Leptin, Ghrelin, Irisin, Asprosin and Subfatin Changes in Obese Women: Effect of Exercise and Different Nutrition Types.

Background and Objectives: In this study, the effects of a six-week training program and various diets on subfatin, asprosin, irisin, leptin, ghrelin and the lipid profile were investigated in overweight women. Materials and Methods: A total of 78 women voluntarily participated in the study. Groups: The study was divided into eight groups: Healthy Control, Obese Control, Obese + Vegetarian, Obese + Ketogenic, Obese + Intermittent Fasting, Obese + Exercise + Vegetarian, Obese + Exercise + Ketogenic and Obese + Exercise + Intermittent Fasting. While there was no intervention in the healthy and obese control groups, the other groups followed predetermined exercise and diet programs for 6 weeks. Blood samples were taken from the participants in the research group twice (before and after the interventions). An autoanalyzer was used to determine the lipid profile in the blood samples taken, and the ELISA method was used to analyze other parameters. Results: Overall, a significant difference was found in the values of weight, BMI, subfatin, ghrelin, leptin, cholesterol, triglyceride, HDL and LDL as a result of the exercise and diet interventions (p < 0.05). There was no significant difference in asprosin and irisin values (p > 0.05). Conclusions: In conclusion, regular exercise and dietary interventions in obese women can regulate lipid profile, ghrelin, leptin and asprosin levels, and increasing irisin with exercise can activate lipid metabolism and support positive changes in lean mass.

The Effect of Breastfeeding and an Intensive Breast Milk Nutritional Support Program on Hospitalization Rates for Hyperbilirubinemia in Term Newborns: An Open Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to determine the effect of breastfeeding and intensive breast milk nutritional support program (IBNSP) on hospitalization rates for hyperbilirubinemia in normal term newborns. METHODS: This study's sample consisted of 68 newborn infants (experimental group: 34; control group: 34) born at a university hospital from October 2020 to April 2021. Five steps of breastfeeding and IBNSP were administered to the experimental group for the first 48 h after birth. This program starts at the postpartum first hour and continues until the 48th hour. It includes face-to-face training, practical support on breastfeeding, and one-to-one demonstration and practice methods. The control group received the standard care recommended by the World Health Organization. Both groups' bilirubin levels were measured 24 and 72 h after birth. Participants in both groups were hospitalized for risky (according to bilirubin values) situations. The groups' bilirubin levels and hospitalization rates for hyperbilirubinemia were compared. RESULTS: There was no statistically significant difference between the experimental (5.19 ± 1.27) and the control (5.83 ± 1.52) groups' bilirubin levels at 24 h after birth, (t = -1.881, p = 0.064); however, the control group infants (12.03 ± 3.67 mg/dl) had higher bilirubin levels than the infants in the experimental group 72 h after birth (9.55 ± 2.82 mg/dl) (t = -3.122, p = 0.003). The experimental group's hospitalization rate for hyperbilirubinemia (n: 1, 2.9%) was lower than the control group's rate (n: 8, 23.5%), and this difference was statistically significant (X2 = 6.275, p = 0.014). CONCLUSIONS: Breastfeeding and IBNSP effectively prevent hospitalization for hyperbilirubinemia and reduce newborns' bilirubin levels.

The effect of nurse support and social support on fatigue experienced by mothers whose children are hospitalized.

The authors' aim in this study was carried out to determine the effect of social support and nurse support on fatigue experienced by mothers whose children were hospitalized. This is a descriptive, analytical and cross-sectional research study. Our study population consisted of all the mothers (n = 198) who had children hospitalized in the pediatric services of the public and training and research hospitals. Data were collected using a questionnaire, Nurse Parent Support Tool, Multidimensional Scale of Perceived Social Support and Brief Fatigue Inventory. Our finding the mothers accompanying their hospitalized children who received adequate nurse support were found to have less maternal fatigue.

The effect of 6-week zinc supplement and weight training on the blood lipids of the sedentaries and athletes.

