Document Type: Original Articles

Authors

1 Department of Physical Education, Mahallat Branch, Islamic Azad University, Mahallat, Iran

2 Center for Biomechanic and Motor Control, Department of Sport Science, University of Bojnord, Bojnord, Iran

Abstract

 Manipulating resistance training program variables is a commonly used tool for optimizing maximum muscle strength in rehabilitation and/or exercise training programs. The current study purposed to compare the effects of 12 weeks of concentric and eccentric resistance training on neuromuscular adaptation of quadriceps muscle.
Methods
 Twenty-six male subjects (age, mean ± SD, 22.1 ± 2.4 yr; body mass, 72.3 ± 9.9 kg; height, 1.75 ± 0.08 m) were recruited for this controlled laboratory study. Subjects were randomly divided into two groups: the eccentric training group (No = 13) and the concentric training group (No = 13). The maximal isometric voluntary contraction (MVIC) of quadriceps muscles, vertical jumping, and surface electromyography (EMG) signals were recorded before and after 12 weeks of resistance concentric and eccentric training. Repeated-measures Analysis of Variance (ANOVA) was used to test differences between means before and after resistance training.
Results
 The maximal isometric voluntary contraction of the quadriceps muscle and vertical jumping were significantly increased after eccentric and concentric training (p <0.05). Eccentric exercise resulted in a greater increase in maximal isometric voluntary contraction of the quadriceps muscle and vertical jumping compared to concentric training (p <0.05). The amplitude of surface EMG signals was also significantly increased after eccentric and concentric training (p <0.05), with a greater increase observed in the eccentric than the concentric training group (p <0.05).
Conclusion
 The results of this study showed higher increases in muscle force output and EMG activity after eccentric training. This may indicate that stretch combined with overloading is the most effective stimulus for enhancing neuromuscular activity during dynamic resistance exercise. The knowledge gained from this study may be relevant for designing exercise and/or rehabilitation training to improve muscle output.

Keywords

 

1)       Hedayatpour N, Falla D.  Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training. Biomed Res Int. 2015; 2015:193741.

2)      Gandevia SC. Spinal and supraspinal factors in human muscle fatigue. Physiol Rev. 2001;81(4):1725-89

3)      Abdi N, Hamedinia MR, Izanloo Z, Hedayatpour N. The effect of linear and daily undulating periodized resistance training on the neuromuscular function and the maximal quadriceps strength BJHPA. 2019; 11 (1): 45-53.

4)       Mazani AA, Hamedinia MR, Haghighi AH, Hedayatpour N. The effect of high speed strength training with heavy and low workloads on neuromuscular function and maximal concentric quadriceps strength. J Sports Med Phys Fitness. 2018; 58 (4):428-434.

5)       Moritani T and DeVries H. A.  Neural factors versus hypertrophy in the time course of muscle strength gain. The American Journal of Physical Medicine 1979; 58: 115–130.

6)       Farthing  J. P. and Chilibeck P. D. The effects of eccentric and concentric training at different velocities on muscle hypertrophy,” Eur J Appl Physiol. 2003; 89: 578–586.

7)       Hedayatpour N, Falla D. Non-uniform muscle adaptations to eccentric exercise and the implications for training and sport. J Electromyogr Kinesiol. 2012; 22(3):329-333.

8)       Hedayatpour N, Falla D, Arendt-Nielsen L, Vila-Chã C, Farina D. Motor unit conduction velocity during sustained contraction after eccentric exercise. Med Sci Sports Exerc. 2009; 41(10):1927-1933.

9)       Hedayatpour N, Falla D, Arendt-Nielsen L, Farina D. Effect of delayed-onset muscle soreness on muscle recovery after a fatiguing isometric contraction. Scand J Med Sci Sports. 2010; 20(1):145-153.

10)   Nasrabadi R, Izanloo Z, Sharifnezad A, Hamedinia MR, Hedayatpour N. Muscle fiber conduction velocity of the vastus medilais and lateralis muscle after eccentric exercise induced-muscle damage. J Electromyogr Kinesiol. 2018; 43:118-126.

11)   Altenburg TM, de Ruiter CJ, Verdijk PW, van Mechelen W, de Haan A. Vastus lateralis surface and single motor unit electromyography during shortening, lengthening and isometric contractions corrected for mode-dependent differences in force-generating capacity. Acta Physiologica. 2009;196: 315–328.

12)   Hedayatpour N, Arendt-Nielsen L, Farina D. Motor unit conduction velocity during sustained contraction of the vastus medialis muscle. Exp Brain Res. 2007; 180(3):509-516.

13)  Hortobágyi T, Houmard J, Fraser D, Dudek R, Lambert J, Tracy J. Normal forces and myofibrillar disruption after repeated eccentric exercise. J Appl Physiol 1998; 84: 492-8.

14)   Hedayatpour N, Falla D, Arendt-Nielsen L, Farina D. Sensory and electromyographic mapping during delayed-onset muscle soreness. Med Sci Sports Exerc. 2008; 40(2):326-334.

15)   Roig M, O'Brien K, Kirk G, et al. The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis. Br J Sports Med. 2009; 43(8):556-568.

16)   Toumi H, Best TM, Martin A, F'Guyer S, Poumarat G. Effects of eccentric phase velocity of plyometric training on the vertical jump. Int J Sports Med. 2004; 25(5):391-398.

17)   Miller JD, Sterczala AJ, Trevino MA, Wray ME, Dimmick HL, Herda TJ. Motor unit action potential amplitudes and firing rates during repetitive muscle actions of the first dorsal interosseous in children and adults. Eur J Appl Physiol. 2019; 119(4):1007-1018.

18)  Hedayatpour N, Arendt-Nielsen L, Farina D. Non-uniform electromyographic activity during fatigue and recovery of the vastus medialis and lateralis muscles. J Electromyogr Kinesiol. 2008; 18(3):390-396.

19)   Kamen G, Knight CA. Training-related adaptations in motor unit discharge rate in young and older adults. J Gerontol A Biol Sci Med Sci. 2004; 59(12):1334-1338.

20)   Vila-Chã C, Falla D, Farina D. Motor unit behavior during submaximal contractions following six weeks of either endurance or strength training. J Appl Physiol. 2010; 109 (5):1455-1466.

21)   Dartnall TJ, Rogasch NC, Nordstrom MA, Semmler JG. Eccentric muscle damage has variable effects on motor unit recruitment thresholds and discharge patterns in elbow flexor muscles. J Neurophysiol. 2009; 102(1):413-423.

22)   Romanò C, Schieppati M. Reflex excitability of human soleus motoneurones during voluntary shortening or lengthening contractions. J Physiol. 1987; 390:271-284.

23)   Fang Y, Siemionow V, Sahgal V, Xiong F, Yue GH. Greater movement-related cortical potential during human eccentric versus concentric muscle contractions. J Neurophysiol. 2001; 86(4):1764-1772.

24)   Yue GH, Liu JZ, Siemionow V, Ranganathan VK, Ng TC, Sahgal V. Brain activation during human finger extension and flexion movements. Brain Res. 2000; 856(1-2):291-300.

25)   Matthews PB. The human stretch reflex and the motor cortex. Trends Neurosci. 1991; 14(3):87-91.

 

26)   Babault N, Pousson M, Ballay Y, Van Hoecke J. Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. J Appl Physiol.  2001; 91(6):2628-34.