MAGNESIO Y DEPORTES

Acta Physiologica Hungarica, Volume 93 (2–3), pp. 137–144 (2006) DOI: 10.1556/APhysiol.93.2006.2-3.4

The effect of magnesium supplementation on lactate levels of sportsmen and sedanter V Çınar1*, M Nizamlıo lu2, R Mo ulkoc3 1 High

School of Physical Education and Sport of Karaman, Selcuk University, Karaman, Turkey of Food Hygiene and Technology, Faculty of Veterinary, Selcuk University, Konya, Turkey 3 Department of Physiology, Faculty of Medicine, Selcuk University, Konya, Turkey

2 Department

Received: August 22, 2005 Accepted: May 25, 2006

This study was performed to assess how magnesium supplementation affects plasma lactate levels at rest and exhaustion in sportsmen and sedentary. Research was performed on 30 healthy subjects varying between 18–22 years of age for a four-week period. Subjects were separated into 3 groups: Group 1; sedentary taking magnesium supplementation only (10 mg/kg/day) (Mg + S), Group 2; subjects magnesium supplemented + training 90–120 min 5 days a week (Mg + Training), Group 3; training 90– 120 min 5 days a week.

Lactate levels of the groups were measured 4 times; at rest and exhaustion in the beginning of the research and after the end of the research.

At the end of the research, exhaustion measurements both before and after supplement were found significantly higher than rest measurements in terms of lactate levels (p<0.05). An important decrease was determined in the lactate levels of the 1st and 2nd groups when compared to their first measurements (p<0.05).

The results of this research indicate that lactate increases with exhaustion. However, magnesium supplement may positively affect performance of sportsmen by decreasing their lactate levels.

Keywords: magnesium, exercise, lactate, exhaustion

Two methods are frequently used to assess the interaction between minerals and maintaining the performance. First, when food of various content is given to physical activity participants in order to observe their physiological and performance response; secondly when is effects of physical activity on food values is to be assessed (5). To date the number of elements necessary to life which take part in the structure of organism is over ninety. There has been a great interest on the effects of mineral support

* Corresponding author: Dr. Vedat Cinar; E-mail: cinarvedat@hotmail.com; Fax: + 90 338 228 03 24

0231–424X/$ 20.00 © 2006 Akadémiai Kiadó, Budapest

138

V Çınar et al.

on physical performance. Even more investigations were being carried out to assess the role of one of these elements, magnesium, in human health and physiology during the recent years (2, 3, 6, 9, 18).

Researches have indicated that magnesium insufficiency may decrease the physical performance and magnesium state may influence on exercise capacity (18, 23, 25).

Along with magnesium insufficiency, energy metabolism and physical work capacity may be negatively affected because body magnesium is used during physical exercises.

Magnesium is considered as a substance increasing physical performance (3).

Researches show that magnesium insufficiency decreases physical performance (15). It has been reported that there is a positive relation between magnesium level and physical performance (10, 19). Rude and Ryzen (26) determined that supplementation of potassium and magnesium provided a 10% increase in exercise capacities. Laires and Alves (14) investigated the effect of plasma magnesium level on intense exercises in their studies with 8 trained and 8 untrained swimmers. These researchers observed that plasma magnesium level significantly decreased both trained and untrained sportsmen after swimming. Lactate concentration either slightly decreases or it remain unchanged in exercises with VO2 max intensity lower than 40%. However, the lactate concentration starts changing in muscle and blood, the intensity increases (12). Finstad et al. (9) added daily 212 mg of magnesium to sportswoman during four weeks. At the end of magnesium application they observed that the resting duration and lactic acid levels decreased. When the oarsmen, who were given 360 mg daily magnesium were compared to sportsmen without magnesium support, it was found that oarsmen taking magnesium had used less oxygen and had been less exhausted (1). Finally, lactic acid levels significantly increase in exercises with higher intensity than 75% of VO2 max.

Exercise duration decreases due to increase of lactate. Work duration of a normal person may last between 4–6 minutes due to this (28).

This study was performed to assess the effect of a 4 week-period of magnesium support on plasma lactate levels, at rest and at exhaustion before and after the application in sedentary and sportsmen.