In this study, we aimed to investigate the effect of 6 weeks of zinc supplementation and weight training on blood lipids of sedentary and athletes. Research group consists of total 40 males; 20 athletes who do regularly physical exercises and 20 sedentary volunteers. The volunteers were divided into four groups. These groups were constituted in that way: the first group is a natural sedentary group which called control group as well (S); the second group is another sedentary group which is supplied with only zinc (Z+S); the third group is training group which composing of athletes and is supplied with zinc (Z+T); the fourth group is the natural training group or athletes (T). From the beginning of the study to the end of 6-weeks of training, the participants gave blood samples before and after every application order to measure the total cholesterol, LDL cholesterol and HDL cholesterol and the levels of Triglyceride. This study identifies that the values of the total cholesterol, LDL cholesterol and Triglyceride of the groups which were supplied with zinc supplement decreased, whereas the levels of HDL cholesterol increased in these groups. Consequently, this work demonstrates that the 6-weeks zinc supplement and training can make a significant contribution to the performance by changing positively the levels of blood lipid.

L-Carnitine supplementation increases expression of PPAR-γ and glucose transporters in skeletal muscle of chronically and acutely exercised rats.

In this study, the effects of L-Carnitine supplementation on the lipid peroxidation and expression of PPAR-γ and glucose transporters in the liver and muscles of chronically and acutely exercised rats were investigated. A total of 42 male Wistar Albino rats (8-week-old) were divided into six groups as follows: Control, L-Carnitine, Chronic Exercise (CE), Chronic Exercise + L-Carnitine, Acute Exercise (AE) and L-Carnitine + Acute Exercise. Chronic exercise consists of 30 m/min, 30 min/day, and 5 days/week for 6 weeks. Rats in the acute exercise groups were run on the treadmill at 30 m/min until exhaustion. L-Carnitine was given at the level of 300 mg per kilogram of diet for 6 weeks. There was no significant difference in the levels of serum ALT, AST, urea, creatinine and glucose levels between the exercise and L-Carnitine groups (P > 0.05). Cholesterol and triglyceride levels decreased by L- carnitine supplementation and chronic exercise in control groups but increased in the AE groups compared to the control group without reinforcement (P < 0.05). Serum, muscle, heart, and liver malondialdehyde (MDA) concentrations were lower in CE and higher in the AE groups (P < 0.001). However, L-Carnitine supplementation reduced MDA levels (P < 0.05). Liver and muscle PPAR-γ, liver GLUT-2 and muscle GLUT-4 mRNA expressions were lower in AE group than in all other groups (P < 0.001). Both chronic exercise and supplemental L-Carnitine increased liver and muscle PPAR-γ, GLUT-2 and GLUT-4 mRNA expression (P <0.05). As a result, although acute exercise increased oxidative stress, chronic exercise reduced oxidative stress by lowering lipid peroxidation level. L-Carnitine supplementation decreased oxidative stress and improved glucose and lipid metabolism by regulation of PPAR-γ, GLUT-2 and GLUT-4 mRNA expression in rats.

Coenzyme Q10 Supplementation Modulates NFκB and Nrf2 Pathways in Exercise Training.

This study reports the effects of Q10, coenzyme Q10 or ubiquinone, a component of the electron transport chain in mitochondria, on nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), inhibitors of kappa B (IκB), nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and hemeoxygenase 1 (HO-1) in rats after chronic exercise training for 6 weeks. 8-week old male Wistar rats were assigned randomly to one of four treatments planned in a 2 x 2 factorial arrangement of two condition (sedentary vs. exercise training), and two coenzyme Q10 levels (0 and 300 mg/kg per day for 6 weeks). The expression levels of the target proteins were determined in the heart, liver and muscle, and biochemical parameters including creatinine, urea, glucose and lipid profile were investigated in plasma. When compared with sedentary group, significant decreases in heart, liver and muscle NFκB levels by 45%, 26% and 44% were observed in Q10 supplemented rats after exercise training, respectively, while the inhibitory protein IκB increased by 179%, 111% and 127% in heart, liver and muscle tissues. Q10 supplementation caused an increase in Nrf2 (167%, 165% and 90%) and HO-1 (107%, 156% and 114%) after exercise training in heart, liver and muscle tissues (p < 0.05). No significant change was observed in any of the parameters associated with protein, carbohydrate and lipid metabolism, except that exercise caused a decrease in plasma triglyceride, which was further decreased by Q10. In conclusion, these results suggest that Q10 modulates the expression of NFκB, IκB, Nrf2 and HO-1 in exercise training, indicating an anti-inflammatory effect of Q10 and emphasizes its role in antioxidant defense. Key pointsCoenzyme Q10 is a component of the electron transport chain in mitochondria which is linked to the generation of energy in the cell.Coenzyme Q10 may inhibit the peroxidation of lipids, thus acting as an antioxidant and protects tissue against oxidative injury.Using of coenzyme Q10 can significantly elevate IκB, Nrf2 and HO-1 and reduce NFκB during exercise training.

