Introduction of Muscle fatigue

The short-term sprints and interspersed reproduce performance for subsequent sprints are important factors for fitness. The repeated sprint ability (RSA) and repeated-sprint exercise (RSE) have potential manifestation for neural mechanism. The repeated sprint ability (RSA) and time motion analysis defies the muscle activity in the team sports (Bogdanis, 2012). Fatigue in the muscle is the reduction of maximal power output and speed during the exercise. Fatigue mostly develops after the first sprint, and there are the number of reasons and factors for instance generation of motor command for the motor cortex, neural factors, accumulation of metabolites, muscle fibers, and inadequate motor command in the muscles (Bishop, 2012; Girard, Mendez-Villanueva, & Bishop, 2011).

Peripheral fatigue can be defined as a reduction in the capability of doing muscle exercise. The fatigue transpiring during the exercise s the lack of ability to regain the initial force and power output. It can be referred to the motor units and the process was linked to the cellular and the mechanical changes in the muscular system (Wan, Qin, Wang, Sun, & Liu, 2017). In case of increase in muscle fatigue, the maximum velocity and force decrease significantly, and the force of relaxation is changed. The contraction of the muscle at the maximum capacity results in the reversible decline of force production (Selmi, Haj, Haj, Moalla, & Elloumi, 2016).

Objective of Muscle fatigue

The aim of the present work is to examine the mechanism of physical inactivity and activity for the modification of the muscle fatigue. The variation in the condition of acute and chronic increase is due to physical activity and results as structural, hormonal, metabolic, neural, and molecular adaptation. The fatigue profile is measured for muscle during the fiber composition, high energy metabolic storage, neuromuscular characteristic, capillarization, and transformation of muscles during high intensity activities (Girard, Mendez-Villanueva, & Bishop, 2011). The aim of the present work is to find the peripheral muscle fatigue with the roles of myosin ATPase, pH and Pi for the repeated sprint performance. The difference in the working process is determined for the muscles at rest and maximal exercise. At the muscle level, the limitation of the energy supply is observed for the oxidative metabolism, phosphocreatine hydrolysis, anaerobic glycolysis, and intramuscular accumulation of the hydrogen ions (Wan, Qin, Wang, Sun, & Liu, 2017).

Methods of Muscle fatigue

The hydrolysis of Myosin ATPase enzymes requires the presence of the protein family to complete the process and reaction of orthophosphate and ADP. The reaction requires a complete source of energy for the operation and contraction of muscles (Girard, Mendez-Villanueva, & Bishop, 2011). PH is the potential of hydrogen that is decimal logarithm for the reciprocal of the hydrogen ion activity while on the other hand, Pi is the phosphate ion that is the empirical formula of  and has a molar mass of . In the case of repeated sprint performance, the change in Pi and pH values are observed (Selmi, Haj, Haj, Moalla, & Elloumi, 2016). The higher change is observed due to intense physical exercise that is followed by an acute decrease in the buffer capacity of muscles. The ionic charge is higher and consequently, the increase in non-mitochondrial adenosine triphosphate (ATP) turnover is observed (Selmi, Haj, Haj, Moalla, & Elloumi, 2016). As a result, accumulation of Hydrogen ion becomes higher in the muscle fibers. The higher accumulation of Hydrogen ions is responsible for the abnormal oxidative phosphorylation, ion regulation, and enzyme activity. The cycling exercise causes maximum power output was used in present research for the investigation of the repeated sprint test (Wan, Qin, Wang, Sun, & Liu, 2017). In the present work, repeated sprints are measured for the muscle fatigue. The safe assumption in the present is considered to collect specified data. In order to perform the test for the evaluation of repeated sprints and muscle fatigue, eight participants were considered under examination (Selmi, Haj, Haj, Moalla, & Elloumi, 2016). The instrument used in the present research was Wingate testing Bike Ergometer. Monark 894E is easy to operate and it was used to determine anaerobic demands and to evaluate the peak power. The reliable feature of Monark 894E is to hold for the anaerobic demands related to the self-regulating basket weight breaking system. The appropriate calibration is required to acquire prime results (Wan, Qin, Wang, Sun, & Liu, 2017). In the present situation release and restore the power of the basket is used in the analysis.

All the eight participants performed the test successively for five times. The test continued for 30 seconds and change in blood levels measured the lactate levels.

Lactate analyzer was used for testing of lactic acid, the use of lactate analyzer is to measure the lactate levels in the participants. Lactate is a substance that is produced in the cells of the body and turns the food into energy in case of higher use of muscles of participants (Wan, Qin, Wang, Sun, & Liu, 2017). Cell metabolism depends on the value of pH present in the body in the form of lactic acid. Some of the participants showed that neutral pH values were present in their blood in the form of lactate (Wan, Qin, Wang, Sun, & Liu, 2017).

The normal blood lactate concentration was measured in the patients. The effect of physical activities results in an increase of stress as 0.5 -1 mmol/L. These patients were critically ill and participants suffering from critical illness were having normal lactate concentration less than 2 mmol/L (Wan, Qin, Wang, Sun, & Liu, 2017).

The higher lactate levels are due to sepsis, anemia, severe congestive heart failure, malignancy, and diabetes. The lactate level changes during exercise and during exercise. During exercise change in the operation of many body parts was observed that includes conversion of aerobic to anaerobic, recovery time, heart rate training zone, and the body responds of an athlete (Wan, Qin, Wang, Sun, & Liu, 2017).

