Friday 13 February 2009

Creatine supplementation - implications for the competitive weightlifter - Eamonn Flanagan


Here is a guest article by Eamonn Flanagan. He is an excellent lifter himself and his credentials have lots of letters after his name, so you know he must be good!
Below is a summary of his article which was published in the NSCA journal. Here is a link to the full article with references in tow if you wish to read it. He generously condensed it for this blog, so thank you Eamonn.



Eamonn Flanagan, Ph.D., CSCS*D

Creatine is a massively popular nutritional supplement. All muscle contractions are fueled by energy. The first energy source called upon is termed ATP. However, as free ATP stores are very limited they have to be regenerated by other metabolic processes in order to generate and sustain high muscle power output. The secondary source of immediate
energy is phosphocreatine. ATP, augmented by the phosphocreatine energy pathway sustains maximal effort muscular contraction for between 5 to 15 seconds. Approximately 95% of the body's creatine pool is present in skeletal muscle. Creatine supplementation, by the oral administration of the supplement "creatine monohydrate", has been shown to increase the muscular pool of creatine.

This increase in muscle creatine stores enhance work output in the latter stages of exercise which is dependent on the phosphocreatine energy pathway. Such exercise is short duration (1–30 seconds), intermittent, high intensity exercise (2, 3, 22). Fatigue, in this type of high intensity exercise is reduced by creatine supplementation. With more creatine available in the muscles, ATP can be regenerated through the phosphocreatine pathway at a more efficient rate. This leads to a greater energy provision in the latter stages of high intensitty, intermittant exercise. Weightlifting is a prime example of one such activity which can benefit from creatine supplementation.

Both anecdotally and in the published peer-reviewed research, a most popular and effective method of supplementation is to acutely load creatine over a short duration of between 5 and 7 days. This has commonly been achieved by administering 20–25 g/day of creatine monohydrate, divided into 4–5 doses of 5g each, over 5–7 days. Such protocols have
been shown to significantly increase individuals' muscle creatine content and to improve performance in high intensity, intermittent exercise.

In the published research, the only documented side effect of creatine supplementation is an increase in body mass caused by increased water retention within the muscle. There
have been many anecdotal claims that creatine users are more likely to suffer from heat-related cramping and renal dysfunction. However, empirical evidence does not support these claims and has shown that creatine supplementation over prolonged periods, within recommended dosages, is a safe practice.

For weightlifters who may be in the very light weight classes or who maybe well into the superheavyweight class a supplementation protocol standardized to body mass could be followed. The loading dosage can be individualized by supplementing with 0.3 g of creatine monohydrate for each kilogram of the athlete's body weight, per day. This amount can be divided into 4-5 equal doses, each day, for 5 to 7 days. A hypothetical female lifter in the lightest weight class (48 kg) weighing 47 kg would take approximately 14g of creatine monohydrate (47 × 0.3 g) each day in 4 doses of 3.5 g for the duration of the loading period. A hypothetical heavyweight male lifter in the heaviest weight class (105kg) weighing 110 kg would take approximately 33 g of creatine (110 × 0.3 g) each day in 4 doses of approximately 8.25g.

Following the 5-7 day loading protocol, research suggests athletes can maintain their elevated muscular creatine stores with a single daily dose ranging from 1 to 3g (for light to heavy individuals. 5g maintainence dosages are also not uncommon and have been shown to have no adverse affect on renal function and general health.

Weightlifters and their coaches should be aware of how exactly creatine supplementation can be expected to change their performance. Creatine supplementation improves the rate at which energy can be provided during fatiguing exercise but does not the improve the maximum amount of energy that can be provided in the non-fatigued state. For this reason supplementation will not increase the maximal muscular contraction velocity or the peak power production of muscle in the non-fatigued state. Weightlifters should be
aware that supplementation will not suddenly, directly increase their maximum in the snatch or clean and jerk.

However, supplementation will delay fatigue, facilitate recovery, and increase power output in the later stages of training. This will allow the weightlifter to perform a greater workload in each training session, which over time will assist in increasing performance in maximum effort lifts. Consiering the physiology, creatine supplementation is of particular benefit during high-intensity, fatigue-inducing, and high-volume training phases. In weightlifting, the preparation phase, where number of reps per set are higher, total volume is higher, recovery time between sets is lower and number of assistance lifts are higher is an example of this. In a competition phase, where average intensity is elevated but total volume is decreased, where few assistance lifts are performed and where many single effort lifts with long recovery periods are performed the supplement would be much less beneficial.

Another factor that may influence the timing of creatine supplementation within the training cycle is the rapid weight gain associated with loading. Creatine is an osmotically active substance; meaning as creatine is drawn into the muscle cells water is drawn in
with it. This water retention has been associated with acute changes in body mass ranging from 1 to 3 kg following creatine loading phases. Weightlifting is a weight-controlled sport in which many competitors commonly "make weight" prior to competition. Weightlifters bound to maintaining strict body weights prior to competition should exercise caution when introducing a supplement that can induce such a sudden increase in weight.

Weightlifters may not wish to introduce the supplement for the first time in the competition phase of preparation as the associated weight gain may elevate them out of their preferred weight classification for competition. Weightlifters should introduce the supplement early in the training cycle, in the preparation phase, so they are afforded ample opportunity to counterbalance any additional
weight gain caused by supplementation with calorie reduction or other preferred making weight practices prior to competition
weigh-in. Muscle creatine levels which are elevated due to supplementation will return to resting levels after 25-35 days of no supplementation. Lifters can therefore cease supplementation about 1 month before an important competition for which they must make weight. This could reesult in 1-3kg of weight being lost by the lifter without appreciable changes in maximal strength. The lifters fatigue resistance will be reduced but with a proper competition phase (of high intensity and lower volume with longer recovery periods between reps) and a tapering phase (reduced volume prior to competition) this should not be a deleterious effect.

PRACTICAL APPLICATIONS SUMMARY:

- Weightlifters who wish to introduce a creatine supplement into their nutritional program are advised to choose creatine monohydrate as to date it is the only creatine product that has been extensively researched by the sports and exercise science community and shown to be a legitimate performance enhancer.

- Creatine monohydrate can be hugely beneficial for weightlifters particularly during high volume phases of training that are
characterized by high repetitions and are significantly fatiguing.

- Weightlifters attempting to maintain a specific body weight for competition should introduce the supplement early in the training
cycle, in the preparation phase, so that they are afforded ample opportunity to counteract any additional weight gain caused by supplementation. Creatine supplementation can be withdrawn about 1 month before competition if additional bodyweight needs to be lost.

- Particularly heavy or light weightlifters may wish to implement a creatine loading phase that is individualized to their own body weight.


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Eamonn Flanagan, Ph.D., CSCS*D

1 comments:

Shane said...

Alrite Barry, I've been reading away at your blog over the last few weeks, tis great stuff, keep it up.

Found this article very interesting, I've never tried monohydrate myself because I was wary of the weight gains. Might be something to try in the future.

Hopefully I'll be back to Hercs soon. Miss that place!

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