Effects of an energy drink on myonectin in the liver, kidney and skeletal muscle of exercised rats.

Myonectin is a hormone that is produced mainly by skeletal muscle. We investigated the effects of exercise and energy drink (ED) administration on myonectin expression in skeletal muscle, liver and kidney tissue in rats; myonectin is produced by all three tissues. We used 28 male albino rats in four groups: untreated control (C), exercise (E), energy drink (ED) and exercise + energy drink (E + ED). The E and E + ED groups were exercised using a treadmill for 4 weeks. We also administered 3.5 ml/kg/day ED during week 1, 7 ml/kg/day during week 2 and 10 ml/kg/day during weeks 3 and 4 in the E and E + ED groups. We used ELISA to measure the levels of myonectin in skeletal muscle, liver and kidney tissues. We used immunohistochemical staining to investigate the localization and intensity of myonectin in these tissues. The amount of myonectin in skeletal muscle tissue was increased significantly in all experimental groups compared to group C. The amount of myonectin in the ED group was significantly greater than group E. No significant difference was observed in liver tissue; however, the amount of myonectin in the liver of group C was the greatest among all groups. The amount of myonectin in kidney tissue exhibited no significant difference among groups. Consumption of ED during exercise increased the amount of myonectin in kidney and skeletal muscle tissues and decreased it in liver tissue. We suggest that consumption of ED might adapt metabolism to incresed exercise by controling synthesis of myonectin in liver, kidney and skeletal muscle.

Effects of irisin and exercise on adropin and betatrophin in a new metabolic syndrome model.

Metabolic syndrome (MetS) is a prevalent public health problem. Uric acid (UA) is increased by MetS. We investigated whether administration of UA and 10% fructose (F) would accelerate MetS formation and we also determined the effects of irisin and exercise. We used seven groups of rats. Group 1 (control); group 2 (sham); group 3 (10% F); group 4 (1% UA); group 5 (2% UA); group 6 (10% F + 1% UA); and Group 7, (10% F + 2% UA). After induction of MetS (groups 3 -7), Group 3 was divided into three subgroups: 3A, no further treatment; 3B, irisin treatment; 3C, irisin treatment + exercise. Group 4, 1% UA, which was divided into three subgroups: 4A, no further treatment; 4B, irisin treatment; 4C, Irisin treatment + exercise. Group 5, 2% UA, which was divided into three subgroups: 5A, no further treatment; 5B, irisin treatment; 5C, irisin treatment + exercise. Group 6, 10% F + 1% UA, which was divided into three subgroups: 6A, no further treatment; 6B, irisin treatment; 6C, irisin treatment + exercise. Group 7, 10% F + 2% UA, which was divided into three subgroups: 7A, no further treatment; 7B, irisin treatment; 7C, irisin treatment + exercise., Irisin was administered 10 ng/kg irisin intraperitoneally on Monday, Wednesday, Friday, Sunday each week for 1 month. The exercise animals (in addition to irisin treatment) also were run on a treadmill for 45 min on Monday, Wednesday, Friday, Sunday each week for 1 month. The rats were sacrificed and samples of liver, heart, kidney, pancreas, skeletal muscles and blood were obtained. The amounts of adropin (ADR) and betatrophin in the tissue supernatant and blood were measured using an ELISA method. Immunohistochemistry was used to detect ADR and betatrophin expression in situ in tissue samples. The duration of these experiments varied from 3 and 10 weeks. The order of development of MetS was: group 7, 3 weeks; group 6, 4 weeks; group 5, 6 weeks; group 4, 7 weeks; group 3, 10 weeks. Kidney, liver, heart, pancreas and skeletal muscle tissues are sources of adropin and betatrophin. In these tissues and in the circulation, adropin was decreased significantly, while betatrophin was increased significantly due to MetS; irisin + exercise reversed this situation. We found that the best method for creating a MetS model was F + UA2 supplementation. Our method is rapid and simple. Irisin + exercise was best for preventing MetS.