Materials and Methods Thirty healthy subjects whose age varyed between 18–22 years participated in the research. The participants were informed about the content and purpose of this study.

Subjects joined to the study voluntarily.

Subjects were separated into 3 groups, including 10 people each.

Group 1. Sedentary group with magnesium supplementation (Mg+S). The normal diet of subjects was supplemented with Mg sulphate (10 mg/kg/day) and they has no exercise program.

Group 2. Magnesium supplemented and Training group (Mg+Tr).

Group 3. Training group (Tr).

Acta Physiologica Hungarica 93, 2006

Lactate and magnesium supplementation

139

In the 1st and 2nd groups, magnesium sulphate supplement to the normal diet lasted for 4 weeks. Group 2 and Group 3 have done 90–120 minutes of Tae-Kwan-do training five days a week for 4 weeks.

Average age of the 1st group subjects was assessed as 19.9±2.7 (years), and average height as 173.4±6.2 cm, body weight as 68.49±7.2 kg.

Average age of the 2nd group subjects was assessed as 19.3±2.5 (years), and average height as 171.3±7.2 cm, body weight as 67.84±6.9 kg.

Average age of the 3rd group subjects was assessed as 20.3±2.3 (years), and average height as 173.3±6.3 cm, body weight as 68.04±6.9 kg.

Exhaustion measurement At the beginning of the research and after the 4-week supplement period, subjects had to complete a 20 m shuttle run test was to create exhaustion, and exhaustion blood samples were drawn. Test was applied in Selcuk University body training and sports academy sports saloon. Test starts with a slow running speed (8 km/hour) and subject should be on the opposite line in each signal. Subject continues the test if he catches the rhythm in the other signal. If he has difficulty in catching the signal, if he cannot reach 3 m front line at the edge of the track consecutively in 2 tours, the test is over for him. Subjects run in 20 m track by signal, touch the line with one foot. Running speed is increased 0.5 m/minute.

Every minute is a grade. Test result is the grade which subject is stopped and is an indicator of endurance. Length of the test depends on the individual (24).

Lactate measurement Blood samples were taken to heparinized tubes at rest and exhaustion (at the end of maximum aerobic and maximum anaerobic tests). Kit (Randox brand) was used for the measurement of lactate. Lactic acid levels were measured with AU400 brand device and the values were given as mg/dl.

Lactate assessments 1st measurement: resting level before support.

2nd measurement: after exhaustion before support.

3rd measurement: resting level after support.

4th measurement: after exhaustion after support.

Statistical analysis Statistical analyses were done by using the SPSS 11.0 program. Variance analysis was used for the determination of measurement differences between groups and inside the groups; Duncan multiple range test was used for evaluating the results of groups with difference. P<0.05 was considered to be significant.

Acta Physiologica Hungarica 93, 2006

140

V Çınar et al.

Results Plasma lactate levels of study groups are given in Table I. When the lactate measurements of groups were examined, significant difference was found between the resting (I) measurements before support and exhaustion (II) measurements before support of the 1st group (p<0.05). In the 1st group, there is a significant difference between the resting (I) and exhaustion (IV) levels in terms of lactate after supplementation (p<0.05). Significant difference was found between the resting before and after supplement (p<0.05). Likewise, significant difference is determined between the exhaustion levels before and after supplement (p<0.05).

There is significant difference between the resting and exhaustion levels of the 2nd group before supplement (p<0.05). Likewise significant difference is determined between the resting and exhaustion levels of the 2nd group after supplement (p<0.05).

There is significant difference between the resting lactate levels of the 2nd group before and after supplement. There is significant difference between the exhaustion levels before and after the supplement in group 2 (p<0.05).

When the lactate measurements of the 3rd group is examined, significant difference is found between resting and exhaustion levels both before and after supplement (p<0.05). No statistically important difference is found among the other measurements of the 3rd group.

When the lactate levels between the groups in the first measurements were examined, there was no significant difference among the groups (p>0.05).

In the 2nd measurements the levels of 1st and 3rd groups were found similar to each other, whereas the level of the 2nd group was lower than that of the others (p<0.05). In the 3rd measurements, there was no difference between the 2nd and 3rd groups whereas the level of 1st group was lower than the 2nd group (p<0.05). In the 4th measurement the highest level was found in group 3 and the lowest in group 2 (p<0.05).

