Kreatin – afkorter genoptræningsperioden

En ny undersøgelse offentliggjort i det videnskabelige tidsskrift Journal of Physiology viser at patienter med knoglebrud og idrætsskader kan blive genoptrænet hurtigere ved anvendelsen af kreatin.
Bag undersøgelsen står Center for Muskelforsknings afdeling på Institut for Idræt ved Københavns Universitet.

Hvis du mangler kreatin kan du købe billigt kreatin her.

Forsøget

20 raske unge fik lagt det ene ben i gips i to uger og deltog derefter i 10 ugers genoptræning. Undervejs fik halvdelen et kreatin-tilskud, mens den anden gruppe fik et uvirksomt middel. Under genoptræningen voksede muskelmassen og muskelstyrken ca. 40 procent mere blandt deltagere på kreatintilskud end blandt de øvrige.

»Det bør få den konsekvens, at man undersøger virkningen på folk, som reelt er kommet til skade - opereret for en korsbåndsskade eller har brækket et ben. Jeg vil blive forbløffet, hvis effekten ikke er den samme som på vores forsøgspersoner, men inden man går ud og siger til alle, at de skal bruge kreatin i genoptræningen, bør man undersøge det på patienter først,« siger professor, Erik A. Richter, Center for Muskelforskning.

Hespel, P., Eijnde, B.O., Leemputte, M.V., Urso, B., Greenhaff, P.L., Labarque V., Dymarkowski, S., Hecke, P.V. and Richter, E.A. (October 2001) Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. Journal of Physiology Volume 536: 2: pages 625-633.

Engelsk version med yderligere forklaringer
Creatine and recovery from injury.

Background

Mature skeletal muscle is produced from the union of progenitor cells known as myoblasts. These myoblasts lie dormant waiting for the appropriate environmental cue to stimulate them to fuse. One of the most potent of such environmental cues is the loss of muscle tissue arising from inactivity or disease. To summarize, lost or damaged muscle is replaced by new muscle formed from the fusion of thousands of myoblasts.

The loss of muscle tissue because of inactivity or disease is known clinically as disuse atrophy. Anyone who has had a broken limb can testify to this effect. After weeks in a cast the immobilized limb is noticeably smaller and weaker than its unrestrained counterpart. In this instance inactivity resulted in muscle tissue actually being reabsorbed by the body. When the limb again becomes active the body replaces this lost muscle tissue through a process known as myogenesis.

Myogenic factors

Although muscle loss induces the process of regeneration, the actual triggering signal is a biochemical messenger. These biochemical messengers, also known as myogenic factors, were the focus of a recent study involving creatine.

The Study

This study examined the effect of creatine supplementation on the recuperation of muscle function following leg immobilization. Twenty-two college-aged subjects participated in the study. All subjects had their right leg immobilized in a cast for a period of two weeks. Ten weeks of rehabilitation therapy followed the two weeks of cast immobilization.

Throughout the entire study half of the subjects took creatine while the other half took placebo (maltodextrin). During the two weeks of immobilization the subjects supplemented their daily diets with 20 grams of either creatine monohydrate or placebo. During the rehabilitation period the creatine/placebo dose was reduced. For the initial three weeks of rehabilitation the subjects consumed 15 grams of creatine/placebo per day. Thereafter, the creatine dose was reduced to only 5 grams of creatine/placebo for the remaining seven weeks of rehabilitation.

Cross-sectional area of the quadriceps muscle (upper leg), leg extension power and myogenic factor expression were compared in the two groups.

Results

This study demonstrated that leg cross-sectional area and strength recovered more rapidly in those individuals who had supplemented with creatine.

Most importantly, myogenic factor expression was greater for the creatine group during the rehabilitation phase of the study. In particular, one myogenic factor, MRF4 (Myogenic Regulatory Factor 4), correlated strongly with the increase in leg cross-sectional. It would thus appear that MRF4 is responsible for the muscle regeneration observed in this study. Interestingly, MRF4 exerts its greatest effect over those muscle fibers most sensitive to creatine supplementation; the fast muscle fibers.

Conclusions

This study concluded that creatine supplementation stimulates muscle growth and recovery through the production of myogenic factors, in particular one known as MRF4. The authors of the study openly state that "creatine supplementation is capable of shortening the duration of rehabilitation needed to restore muscle mass following an episode of disuse atrophy".

Take Home

This study suggests that creatine increases the expression of myogenic factors that induce muscles growth.

Scientific references

Hespel, P., Eijnde, B.O., Leemputte, M.V., Urso, B., Greenhaff, P.L., Labarque V., Dymarkowski, S., Hecke, P.V. and Richter, E.A. (October 2001) Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. Journal of Physiology Volume 536: 2: pages 625-633.

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