THE EFFECT OF HIGH-INTENSITY EXERCISE TRAINING ON SERUM CALCIUM OF FEMALE COMBAT ATHLETES

Cell homeostasis is an essential factor in maintaining cellular health and intracellular mechanisms, which can also be associated with inflammatory factors and increased stress for muscle cell health. Calcium is also a necessary factor in cell health and is to establish homeostasis in the body. This study aimed to investigate the effect of high-intensity training on serum calcium levels in combat women. For this purpose, 18 women karateka in the age range of 17 to 23 years were randomly divided into 2 groups: control (n=7) and exercise ((n=11). The exercise group performed proper exercises to improve karate and aerobic techniques for 6 weeks in the intensities of more than 80% of the maximum heart rate reserve. Physiological indices and blood samples were measured 24 hours before and 48 hours after the training protocol. To measure calcium cell biomarker, the Pars Azmoon calcium kit was used. Research data were analysed by covariance test at the significant level (P≤0.05) using SPSS software version 25. After six weeks of high-intensity training, there was a significant difference in serum calcium levels in the exercise group compared to the control group (P = 0.002). Also, the results within the group showed a significant increase in serum calcium (P = 0.016) in the exercise group compared to baseline conditions. High intensity training seems to increase serum calcium in female athletes, and this can lead to precursors to cellular disorders, muscle damage and increase inflammatory factors and ultimately decrease the performance of female athletes. However, more research is essential in this regard


INTRODUCTION
Calcium (Ca) is the most abundant mineral in the human body. It has also been shown that exercise can make a significant difference in blood calcium levels (Ramazanpour et al. 2020). Calcium also plays a significant role in cell health, including the nerves function, blood coagulates, cardiac function, and .muscle contractions. There are three distinct fractions of calcium in the blood: free calcium (48%), protein-bind calcium (40%), and calcium bind to inorganic anions (12%). Increased levels of calcium ions in the blood cause factors such as weakness, lack of energy, anorexia, nausea and vomiting, constipation, abdominal pain, and urination in large quantities. Calcium release during stress and executes by Translokon (proteins involved in translation). In martial arts, muscle injury is known. Because karate is a collision sport, Jurnal Stamina Vol. 6 (2), 2023 Ravesh SMH, Moghadam MN it exposes athletes to more injuries by using foot and hand kicks (Shirvani et al. 2015). Karateka women with properties less muscle mass, higher fat percentage, and hormonal changes, are more vulnerable than Karateka men. Hence, one of the serious discussions in the science of karate practice is the culmination of necessary world-class sports skills. Usually, karate women try to reach the peak of performance before the main competitions by doing high-intensity exercises. With insufficient alternation between performances and rehearsals and with short stages of reconstruction, they are subjected to over-training. Therefore, this type of training intensity and stress in the peak of performance, has been accepted by trainers, leading to increased markers and As, Jing et al. (2021) reported that 8 weeks of resistance exercise by mice increased calcium enzyme concentrations. Also, some researchers reported that six weeks of resistance exercise insignificant increased calcium levels Parhampour et al (2023) . In this relation, higher concentrations of total calcium and calcium ionization in active people have been reported compared to the control group (Maimoun L., and Sultan C., 2019).
However, lampchert et al. (2014) reported a decrease in intracellular ATP and dysfunction of the calcium pump, and therefore an increase of intracellular calcium concentration. Given the biological importance of calcium in establishing intracellular homeostasis and muscle contractions, as well as stimulating some of the cellular signaling pathways, the question arises as to how intense karate training increase the serum calcium concentration in women who practice karate. Therefore, the aim of the present study was to evaluate the serum calcium concentration during 6 weeks of intense training in karate women.