The role of different exercises in irisin, heat shock protein 70 and some biochemical parameters.

Background: The aim of the study was to determine the effects of different and regularly applied exercise programs on irisin, heat shock protein 70 and some biochemical parameters. Methods: 120 male university students participated in the study. Participants were divided into 4 equal groups as control (C), resistance exercise group (RE), high intensity interval (HIIT) and aerobic exercise group (AE). While the control group did not perform any exercise, the pre-determined exercise programs were applied to the other groups for 8 weeks and 3 days in a week. Blood samples were taken from all participants before and after the exercise program. Cholesterol, High-density Lipoprotein (HDL) and Low-density Lipoprotein (LDL) cholesterol, triglyceride (TG), Creatine kinase (CK), Lactate dehydrogenase (LDH), Irisin and Heat shock protein 70 (HSP70) levels were analyzed in blood samples. Results: It is determined that there are significant differences in pre-posttest values of the AE group's LDH, cholesterol, HDL-cholesterol, TG and HSP 70 levels, HIIT group's CK, LDH, Cholesterol, HDL-cholesterol, TG, Irisin and HSP70 levels and RE group's CK, LDH, Cholesterol, LDL-cholesterol, TG and Irisin levels (p<0.05). Conclusions: It can be said that exercise can provide improvements in lipid profile, changes in HSP70 levels may vary depending on muscle damage, the increase of irisin due to exercise.

Breastfeeding/Breast Milk Safety in Infants of Mothers with Suspected or Confirmed COVID-19 Infection.

The purpose of this systematic review was to determine whether suspected or confirmed COVID-19 infected mothers in the lactation period can breastfeed their infants; and whether suspected or confirmed COVID-19 infected mothers can breastfeed their infants by taking some precautions. The study also aimed to present the measures that can be taken in line with the evidence. The studies conducted after November 2019 and including infants of suspected or confirmed COVID-19 infected mothers were reviewed between 2019 and 2020. A literature review was conducted in five electronic databases (MEDLINE, PubMed, ScienceDirect, Web of Science, and Scopus) to reach original quantitative studies in English. The present authors retrieved 46 of the 1,229 studies included after screening. Three studies were cross-sectional studies, 30 were case studies, and 13 were cohorts. In most of the sources examined, it was concluded that most of the breastfed infants had negative findings for SARS-Cov-2 infection in PCR. In line with the limited data available, it was concluded that most of the breastfed infants had negative findings for SARS-Cov-2 infection in PCR; and breastfeeding mothers should initiate breastfeeding by taking protective measures. Key Words: Breastfeeding, COVID-19, Suspected COVID-19 infected mothers, Confirmed COVID-19 infected mothers.

The effects of chromium picolinate on glucose and lipid metabolism in running rats.