Table I Plasma lactate levels in groups Measurements L A C (mg/dl) T A T E

I II III IV

1st group (Sedenter) 16.41 ± 1.60 109.70 ± 7.65 ax 13.01 ± 0.85 dy 95.01 ± 8.69 by

2nd group (Mg +Training) 17.72 ± 5.65 100.47 ± 18.12 ay 15.18 ± 7.01 dx 90.34 ± 14.22 bz

3rd group (Training) 16.40 ± 3.90 107.80 ± 22.20 ax 16.01 ± 4.80 bx 105.26 ± 26.60 ax

a, b, c: Differences inside groups with different letters in the same column are important. x, y, z: Differences inside groups with different letters in the same line are important.

I: Resting level before supplement II: Exhaustion level before supplement III: Resting level after supplement IV: Exhaustion level after supplement

Acta Physiologica Hungarica 93, 2006

Lactate and magnesium supplementation

141

Plasma Mg levels are presented in Table II. It was observed that plasma Mg levels increased due to exhaustion and Mg supplementation (P<0.05). However, this increases were lover in training groups than in the sedentary ones (P<0.05).

Table II Plasma Mg levels in groups Levels Mg (mg/dl)

Measurements I II III IV

1st Group (Mg) 1.90 ± 0.10 2.01 ± 0.11 c 2.22 ± 0.15 bx 2.34 ± 0.15 ax

2nd Group (Mg + Training) 1.93 ± 0.13d 2.09 ± 0.14 a 2.12 ± 0.10 by 2.21 ± 0.11 ay

3th Group (Training) 1.88 ± 0.16 b 2.01 ± 0.18 c 1.90 ± 0.12 bz 2.04 ± 0.27 az

a, b, c: Differences inside groups with different letters in the same column are important. x, y, z: Differences inside groups with different letters in the same line are important.

I: Resting levels before supplement II: Exhaustion levels before supplement III: Resting levels after supplement IV: Exhaustion levels after supplement

Discussion Our most important finding has been the decrease in lactate levels at rest and exhaustion period in magnesium supplemented groups. The lactic acid production is increase the metabolism increase with related to activity. The lactate concentration starts change in blood and muscle when the exercise intensity increases over a certain level. Lactic acid levels significantly increase in exercises with higher intensity than 75% of VO2 max.

Exercise duration immediately decreases because of this increase. Work duration of a normal person may last between 4–6 minutes due to this (28).

There has been a great interest on the effects of mineral support on physical performance in the recent years. Research have indicated that magnesium insufficiency may decrease the physical performance. Thus, magnesium situation may affect be exercise capacity (18, 23, 25).

Present findings of our study reveal that there is a significant difference between the resting and exhaustion levels before and after exercise, before and after magnesium support. These findings show that magnesium support has a positive effect on performance by reducing lactate levels even in sedentary people (1st group). However, it has been reported that magnesium support positively affects the performance (10, 19).

In or experiment plasma lactate levels significantly increased in the 2nd group with magnesium support plus training similarly to the previous group at the end of the exercise. However, when the levels of this group were compared to the 2nd group a significant decrease was found especially after exhaustion. When the levels of 3rd only training group were compared with those obtained after the 4-week experiment duration, they revealed significant increases both in terms of resting and exhaustion.

Acta Physiologica Hungarica 93, 2006

142

V Çınar et al.

This reveals a decrease in performance when compared to other groups. It has been reported that there was a decrease in physical capacities as a result of magnesium insufficiency (15). Energy metabolism and physical work capacity may be negatively affected by magnesium insufficiency because body magnesium is used with physical exercises. Magnesium may be considered as a substance increasing physical performance (3). In a study, performed on experiment animals, it was found that magnesium insufficiency decrease oxygen usage by decreasing 2,3-DPG activity and therefore it negatively affected the performance (17). When the oarsmen, who received Mg supplement (360 mg/day) compared to sportsmen without magnesium support, it was found that oarsmen taking magnesium had used less oxygen and had been less exhausted (1). Rude and Ryzen (26) determined a 10% increase in exercise capacities of these people who received were potassium and magnesium supplemented.

