Adaptations of Muscle Tissue of Rats Submitted to Aerobic and Anaerobic Physical Training in Different Ergometer Models

Abstract

The objective of the present study was to analyze the effects of four different training models, two aerobic and two anaerobic models, in relation to muscular hypertrophy, by means of morphometric analysis of the muscle cells of the soleus muscle and the extensor digitorum longus muscle (EDL). The animals were divided into five groups, control (C), aerobic training in swimming (ATS), resistance training in water (RTW), aerobic training on a treadmill (ATT), and resistance training in climbing (RTC). The aerobic training was performed at 70 % of the anaerobic threshold for 30 minutes, while the RTW was composed of 3 series of 10 jumps, and the RTC 4 series of climbs, both at 80 % of the maximum load. All training protocols were performed for a total period of 4 weeks, 3 times per week. The diameters of the muscle cells were measured by means of histological slides of the EDL and soleus muscles. For the EDL muscle, there was no difference between the ATS and ATT aerobic training models (p = 0.20). However, the RTW presented greater hypertrophy when compared to the RTC (p <0.01). Regarding the soleus muscle, the ATS was responsible for generating greater hypertrophy than the ATT (p <0.01). In addition, the RTC was more efficient at producing hypertrophy than the RTW (p <0.01). In this way, it was concluded that exercise adaptation was according to exercise type, aerobic or anaerobic, and not to the modality used.

Effect of Aerobic and Anaerobic Training on Different Ergometers in Rat Muscle and Heart Tissues

“…5,7,18,19 The greater the intensity of the exercise, the greater the stimulus for hypertrophy, promoting greater stimulus to the protein synthesis of the contractile elements responsible for muscle contraction, generating an increase in the volume of muscle fiber. 5,6,17 The muscle hypertrophy process is modulated by the mechanical stimulus to which the muscle tissue is submitted, so an exercise with greater overload will promote greater stimulus for muscle hypertrophy. 20 In addition, a study carried out with exercise on a stationary exercise bike 21 that the stimulus for the hypertrophy pathway, and increase in the glucose transporter (GLUT4), occurred with greater magnitude in type II muscle fibers, than in type I muscle fibers, a fact that could explain the hypertrophy observed only in type II fibers in the current study.…”

“…18 Aerobic exercise is best known for promoting improvement in oxidative capacity, increased blood perfusion, and the number of mitochondria, generating greater resistance to fatigue. 3,6 A review study looked at the effectiveness of aerobic training for gaining muscle hypertrophy, and found that there is hypertrophy when the exercise is performed over the long term (9 to 12 weeks). 22 In the current study, only 4 weeks of training were performed, so the training time may have been decisive for the non-adaptation of the slow-twitch muscles to exercise.…”

“…The second group includes exercises with high intensity and lower volume. 3,5,6 Anaerobic training presents greater stimulus for muscle hypertrophy, since it can promote synthesis of contractile elements, which consequently increases the contraction force. 3,5,6 Aerobic training presents greater stimulus for resistance to fatigue, with greater oxidative capacity, an increased number of mitochondria, and improved blood perfusion.…”

“…3,5,6 Anaerobic training presents greater stimulus for muscle hypertrophy, since it can promote synthesis of contractile elements, which consequently increases the contraction force. 3,5,6 Aerobic training presents greater stimulus for resistance to fatigue, with greater oxidative capacity, an increased number of mitochondria, and improved blood perfusion. 6,7 In cardiac muscle tissue, aerobic training is known to promote physiological hypertrophy and improve parameters such as ejection volume and reduced peripheral resistance.…”

“…3,5,6 Aerobic training presents greater stimulus for resistance to fatigue, with greater oxidative capacity, an increased number of mitochondria, and improved blood perfusion. 6,7 In cardiac muscle tissue, aerobic training is known to promote physiological hypertrophy and improve parameters such as ejection volume and reduced peripheral resistance. Anaerobic training is seen as a valuable tool to promote adaptations in the cardiovascular system, such as hypertrophy of cardiomyocytes and increased thickness of the left ventricle.…”