BACKGROUND: Chromium picolinate (CrPic) is commonly used to reduce muscle fatigue after exercise. We aimed to elucidate the effects of CrPic on glucose and lipid metabolism and the expression of glucose transporters in exercised rats. METHODS: Forty-two male Wistar rats (8-week-old) were distributed into six groups (n = 7) as follows: Control, CrPic, Chronic Exercise (CEx), CEx + CrPic, Acute Exercise (AEx), and AEx + CrPic. CEx consists of 30 m/min, 30 min/day, and 5 days/week for 6 weeks. CrPic was supplemented at 400 µg elemental Cr/kg of diet for 6 weeks. In the AEx groups, animals were run on the treadmill at 30 m/min until exhaustion. RESULTS: CEx significantly lowered blood glucose (BG), total cholesterol (TC) and triglyceride (TG) levels, but elevated insulin concentration (IC), compared with control (P < 0.05). CEx significantly decreased the level of malondialdehyde (MDA) in the serum, liver, and muscle while AEx elevated it (P < 0.001 for all). CrPic significantly decreased BG, TC, TG levels, and increased IC with a remarkable effect in CEx rats (P < 0.01). CrPic also significantly reduced serum, liver, and muscle MDA levels (P < 0.001). Both AEx and CEx increased the expression of liver glucose transporter 2 (GLUT-2) and muscle GLUT-4 with the highest level in CEx rats (P < 0.05). Moreover, CrPic supplementation significantly elevated GLUT-2 and GLUT-4 expressions in the liver and muscle of sedentary and exercise-treated rats (P < 0.05). CONCLUSION: CrPic improves various metabolic parameters and reduces oxidative stress in CEx and AEx rats by decreasing BG, TC, TG, MDA levels in serum and elevating GLUT-2 and GLUT-4 expression in the liver and muscle samples. The efficacy of CrPic was more pronounced in CEx rats.

Adrenocorticotropic hormone and cortisol levels in athletes and sedentary subjects at rest and exhaustion: effects of magnesium supplementation.

The effects of a 1-month exercise program and magnesium supplementation on the adrenocorticotropic hormone and cortisol levels were studied in young tae-kwon-do and sedentary subjects both at rest and exhaustion. The hormone levels were compared before and after supplementation with 10 mg of magnesium (as magnesium sulfate) per kilogram of body weight. Both exercise and magnesium supplements caused significant increases of the adrenocorticotropic hormone (p < 0.05). The cortisol levels were increased in training subjects receiving supplements (p < 0.05) but not so in subjects that either trained or received magnesium supplements in an independent manner. The cortisol levels measured in resting individuals were higher in the supplemented and non-supplemented athletes than those in sedentary subjects (p < 0.05). The results of this study show that exercise and/or magnesium supplementation causes a rise of the adrenocorticotropic hormone, whereas cortisol is increased only as a result of combined exhaustion and magnesium supplements.

The effect of magnesium supplementation on glucose and insulin levels of tae-kwan-do sportsmen and sedentary subjects.

This study was performed to determine how the magnesium supplementation for a 4-week period affects the glucose and insulin levels at rest and at exhaustion in sportsmen. This is a 4 week study performed on 30 healthy male subjects varying between 18-22 ages. Subjects were separated into 3 groups. 1st group; group supplemented with magnesium, 2nd group; Magnesium supplementations exercise group, 3rd group; training group. Glucose and insulin parameters of the groups were measured 4 times; at rest and exhaustion in the beginning of the research and at rest and exhaustion after the end of 4 weeks application period. Glucose levels in exhaustion measurements both before and after the supplementation significantly increased compared to resting levels (p<0.05). Significant difference was determined in the glucose values of 1st and 2nd groups supplemented with magnesium in comparison to their first measurements (p<0.05). Insulin values a decrease in all of the 3 groups occurred with exercise both before and after the supplementation (p<0.05). Magnesium supplementation has an important effect on glucose levels whereas it has no effect on insulin levels.

The effects of coenzyme Q10 on oxidative stress and heat shock proteins in rats subjected to acute and chronic exercise.