Statistical analysis was conducted by using SPSS, to measure heart rate, lactic acid rate, and peak power in the body.

Results of Muscle fatigue

Peak power pairwise comparison of Muscle fatigue

In case of peak power produced in the muscles after repeated sprints are 539.79 for Hotelling's Trace and Roy's Largest Root while minimum values were observed for Wilk Lambda. In the case of peak power produced in the muscles, the standard deviation was 532.04 ± 154.28. The graph produced in figure 1 shows a decreasing trend in peak values.

The mean and standard deviation for peak power of Muscle fatigue

Figure 1: Reduction of peak power after five sprints

Lactate Acid pairwise comparison of Muscle fatigue

Similar to the trend observed in case of peak power, the production of lactate acid during exercise was higher for Hotelling trace and Roy's largest root as 6990.84. while on the other hand, the minimum value was observed for the Wilks’ Lambda. Standard deviation for the sample 1, 2, 3, 4 and 5 was 2.00 ± .87,          2.52 ± 1.04, 3.28 ± .76, 5.32 ± 2.09, 7.52 ± 3.38, and 10.98 ± 4.35 respectively.

The mean and standard deviation for lactic acid of Muscle fatigue

Test of heart rate of Muscle fatigue

A similar trend was observed in case of heart rate, during exercise heart rate changes and increases with an increase in the exercise. In the results, higher values were observed for Hotelling trace and Roy’s largest. while on the other hand, the minimum value was observed for the Wilks' Lambda. Mean and Standard deviation measured for the sample 1, 2, 3, 4 and 5 was 115.83 ± 14.13, 151.67 ± 22.36, 167.83 ± 13.08, 173.83 ± 9.87, 178.17 ± 7.57, and 178.50 ± 6.22 respectively.

The mean and standard deviation for Heart Rate of Muscle fatigue

Figure 2: Multivariate Tests for Heart Rate

Figure 3: Mean lactate level after each sprint

Discussion on Muscle fatigue

In the present analysis, factors having an influence on muscle fatigue and repeated sprints are used to be analyzed. The muscle fatigue started after the initial sprint and change in the performance was correlated. The results show greater change is observed in the muscle metabolism process and after the second sprint higher anaerobic contribution. The larger performance parameters are measured for the anaerobic power and less reliance is implemented. The higher fatigue resistance is observed during the intermittent sprint exercise (Selmi, Haj, Haj, Moalla, & Elloumi, 2016). The force production in the muscles is observed that changes the anaerobic process towards the aerobic process. The higher fatigue resistance is observed during the metabolic process. The force generated during movement causes sprint mechanical output and performance decrements for the muscles. The power decrement was observed for the metabolic process for force production. In the case of the initial sprint, mechanical output fatigue muscle contraction is observed (Wan, Qin, Wang, Sun, & Liu, 2017). The results show that there is higher cycling for moderate aerobically trained exercise performance. The mechanism of fatigue production in the muscles is different on the bases of the working process and time span for the process. In the present running protocols, fatigue development was for the intermittent sprint exercise (Wan, Qin, Wang, Sun, & Liu, 2017). The fatigue resistance changes during the intermittent sprint exercise and the whole process uses a distribution that is a number of repetitions during the process. The generation of repeated sprints results in muscle fatigue and depends on the recovery pattern, number of repetitions, nature of duration, intensity, and the recovery process between sequence of sprints. The passive recovery of muscles from fatigue depends on the higher degree of fatigue recovery (Girard, Mendez-Villanueva, & Bishop, 2011).

Conclusion on Muscle fatigue

In the present effect of repeated exercise on the muscle is measured. The factors affecting muscle fatigue are training status, the time span of exercise, and the influence of intermitted sprint performance. the aim of the present research was to measure recovery time of muscles, aerobic to anaerobic,  heart rate training zone, and the body responds of the athlete to different levels of exercise. In the results, smaller fatigue values are associated with the aerobic training of muscles. During the intermittent sprint exercise, the inability for body muscles is also observed that reduces the performance of muscles. The manifested decline is observed for the sprint speed and the mean power output in the cycling. The extensive analysis was conducted for the study of the failure of muscles after full activation and contracting muscles. The principal factors proposed in the present analyses is the limitation of the energy supply such as PCR content and oxygen consumption in the muscles and the accumulation of different types of by-products in the metabolism process.

References of Muscle fatigue

Bishop, D. J. (2012). Fatigue during intermittent-sprint exercise. Proceedings of the Australian Physiological Society, 43(01), 9-15.

Bogdanis, G. C. (2012). Effects of Physical Activity and Inactivity on Muscle Fatigue. Front Physiol, 03(142), 142-150.

Girard, O., Mendez-Villanueva, A., & Bishop, D. (2011). Repeated-Sprint Ability – Part I. REVIEW ARTICLE, 41(08), 673-694.

Selmi, M., Haj, S. R., Haj, Y. M., Moalla, W., & Elloumi, M. (2016). Effect of between-set recovery durations on repeated sprint ability in young soccer players. Biol Sport, 33(02), 165-172.

Wan, J.-j., Qin, Z., Wang, P.-y., Sun, Y., & Liu, X. (2017). Muscle fatigue: general understanding and treatment. Exp Mol Med, 49(10), 384-390