In the present literature, however, there are reports which claim that magnesium support has no effect on performance. Thus, Finstad et al. (9) added daily 212 mg of magnesium during four weeks to the diet of sportswomen. At the end of application they observed that magnesium support has a positive effect on blood magnesium levels but had no effect on physical performance and the rearrangement of the body after exercise. A similar finding was reported by Newhouse and Finstad (22). Another study reported that K-Mg aspartate support did not affect the power and strength of sportsmen (7).

When groups were compared, it was seen that lactate levels increased following exercise in 3 groups (p<0.05). The levels of 1st and 2nd group significantly decreased with the support (Table I). This finding is parallel to the findings of other researchers (1, 11, 13, 24, 27). Blood lactic acid level reaches the highest level in the 5th minute during intense exercise. It is possible that to duration of exercise between 40 minutes and 1 hour. Pulse rate is between 150/170 beats/min. Lactate concentration either decreases slightly or it remains unchanged in exercises with VO2 max intensity lower than 40%.

However, the lactate concentration starts change in muscle and blood when the intensity increases.

In a study, it has been reported that there was an about 13–16% increase just after exercise in the blood magnesium levels of 12 sportsmen doing exercise in bicycle every day for 1 week, but the other day, these levels were lower than their levels before exercise (6). In some studies it has been observed that there were decreases in magnesium levels depending on the exercise type (4, 10). Liu (16) reported that the magnesium levels of a 24-year-old woman tennis player having daily trainings for 2–3 hours, decreased after exercise. However, in another research it was determined that a 6 week bicycle exercise did not cause any significant change in Mg levels (8). In another research performed with professional volleyball players, mineral levels were found higher than in sedentary peaple 3-months later (20). In our study, sedentary and sportsmen, it was determined that exercise until exhaustion after 4 weeks magnesium supplement increases magnesium levels of groups taking only magnesium supplement, and there were no change, not even unsignificant decreases in the only training group without support for 4 weeks before the exhaustion period. In comparison of the groups, it is seen that the highest levels are in the 2nd and 3rd group respectively which make

Acta Physiologica Hungarica 93, 2006

Lactate and magnesium supplementation

143

us think that there is magnesium loss especially at the end of exercise. Thus, studies have reported that magnesium loss increases either by sweating (4) or by urine (21, 30) which is in accordance with our study.

According to the data obtained at the end of our study, it is shown that a 10 mg/kg/day magnesium support during 4 weeks causes a significant decrease in the lactate levels of Tae-Kwan-do sportmen. It may have an effect on physical performance by delaying exhaustion.

REFERENCES 1. Alaimo K: Dietary of vitamins, minerals, and fiber of persons ages 2 months in The United States: Third National Health and Nutrition Examination Survey 1, 1988–1991 (1994) 2. Berth LV, Alphonse G: The metallobiochemistry of zinc enzymes. Adz. Enzmol. 56, 283–430 (1984) 3. Bohl CH, Volpe SL: Magnesium and exercise. Crit. Rev. Food Sci. Nutr. 42, 533–563 (2002) 4. Brotherhood JR: Nutrition and sports performance. Sports Med. 1, 350–389 (1984) 5. Clarkson PM, Haymes EM: Trace mineral requirements for athletes. Int. J. Sport. Nutr. 4, 104–119 (1994) 6. Cordova A, Alvarez-Mon M: Serum magnesium and immune parameters after maximal exercise in sportsmen. Magnesium Bulletin 18, 66–70 (1996) 7. de Haan A, van Doorn JE, Westra HG: Effects of potassium + magnesium aspartate on muscle metabolism and force development during short intensive static exercise. Int. J. Sports Med. 2, 44–49 (1985) 8. Dressendorfer RH, Petersen SR, Lovshin SE, Keen CL: Mineral metabolism in male cyclists during highintensity endurance training. Int. J. Sport Nutr. Exerc. Metab. 12, 63–72 (2002) 9. Finstad EW, Newhouse IJ, Lukaski HC, Mcauliffe JE, Stewart CR: The effect of magnesium supplementation on exercise performance. Med. Sci. Sports Exer. 33, 493–498 (2001) 10. Golf SW, Bender S, Gruttner J: On the significance of magnesium in extreme physical stress. Cardiovasc.

