Endurance athletes who use creatine recover faster from their training efforts. Sports scientists at the Graduate Institute of Nutritional Sciences and Education in Taiwan found this out. Creatine supplementation reduces damage caused by endurance exertion to muscle fibres, write the Taiwanese in an article that will soon be published in the European Journal of Nutrition.
It’s not the first time that this web magazine has hammered out the message that creatine [structural formula shown above] may well be an interesting supplement for endurance athletes. When combined with glycerol creatine boosts hydration levels, and that can help endurance athletes who have to perform at high temperatures. When combined with beta-alanine creatine improves endurance capacity. Creatine enables muscle cells to absorb more glucose. To name but a few ideas.
One problem is that athletes may put on weight as a result of taking creatine, but keeping to low doses usually helps.
Nevertheless, not an awful lot is known about the effect of creatine on the metabolism of endurance athletes, so the Taiwanese carried out an experiment with 12 well-trained male students. The students took 12 g creatine every day for 15 days and ran before and just after the supplementation period for 60 minutes at 65-70 percent of their maximal heart rate.
The researchers then repeated the procedure on another occasion, but gave the students a placebo.
Before, during and after the session the researchers analysed the students’ urine and blood. This is how the Taiwanese discovered that creatine supplementation kept the concentration of 3-methylhistidine [3MH] and urea nitrogen [UUN] low. 3-Methylhistidine and urea are indicators of muscle breakdown.
If the body burns protein the concentration of ammonia in the blood rises. The body neutralises this through a reaction in which glutamate is converted into glutamine. Because the researchers found less glutamine in the athletes, they suspect that creatine supplementation helps the muscles of endurance athletes to burn less protein during exercise.
“In terms of metabolism, creatine supplementation possessed the advantages of decreasing muscle glycogen and protein degradation, especially after endurance exercise, although it might not benefit the endurance performance”, the researchers conclude.
The study was not financed by supplements manufacturers but by National Taiwan Normal University.
Contribution of creatine to protein homeostasis in athletes after endurance and sprint running.
Tang FC, Chan CC, Kuo PL.
Source
Graduate Institute of Nutritional Sciences and Education, #162, Hoping E. Rd. 1st Sec, Taipei, 10600, Taiwan, ROC, t10013@ntnu.edu.tw.
Abstract
PURPOSE:
Few studies have focused on the metabolic changes induced by creatine supplementation. This study investigated the effects of creatine supplementation on plasma and urinary metabolite changes of athletes after endurance and sprint running.
METHODS:
Twelve male athletes (20.3 ± 1.4 y) performed two identical (65-70 % maximum heart rate reserved) 60 min running exercises (endurance trial) before and after creatine supplementation (12 g creatine monohydrate/day for 15 days), followed by a 5-day washout period. Subsequently, they performed two identical 100 m sprint running exercises (power trial) before and after 15 days of creatine supplementation in accordance with the supplementary protocol of the endurance trial. Body composition measurements were performed during the entire study. Plasma samples were examined for the concentrations of glucose, lactate, branched-chain amino acids (BCAAs), free-tryptophan (f-TRP), glutamine, alanine, hypoxanthine, and uric acid. Urinary samples were examined for the concentrations of hydroxyproline, 3-methylhistidine, urea nitrogen, and creatinine.
RESULTS:
Creatine supplementation significantly increased body weights of the athletes of endurance trial. Plasma lactate concentration and ratio of f-TRP/BCAAs after recovery from endurance running were significantly decreased with creatine supplementation. Plasma purine metabolites (the sum of hypoxanthine and uric acid), glutamine, urinary 3-methylhistidine, and urea nitrogen concentrations tended to decrease before running in trials with creatine supplements. After running, urinary hydroxyproline concentration significantly increased in the power trial with creatine supplements.
CONCLUSIONS:
The findings suggest that creatine supplementation tended to decrease muscle glycogen and protein degradation, especially after endurance exercise. However, creatine supplementation might induce collagen proteolysis in athletes after sprint running.
PMID: 23392621 [PubMed – as supplied by publisher]
