- Humans live their life almost 24/7 in motion . For us to be capable to do that,the main thing is to provide muscles with energy. Our muscles use specific kind of energy which is stored in organic molecules. The main energy molecule which is used in muscles is ATP. One of best energy storage in our body is phosphocreatine.It is necessary for generating of ATP.
Things you should know about creatine and the way it works
- Creatine is organic molecule which is produced in our body. But it is also found in food we ingest. In our body is roughly the same proportion of creatine ingested through food and creatine synthesized in the body. Creatine is transported via the blood to the muscles, where it is stored for future use. 1Our muscles can not use creatine by itself for generating energy. But one of the main characteristic of creatine is its ability to bind phosphorus and create phosphocreatine. In that form creatine is used in our muscles. The phosphorus in phosphocreatine molecule can be transfered to ADP creating on that way ATP and creatine. This is the way that muscles use phosphocreatine to produce the energy required for muscle contraction.2
Things you should know about structure of the muscles
- Muscles are part of the body that are responsible for moving. There are three kinds of muscle tissue in our body: skeletal, smooth and cardiac. Skeletal muscles are part of musculoskeletal system, together with the bones, joints, cartilage, ligaments, tendons and other connective tissues .3 Every skeletal muscle has its origin and insertion. Part of muscle between origin and insertion is called muscle belly. It consists of muscle fibers. There are three types of fibers in skeletal muscle: type I – slow twich fibers, IIa – fast oxidative fibres and IIb – fast glycolytic fibers. Every muscle is made of different ammount of these three types of fibers. That depends on the function that muscle has.Under the microscope in every muscle fiber are cytoplasmic proteins, actin and myosin. They are responsible for contracting. At origin and insertion muscles are attached to bones by tendons.3
- Skeletal muscles are in most cases superfitial structures, located under skin and fat tissue. Therefore they are susceptible to injuries. There are different types of muscle injury:
Bruises – contusions
- They are very common injury, especially in contact sports. They are caused by direct blow to the muscle. If blow is strong enough it can cause tear of some muscle fibers. Bruised muscle is swollen, pain at rest, often visible hematoma on place of blow. 4
Strain – pulled muscle
- Strain occurs when a muscle is stretched over its limit. In that case some muscle fibers remain streched. Muscle is swollen, movement causes pain, partial loss of muscle function, cramps4
- There are two types of rupture – partial and complete. In partial rupture only some of muscle fibers are torn. In complete rupture all muscle fibers are torn. Muscle loses its function,it is swollen, pain at rest, often there is big bruise 4
Muscle injury markers
- After muscle injury, serum levels of some skeletal muscle enzymes and proteins may rise or fall. The most important ones are creatine kinase (CK), lactate dehydrogenase (LDH), aldolase, myoglobin, troponin, aspartate aminotransferase (AST) and carbonic anhydrase CAIII.5 They are important because they can be used to evaluate extensiveness of muscle injury.
How does muscle heal
- After every injury it takes time for muscle to heal. In almost every muscle injury treatment is the same.
- RICE – Rest,Ice,Compression, Elevation is the basic principle. In severe cases like complete muscle rupture operative treatment is an option. 4
- It it important to know that muscle always heals weaker than it was. Unlike bone,which always heals stronger. After every injury hematoma is formed because of bleeding from damaged muscle fibers and blood vessels. In hematoma are different blood cells and chemicals which cause muscle to heal by forming scar. That scar is never formed of new muscle cells. It always consists of weaker tissue whose main substance is collagen. 4 That scars are weak points for future injurie .
How muscle contracts
- Main function of skeletal muscles is moving of different body parts. It is done by muscle contraction. As mentioned above, for contraction muscle needs ATP. No ATP = no contraction = no movement. Therefore it is of utmost importance that the muscles have a sufficient amount of ATP to contract. It can be done by storing phosphocreatine. Somewhere around 95 % of creatine in body is stored in skeletal muscles. 1
- As long as there is a sufficient amount of ATP in muscle, it can contract.Then it is logical that if you have a larger amount of creatine stored in muscle you will have a longer and stronger muscle contraction. It was well known fact in scientific circles. But only in the early 90’s creatine suplements have appeared on the world market. Athletes have embraced that, so they started using creatine suplements to improve their performance.
Recent findings related to prevention of muscle damage
- Lately, scientists have shown interest in the possibility of using creatine to prevent muscle injuries.A number of studies have been published.
- In one study researchers were comparing serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), aldolase (ALD), glutamic oxaloacetic acid transaminase (GOT), glutamic pyruvic acid transaminase (GPT), and C-reactive protein (CRP) in two groups of Ironman triathletes before and after the competition. Serum levels of all markers were higher in placebo group. Creatine supplementation group had lower levels of markers. Thei results were the same in tested rats. Their conclusion is that creatine supplementation can prevent muscle injury induced by strenuous contractile activities.6
- Other group of researchers found that creatine supplementation inhibited the increase of inflammation markers TNF-α and CRP. 25 players were randomly assigned to two groups: placebo and creatine suplement. Double-blind controlled supplementation was performed. Serum levels of markers were taken before exercise, just after and one hour after completion. Their results show TNF-α and CRP were increased in placebo group. Creatine supplementation reduced the increase in serum markers. 7
- On the other hand there are studies that show different results. One of them suggest that creatine supplementation does not reduce skeletal muscle damage. In that study twenty-two healthy, weight-trained men ingested either creatine or a placebo for 10 days. On day 5, subjests performed exercise test. Creatine kinase (CK), LDH, CRP were measured before exercise and during a 5-day follow up. Serum markers for creatine and placebo-supplemented subjects showed almost the same results. 8
- The results from studies mentioned above show that there is still no definite stance on the benefits of using creatine for preventing muscle damage. There will be a need for additional research to confirm or disprove the thesis.
- Creatine . MedLine Plus Supplements. U.S. National Library of Medicine. 20 July 2010. Retrieved 2010-08-16.
- Tero AH Järvinen, Markku Järvinen, and Hannu Kalimo. Regeneration of injured skeletal muscle after the injury. Muscles Ligaments Tendons J. 2013 Oct-Dec; 3(4): 337–345.
- Brancaccio P, Lippi G, Maffulli N. Biochemical markers of muscular damage. Clin Chem Lab Med. 2010 Jun;48(6):757-67
- Bassit RA, Pinheiro CH, Vitzel KF, Sproesser AJ, Silveira LR, Curi R. Effect of short-term creatine supplementation on markers of skeletal muscle damage after strenuous contractile activity. Eur J Appl Physiol. 2010 Mar;108(5):945-55
- Deminice R, Rosa FT, Franco GS, Jordao AA, de Freitas EC. Effects of creatine supplementation on oxidative stress and inflammatory markers after repeated-sprint exercise in humans. Nutrition. 2013 Sep;29(9):1127-32.
- Rawson ES, Conti MP, Miles MP. Creatine supplementation does not reduce muscle damage or enhance recovery from resistance exercise. J Strength Cond Res. 2007 Nov;21(4):1208-13.