Drugs Ther. 12, 197–202 (1998) 11. Haralambie G, Senser L: Metabolic changes in man during long-distance swimming. Eur. J. Appl.

Physiol. Occup. Physiol. 43, 115–125 (1980) 12. Kılıç M: Effect of zinc supplementation on physical performance, lactic acide and haematogical parameters in sportmen. PhD thesis, Gazi University, Ankara (2003) 13. Kunstlinger U, Ludwig HG, Stegemann J: Metabolic changes during volleyball matches. Int. J. Sports Med. 8, 315–322 (1987) 14. Laires MJ, Alves F: Changes in plasma, erythrocyte and urinary magnesium with prolonged swimming exercise. Magnesium Res. 4, 119–122 (1991) 15. Laires MJ, Rayssiguier Y, Guezennec CY, Alves F, Halpern MJ: Effect of magnesium deficiency on exercise capacity in rats. Magnesium Res. 2, 136 (1989) 16. Liu L: Hypomagnesemia in a tennis player. Physician Sports Medicine 11, 79–80 (1983) 17. Lowney P, Stern JS, Gershwin ME, Keen CL: Magnesium deficiency and blood 2,3-diphosphoglycerate concentrations in sedentary and exercised male Osborne-Mendel rats. Metabolism 39, 837–841 (1990) 18. Lukaski HC: Micronutritiens (magnesium, zinc and cupper): Are mineral suplements needed for athletes?

Sport Nutrition 74–83 (1995) 19. Lukaski HC, Bolonchuk WW, Kelvay L, Milne DB, Sandstead HH: Maximal oxygen consumption as related to magnesium, copper and zinc nutriture. Am. J. Clin Nutr. 37, 407–415 (1983) 20. Marella M, Guerrini F, Solero PL, Tregnaghi PL, Schena F, Velo GP: Blood copper and zinc changes in runners after a marathon. J. Trace Elem. Electrolytes Health Dis. 7, 248–250 (1993) 21. Mooren FC, Golf SW, Lechtermann A, Volker K: Alterations of ionized Mg2+ in human blood after exercise. Life Sci. 77, 1211–1225 (2005)

Acta Physiologica Hungarica 93, 2006

144

V Çınar et al.

22. Newhouse IJ, Finstad EW: The effects of magnesium supplementation on exercise performance. Clin. J. Sport Med. 10, 195–200 (2000) 23. Rayssiguier Y, Guezennec CY, Durlach J: New Experimental and clinical data on the relationship between magnesium and sport. Magnes. Res. 3, 93–102 (1990) 24. Ripari P, Pieralisi G, Giamberardino MA, Resina, Vecchiet L: Effects of magnesium pidolate on some cardiorespiratory submaximal effort parameters. Magnes. Res. 2, 70 (1989) 25. Rose LL, Carroll DR, Lowe SL, Peterson EW, Cooper KH: Serum electrolyte changes after a marathon running. J. Appl. Physiol. 29, 449–451 (1970) 26. Rude RK, Ryzen E: Tm Mg and renal Mg threshold in normal man in certain pathophysiologic condition.

Magnesium 5, 273–281 (1986) 27. Szot W, Lang-Mlynarska D, Wojtowicz B, Potocki A: Effect of physical training on growth and total cardiovascular and respiratory capacity in pupils from schools with different physical training programs.

Przegl. Lek. 60, 76–80 (2003) 28. Yaman M, Co kunturk OS: Sportif erformansın Sınırları, Ankara (1992) 29. Zorba E: Fiziksel uygunluk. Gazi Kitapevi, p: 245, Ankara (2001) 30. Zorbas YG, Kakurin VJ, Afonin VB, Charapakhin KP, Denogradov D: Magnesium supplements’ effect on magnesium balance in athletes during prolonged restriction of muscular activity. Kidney Blood Pres.

Res. 22, 146–153 (1999)

Acta Physiologica Hungarica 93, 2006