RESEARCH METHODOLOGY
The statistical population of the present study consists of practicing karate girls in the age group of 17 to 21. Subjects randomly divided into two groups of exercise (n = 11) and control (n = 7). The subjects filled out health and physical activity questionnaires. They were examined by the Jurnal Stamina Vol. 6 (2), 2023 Ravesh SMH, Moghadam MN team doctor, and after obtaining the inclusion criteria, including having one of the bronze, silver, or gold medals in international or national competitions, no history of drug use, regular participation in karate training, no history of long-term injury and no use of analgesics and inflammation drugs that affect serum calcium concentrations, participated in this study. Exclusion criteria is included sports injuries such as ruptured ligaments and meniscus, fractures, dislocations during exercise and additional exercise outside the training protocol, leaving the camp, irregular participation in exercise, and taking anti-inflammatory drugs and calcium supplements or supplements during the period of study (Maleki and Tartibian, 2018).
The blood sampling stage was performed under the supervision of trained personnel. 8 cc of fasting venous peripheral blood samples at 08:00-09:00 were collected in fasting conditions 24 hours before the start of training and 48 hours after the end of the six weeks exercises. To separate serum, blood samples after clotting for 15 minutes at room temperature, were centrifuged at 3000 rpm for 15 minutes at 4 ° C and serum calcium levels (mg/dl) were assessed by the standard automatic autoanalyzer -BT 1500 system by Pars Azmoun Biochemistry Kit.
Results are expressed as mean ± standard deviation (SD). Shapiro1 test was used to determine the natural distribution of data. ANCOVA analysis of covariance was used to test the research hypotheses. SPSS software version 25 was used for data processing at the significance level (P <0.05).

RESEARCH RESULTS
In the Exgroup, body fat percentage, systolic blood pressure, and resting heart rate decreased (p<0.05) but, maximum heart rate and Vo2max significantly increased (p<0.05). Also weight and diastolic blood pressure none significantly decreased after 6 wks of high-intensity exercises in the Ex group.

Serum Calcium
After six weeks of karate training of competition season, there was a significant difference in serum calcium levels ( = 0.496 and P = 0.002) in the exercise group compared to the control group. (Figure 2) Also, the within-group results showed a significant increase in serum calcium levels (P = 0.016) only in the exercise group compared to baseline conditions ( Figure 2). In addition, there was a linear relationship between the auxiliary random variable and the serum calcium levels (Picture 1).
Picture 1. Serum Calcium levels of trained karateka girls, following six weeks of high-intensity exercises

DISCUSSION
The results showed that 6 weeks of high-intensity karate exercises increased serum calcium of karateka women, and this change correlated with an auxiliary random variable. This data clearly showed that the high intensity of Karate exercises leads to cellular stress. The results of this study also showed that physiological and anthropometric factors changed after 6 weeks. Fat percentage, blood pressure, and resting heart rate decreased after 6 weeks of high-intensity exercise of karate, and maximal heart rate and maximal oxygen consumption increased. Researchers reported the increase of serum calcium and decrease of physiological characteristics (Fat percentage, blood pressure, and resting heart rate) after 6-12 weeks high-intensity exercises (  In the ER pathway, caspase-3 is activated through an ER-located caspase, caspase-12  . Caspase-12 is predominately situated at the cytosolic side of the ER membrane, and is specifically activated by disturbance to ER homeostasis, such as ER Ca2+ depletion. The activation of caspase-12 has been shown to depend on a Ca2+-dependent protease calpain . In addition, the ER can regulate the apoptotic signaling 8 through IP3 receptor (IP3R) or ryanodine receptor (RyR) mediated by Ca release 2+ There is this guess that with increasing serum calcium the health of athletes is endangered, and the role of inflammatory and stressors in the continuation of the path should be examined by exercise physiologists.

CONCLUSION
In conclusion, the results of the present study show serum calcium is affected by highintensity karate exercises, and it increases significantly. Little researches have been studies on response such exercises on karateka women. These observations suggest that the high-intensity karate exercises could be taken into consideration when investigating cell stress responses to exercise training in Karateka women. It remains to be determined how changes in calcium levels of karateka women function may be connected with cell stress outcomes in these athletes.