reduction could be explained by a more significant central fatigue for the maximal intensity compared to the submaximal intensity. Previous studies have shown that eccentric muscle actions of the biceps brachii induced a decrease in neural input during MVC evidenced by a reduction in maximal myoelectrical activity of this muscle or a decrease in maximal voluntary activation (Gibala et al., 1995, Michaut et al., 2002). To our knowledge, Paschalis et al. (2005) investigation is the only study that examined the difference in muscle damage and muscle performance perturbations in relation to maximal and submaximal intensity eccentric exercise corresponding to the same amount of work. However, this study has not investigated the components of neuromuscular fatigue. Therefore, the purpose of the present study was to examine the effects of high versus low-intensity eccentric exercise on peripheral and central component of muscular fatigue. According to Paschalis et al. (2005) results, we hypothesised that a high-intensity eccentric exercise may induce greater MVC decrease and central fatigue than low-intensity eccentric exercise, corresponding to the same amount of work. To test this hypothesis, neural and contractile properties of the biceps brachii muscles were examined before, immediately after and 48 h after a series of eccentric contractions performed at two different intensities (high versus low).
Section snippets
Approach to the problem and experimental design
This experiment was conducted to examine the effect of the intensity of eccentric exercise of the biceps brachii muscle on neuromuscular function. To examine central and peripheral components of fatigue, transcutaneous stimulation of the musculo-cutaneous nerve was performed to evaluate maximal voluntary activation level (VA), muscular twitch and M-wave of the biceps brachii muscle.
Subjects
Ten right handed healthy untrained volunteers (6 males and 4 females) (mean ± SD: age 27.3 ± 3.9 y; weight 68.2 ± 8.3 kg;
Muscular strength
MVC torque was significantly reduced post-exercise (P < 0.01) by 20% after the HI exercise and by 25% after the LI exercise with no difference between the two sessions (Fig. 2). MVC values after 48 h remained significantly lower than the Pre value for both HI and LI exercise (HI: 78.6 ± 6.4% of Pre; LI: 72.8 ± 5.9% of Pre, P < 0.001), with no difference between the two conditions.
Evoked twitch
Table 1 displays the main changes in the evoked mechanical response of the twitch. Pt decreased at Post for LI exercise by 56 ±
Discussion
The main findings of the present study were: (i) a similar MVC torque reduction associated with a reduced maximal EMG of the biceps brachii muscle immediately after exercise and after 48 h for HI and LI exercise, (ii) a significant reduction of maximal voluntary activation immediately after the HI exercise only, (iii) similar alterations of excitation contraction coupling process after the exercise for both HI and LI exercise.
The present results show that the 20% MVC torque decrease for HI and
Conclusion
HI and LI eccentric exercises, corresponding to the same amount of work, induced the same reduction of maximal strength capacity of the biceps brachii. For both exercises, the MVC reduction was due to central and peripheral alterations. Present data suggests that muscle fatigue following eccentric exercise of the biceps brachii muscle is independent of the intensity of the contraction when total work performed is the same.
Elodie Gauché received his Ph.D. from the University of Paris 5, France (Laboratory of Biomechanics and Physiology, French National Institute of Sports) in december 2007. His research interests focus on neuromuscular alterations following eccentric exercise and the effects of antioxidants supplementation on neuromuscular recovery and oxidative stress. She is a consultant-journalist for a football TV channel.
References (33)
- et al.
Tonic vibration reflexes elicited during fatigue from maximal voluntary contractions in man
J. Physiol.
(1990) Alteration in sarcoplasmic reticulum: a possible link to exercise induced muscle damage
Med. Sci. Sports Exerc.
(1992)- et al.
Neuromuscular function after exercise-induced muscle damage: theoretical and applied implications
Sports Med.
(2004) - et al.
Exercise-induced muscle damage in humans
Am. J. Phys. Med. Rehabil.
(2002) - et al.
Muscle soreness and serum creatine kinase activity following isometric, eccentric, and concentric exercise
Int. J. Sports Med.
(1986) Central and peripheral factors in fatigue
J. Sports Sci.
(1995)- et al.
Fatigue of long duration in human skeletal muscle after exercise
J. Physiol.
(1977) - et al.
Neurobiology of muscle fatigue
J. Appl. Physiol.
(1992) - et al.
Myofibrillar damage following intense eccentric exercise in man
Int. J. Sports Med.
(1983) Spinal and supraspinal factors in human muscle fatigue
Physiol. Rev.
(2001)
Role of muscle afferents in the inhibition of motoneurons during fatigue
Adv Exp Med Biol
Reflex inhibition of human soleus muscle during fatigue
J. Physiol.
Changes in human skeletal muscle ultrastructure and force production after acute resistance exercise
J. Appl. Physiol.
Impact of initial muscle length on force deficit following lengthening contractions in mammalian skeletal muscle
Muscle Nerve
Eccentric and concentric torque velocity relationships during arm flexion and extension
Eur. J. Appl. Physiol.
Pliometric contraction-induced injury of mouse skeletal muscle: effect of initial length
J. Appl. Physiol.
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Elodie Gauché received his Ph.D. from the University of Paris 5, France (Laboratory of Biomechanics and Physiology, French National Institute of Sports) in december 2007. His research interests focus on neuromuscular alterations following eccentric exercise and the effects of antioxidants supplementation on neuromuscular recovery and oxidative stress. She is a consultant-journalist for a football TV channel.
Antoine Couturier received his Ph.D. in Biomedical Engineering from the University of Lyon I, France in June 1999. He is a research engineer at the National Institute for Sports (INSEP), Paris, France. His work essentially focuses on signal processing, software development and electronics.
Romuald Lepers is Assistant Professor in the National Institute of Health and Medical Research at the University of Dijon in Burgundy, France. His research interests focus on the mechanisms of human fatigue during prolonged exercises such as cycling and running, and the neuromuscular adaptations to sustained submaximal contractions
Anne Michaut received his Ph.D. in the National Institute of Health and Medical Research at the University of Dijon in Burgundy, France in November 2000. His research interests focus on recovery of muscular contractility after a strength training session. She is the physical trainer of the French National Archery Team.
Giuseppe Rabita received his Ph.D. from the University of Lille 2, France (Laboratory of Human Motricity, LEMH) in December 2001. He studied muscle mechanics and neurophysiological adaptations (strength training, motor disorders). He is currently researcher at the French National Institute of Sports (INSEP), Paris, France. He joined the Laboratory of Biomechanics and Physiology to study the adaptations in musculotendinous mechanical properties and their influence on the global musculoskeletal stiffness and the performance during stretch-shortening cycle exercises.
Christophe Hausswirth is researcher and Assistant Professor at the national Institute for Sports and physical éducation in Paris, France. His research interests focus on the mechanisms underlying performance especially in elite athletes and triathletes.