Creatine Studies

 

 

Dr. Harris Study

Dr. Harris a few years back conducted a study examining creatine content in the quadriceps femoris muscle in 17 subjects after supplementation of 5 g of creative monohydrate 4-6 times a day for two days.

The results found a significant increase in the total creatine level in all subjects but the results were especially noticeable in those with the lowest muscle creatine store at the start of the study.

These subjects were most often vegetarians. To determine whether exercise could affect the amount of creatine absorbed by muscles, some of the participants followed a unique training program.

During supplementation, they pedaled a bicycle ergometer for one hour each day while using only one leg to supply the pedaling force.

With supplementation, the unexercised legs increased their creatine levels by about 25 percent, but the exercised legs increased their creatine levels by 37 percent.

 It is hypothesized that exercise increases the flow of blood to the muscles or changes the rate at which muscles absorb creative from the blood, thus improving the creatine loading effect.

Dr. Earnest Study

Dr. Earnest conducted a study investigating the influence of creatine monohydrate supplementation on muscular power and strength in 10 experienced weight trained male subjects.

Three series of high intensity, anaerobic type muscular workouts were used.

The first series consisted of three consecutive 30 second Wingate bike tests, followed by five minuets of rest. Peak anaerobic power was defined as the greatest power achieved in a given five second work interval.

Anaerobic work was defined as the total amount of work performed in a 30 second period. The second series used a one repetition maximum (lRM) free weight bench press as a test of muscular strength.

The third series utilized complete lifting repetitions at 70% of the bench press IRM until fatigue. Fatigue was defined as the inability to complete one lifting repetition or the inability to maintain a lifting cadence of one second eccentric and one second concentric (lifting and lowering the weight).

Total lifting volume was calculated as 70% of pre-test IRM multiplied by the number of complete lifting repetitions. Subjects received either a glucose placebo or creatine monohydrate supplement in a double blind fashion. (After 14 days of supplementation, each subject was re-tested on the Wingate bike tests.

Re-testing for the weight lifting trials was done after 28 days of supplementation.

Within the creatine group, total anaerobic work from the Wingate tests was significantly higher during all post-test trials.

The increases were (13%) for series one, 18% for series two and 18% for series three. No changes were noted in the placebo group. Greater total anaerobic work resulted from the creatine subject's ability to achieve and maintain higher levels of anaerobic power consistently over- each five second time interval.

Bench press IRM increased (6% )in the creatine group. Total lifting volume was significantly higher within the creatine group, whether expressed in absolute terms (26%) or relative terms (29%).

Increases in the total lifting volume were associated with the ability of the creatine group to perform (26%) more lifting repetitions.

The authors conclude that the ability of the creatine group to perform a greater total lifting volume demonstrates the effectiveness of creatine as an ergogenic aid.

Hultman's study

In Hultman's study (cited in Anderson, 1974) these results were replicated.

Each day, creatine was given in six separate doses of five grams a day.

 During the six-day period, five other Estonian runners of comparable ability received a glucose placebo instead. All runners were unaware of the actual composition of their supplements.

Before and after the six-day supplementation, the athletes ran four 300-meter and (on a separate day) four 1000-meter intervals, with three minutes of rest between the 300-meter intervals and four minutes of rest between the 1000-meter intervals.

Improvement on the final 300-meter interval (from pre-to-post supplementation) was more than twice as great for creatine users, and improvement was more than three times as great for creatine supplements in the final 1000-meter interval.

Total time to run all four 1000-meter intervals improved from 770 to 757 seconds after creatine supplementation.

 In comparison, the placebo group actually slowed from 774 to 775 seconds.

 

 

creatine - glutamine - creatine ethyl ester - taurine - citruline malate - aakg - ornithine 

 tri creatine malate - beta alanine - saw palmetto - tribulus - acetyl l carnitine