PURPOSE: The aim of the study was to determine the effects of dietary CoQ10 on serum biochemical parameters, lipid peroxidation, and HSP expression in the liver and slow-twitch muscles (soleus and gastronemius deep portion) of exercise-trained rats. METHODS: A total of 42 Wistar albino rats were divided into six groups: 1) Control, 2) Coenzyme Q10 (CoQ10), 3) Chronic Exercise (CE), 4) CE + CoQ10, 5) Acute Exercise (AE), and 6) AE + CoQ10. The rats were subjected to the running test 5 days a week for 6 weeks after which CoQ10 was administered via the diet. AE (running on the treadmill until the rats were exhausted) was done on the last day. RESULTS: The results showed no significant difference in serum glucose and liver functions in any of the groups. However, CoQ10 and exercise treatment were found to lower cholesterol and triglyceride levels. Serum and muscle malondialdehyde (MDA) levels were found to be lower in the CE and CE + CoQ10 groups compared to the control group. The highest levels of HSP60, HSP70, and HSP90 in liver and muscle were found in the AE group, and the lowest levels were found in CE + CoQ10 group. CoQ10 supplementation reduced HSP expression in both CE- and AE-trained rats (P < 0.05). CONCLUSION: The results showed that CoQ10 supplementation could reduce MDA levels, protect against oxidative damage, and regulate HSP expression in CE- and AE-trained rats. CE and CoQ10 were shown to reduce oxidative stress synergistically.

Biotin and chromium histidinate improve glucose metabolism and proteins expression levels of IRS-1, PPAR-γ, and NF-κB in exercise-trained rats.

BACKGROUND: Chromium histidinate (CrHis) and biotin are micronutrients commonly used to improve health by athletes and control glycaemia by patients with diabetes. This study investigates the effects of 8-week regular exercise training in rats together with dietary CrHis and biotin supplementation on glucose, lipids and transaminases levels, as well as protein expression levels of peroxisome proliferator-activated receptor gamma (PPAR-γ), insulin receptor substrate-1 (IRS-1) and nuclear transcription factor kappa B (NF-κB). METHODS: A total of 56 male Wistar rats were randomly divided into 8 groups of 7 animals each and treated as follows: Control, CrHis, Biotin, CrHis+Biotin, Exercise, CrHis+Exercise, Biotin+Exercise, and CrHis+Biotin+Exercise. The doses of CrHis and biotin were 400 µg/kg and 6 mg/kg of diet, respectively. The training program consisted of running at 30 m/min for 30 min/day at 0% grade level, 5 days per week, once a day for 6 weeks. Serum glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL), triglycerides (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured with an automatic biochemical analyzer. Muscle and liver PPAR-γ, IRS-1 and NF-κB expressions were detected with real-time polymerase chain reaction. RESULTS: Regular exercise significantly (p < 0.001) decreased glucose, TC and TG levels, but increased HDL cholesterol. Dietary CrHis and biotin supplementation exhibited a significant (p < 0.001) decrease in glucose (effect size = large; ƞ2 = 0.773) and TG (effect size = large; ƞ2 = 0.802) levels, and increase in HDL cholesterol compared with the exercise group. No significant change in AST and ALT (effect size = none) levels was recorded in all groups (p > 0.05). CrHis/biotin improves the proteins expression levels of IRS-1, PPAR-γ, and NF-κB (effect size: large for all) in the liver and muscle of sedentary and regular exercise-trained rats (p < 0.001). CONCLUSIONS: CrHis/biotin supplementation improved serum glucose and lipid levels as well as proteins expression levels of PPAR-γ, IRS-1 and NF-κB in the liver and muscle of exercise-trained rats, with the highest efficiency when administered together. CrHis/biotin may represent an effective nutritional therapy to improve health.

The effects of magnesium supplementation on thyroid hormones of sedentars and Tae-Kwon-Do sportsperson at resting and exhaustion.

The effect of magnesium on thyroid hormones of sedentars and sportsperson in Tae-Kwon-Do, has been investigated in a 4-weeks training program. Group 1 consisted of sedentars receiving 10 mg/kg/day Mg for 4 weeks. Group 2 consisted of subjects receiving magnesium (Mg) supplement and practicing Tae-Kwon-Do for 90-120 min/day, for five days a week. Group 3 consisted of subjects practicing Tae-Kwon-Do but receiving Mg supplements. TSH levels increased with training and Mg supplementation (p<0.05). Mg increased FT3 values. (p<0.05). TT3 values of groups reduced in all groups (p<005). After supplementation, group 1 had higher TT4 values than groups 1 and 3 and the group 2 had higher TT4 values than the third group (p<005). Results of this research show that training until exhaustion causes reduction in thyroid hormone activity in sedentars and sportsperson. It has been established that Mg supplementation however, prevents reduction in thyroid hormone activity in sedentars and sportsperson.

