Creatine and Rowing
As with many topics I turn to the American College of Sports Medicine for information today about Creatine supplementation. I then look at a few studies involving rowers specifically that you might easily come across.
A number of young athletes have taken to using creatine supplements in the hopes of building muscle and enhancing performance. The numbers are growing, and increasingly they are being taken by junior athletes under the age of 18. What should an individual do? What should a coach say when approached by an athlete or parent?
A round table discussion paper that reviews the literature on Creatine is used for this posting. It is available at this link:
The physiological and health effects of oral creatine supplementation
PCr (phosphocreatine) is the immediate energy source used to resynthesize ATP in the muscles. ATP is the immediate energy store used by contracting muscles. It is an important energy store for short-term (3-6 seconds) high intensity exercise as in the rowing start, or a sprint at the end of a race. It is important for all exercise well above VO2 max and in the initial transition from rest to exercise, or while quickly elevating power. This system's importance continues as it provides up to 25% of energy used in a 30s sprint. It becomes less significant as duration of exercise extends and intensity decreases is a direct result of muscles' small stores of PCr.
Creatine Absorption and Supplementation
Creatine is synthesized within the body from amino acids (from protein). There is some evidence that muscle Cr content is lower in vegetarians.
There does appear to be an initial period of about three days where excess Cr is absorbed in the muscles - increasing PCr content up to 20%. After the capacity of the muscle to extract Cr from the blood is exceeded the rest is exceted in the urine. "…continued ingestion of large doses of Cr simply establishes Cr-enriched urine."
There is a wide range of increase in Cr seen from supplementation from 0% non-responders to 40% but the uptake appears to be inversely related to previous stores. i.e. muscles that had little will take on more - but there appears to be an upper limit for Cr stores in the muscle.
As after about 2 days there is spillover into the urine, there seems little need to extend supplementation. beyond this point.
Most studies used a "loading dose" of 20 g per day - spread out over 4-5 doses in the day, then single 2 g per day dose to maintain stores after a varying period of loading from 3-5 days.
Although commercially available with several different dietary additives claimed to augment the effects, there does not appear to be any evidence that it will help.
With increased Cr stores there is muscle enlargement "due to water absorption" and a resulting rapid increase in mass of 1-3 kg after only 4-7 days of supplementing.
There is no evidence of an anabolic effect (muscle growth) from supplementation.
It is suggested that even a 20% increase in PCr from supplementing may not provide detectable performance gains - but in repeated bouts of exercise where resynthesis of PCr is needed, it may well help in subsequent bouts of exercise.
There is no evidence of an increase of muscle aerobic power.
Most, but not all, studies do show an improvement in performance from supplementation, but generally these in the later bouts of a repeated series of high intensity exercises.
It does not seem to increase maximal strength or the rate of force production - but may increase 1 rep dynamic strength - tested with 3-6 progressive contractions to establish a maximum - could this mean it would help in rowing starts?
It did have a positive 30% improvement in anaerobic power production during short sprints within and at the end of endurance events.
May enhance normal adaptations to weight training - perhaps due to ability to perform greater volume of lifting, likely related to the help with repeated bouts of exercise.
There are anecdotal reports of some negative effects - nausea, diarrhea etc.
Also reports of cramping, strains and stiffness.
Some evidence anecdotally of hypertension (higher blood pressure) in athletes supplementing.
Some evidence that there may be altered fluid balance with chronic supplementation…therefore: "our present recommendation for individuals wishing to control weight and who are subjected to strenuous exercise and/or hot environments is to avoid Cr supplementation. Further, high-dose Cr supplementation (i.e., 20 g per day) should be avoided during periods of increased thermal stress, such as sports activities performed under high ambient temperature/humidity conditions."
There is almost no evidence examining the effect in children less than 18 years of age.
Lightweights take note:
Wrestlers trying to lose 5% of body mass in 5 days (make weight) lost less while supplementing on Cr due to fluid retention.
ACSM Recommendation on Safety:
The fact that Cr is a naturally occurring compound does not make supplementation safe, as numerous compounds are good, even essential in moderation, but detrimental in excess. Further, the lack of adverse effects does not equal safety, since unending research must be performed to eliminate the possibility of all theoretical complications.
Studies involving Rowing
There have been a number of studies involving rowers, that are freely available. Three are listed here as examples:
1. The effect of oral creatine supplementation on the 1000-m performance of competitive rowers.
This was a properly controlled study, published in a "peer-reviewed" scientific journal, as such we can trust that it was a well conducted study.
The study found that competitive rowers following creatine loading saw an average improvement of 2.3 s in 1000 m erg time - though this was not considered statistically significant, probably because there was a large variation in results compared to the number of people in the study.
2. Effect of creatine supplementation on aerobic performance and anaerobic capacity in elite rowers in the course of endurance training.
This study was posted on the web site of a company selling creatine. As such its results should be considered highly suspect. One has to ask - if it were a solid study why is it not in a peer-reviewed journal?
16 elite male rowers (Polish) were studied.
They found no improvement in maximal power output.
Mean wattage at lactate threshold improved by some 24 Watts. This is big as it suggests a large increase in the power that could be sustained for a long period of time.
There was an increase in time to exhaustion of 12 s. in an anaerobic capacity test.
3. The Effect Of Creatine Monohydrate Supplementation During Combined Strength And High Intensity Training On Performance In Rowers
- This study was also just posted on the web, not in a journal.
- No effects seen doing repeated intervals or a 2000 m erg test.
- There is some evidence of improved short-term athletic performance.
- There is evidence of increased muscle growth, probably because it improves the volume of training that can be handled in the weight room.
- There is evidence of weight gain from water retention.
- There is no conclusive evidence that this would translate to rowing, although there are aspect of the race that mimic the types of exercise seen to be improved by Cr.
- There are reports of complications - under no circumstances should anyone try it for the first time leading up to an important competition.
- Sustained periods of high doses will only lead to you producing expensive urine!
- It should not be used when competing or training in high temperature environments.
- Lightweights may have problems with fluid retention when trying to make weight.
Given the potential problems, and the relatively minor benefits is it really worth it?