Effects of magnesium supplementation on blood parameters of athletes at rest and after exercise.

The effects of magnesium supplementation on blood parameters were studied during a period of 4 wk in adult tae-kwon-do athletes at rest and exhaustion. Thirty healthy subjects of ages ranging in age from 18 to 22 yr were included in the study. The subjects were separated into three groups, as follows: Group 1 consisted of subjects who did not train receiving 10 mg/kg/d magnesium. Group 2 included subjects equally supplemented with magnesium and exercising 90-120 min/d for 5 d/wk. Group 3 were subject to the same exercise regime but did not receive magnesium supplements. The leukocyte count (WBC) was significantly higher in groups 1 and 2 than in the subjects who did not receive any supplements (p < 0.05). There were no significant differences in the WBC of the two groups under magnesium supplementation. The erythrocyte, hemoglobin, and trombocyte levels were significantly increased in all groups (p < 0.05), but the hematocrit levels did not show any differences between the groups although they were increased after supplementation and exercise. These results suggest that magnesium supplementation positively influences the performance of training athletes by increasing erythrocyte and hemoglobin levels.

Effect of magnesium supplementation on some plasma elements in athletes at rest and exhaustion.

The effects of magnesium supplementation on plasma magnesium, zinc, and copper levels were determined in young adult tae-kwon-do athletes and sedentary controls at rest and exhaustion. After a 4-week supplementation period with 10 mg/day/kg Mg, the plasma magnesium, copper, and zinc levels significantly increased in sedentary and training (90-120 min training 5 days a week) subjects when compared to nonsupplemented controls (p < 0.05).

Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion.

This study was performed to assess how 4 weeks of magnesium supplementation and exercise affect the free and total plasma testosterone levels of sportsmen practicing tae kwon do and sedentary controls at rest and after exhaustion. The testosterone levels were determined at four different periods: resting before supplementation, exhaustion before supplementation, resting after supplementation, and exhaustion after supplementation in three study groups, which are as follows: Group 1-sedentary controls supplemented with 10 mg magnesium per kilogram body weight. Group 2-tae kwon do athletes practicing 90-120 min/day supplemented with 10 mg magnesium per kilogram body weight. Group 3-tae kwon do athletes practicing 90-120 min/day receiving no magnesium supplements. The free plasma testosterone levels increased at exhaustion before and after supplementation compared to resting levels. Exercise also increased testosterone levels relative to sedentary subjects. Similar increases were observed for total testosterone. Our results show that supplementation with magnesium increases free and total testosterone values in sedentary and in athletes. The increases are higher in those who exercise than in sedentary individuals.

Calcium supplementation and 4-week exercise on blood parameters of athletes at rest and exhaustion.

In the present study, experiments were designed to investigate if supplementation with calcium during 4 weeks had an effect on blood parameters in sedentary male athletes at rest and exhaustion. Thirty healthy subjects of ages ranging from 18 to 22 years were included in the study. The subjects were separated into three groups, as follows: Group 1 consisted sedentary athletes receiving 35 mg/kg/day calcium gluconate. Group 2 included subjects equally supplemented with calcium training 90 min/day for 5 days/week. Group 3 were subject to the same exercise regime but did not receive calcium supplements. Blood parameters were determined in the experimental subjects at rest and after exhaustion. The leukocyte count (WBC) of athletes in groups 2 and 3 were significantly higher at exhaustion (p < 0.05). There were no significant differences in the WBC of the two supplemented groups. The erythrocyte count (RBC) was increased in the supplemented athletes after training (p < 0.05), but hemoglobin, hematocrit, and thrombocyte levels remained unchanged. The mean corpuscular volume increased in the calcium-supplemented group at rest (p < 0.05). These results suggest that calcium supplementation only causes increases in white and red blood cell counts in athletes after exhaustion while other hematological parameters remain unchanged.