Creatine Supplementation Enhances Muscular Performance During High-Intensity Resistance Exercise Volek

Essays

Creatine Supplementation Enhances Muscular Performance During High-Intensity Resistance Exercise Volek

The main purpose of this research was to determine if creatine supplementation has any positive effect on high-intensity resistance exercise. The investigation involved two groups of seven, a placebo group and a creatine group. The subjects underwent a bench press protocol and a jump squat protocol every fifth and sixth day of an 18 day experiment. Both groups of subjects received no supplementation before T1 (day 6) and a placebo from T1-T2 (days 7-12). From T2-T3 (days 13-18), only the creatine group received a daily dosage of 25 grams of creatine monohydrate.

The first day of testing involved the subjects performing a bench press protocol consisting of five sets of repetitions with weight equal to their 10 repetition maximum, which was determine pre-investigation. On the second day, the jump squat protocol involved the subjects performing five sets of ten repetitions with resistance equal to 30% of their one repetition maximum.

During T1-T2, the placebo group experienced increased performance during sets two, four, and five of the bench press protocol while the creatine group showed an increase during set two. During T1-T2, the placebo group showed increased power output during set two of the jump squat while the creatine group showed an increase during set five. From T2-T3, only the creatine group showed elevated performance in all five sets of each protocol. These results allowed the authors to conclude that one week of creatine supplementation increases muscular performance during high-intensity resistance exercise.

Effect of Oral Creatine Supplementation on Skeletal Muscle Phosphocreatine Resynthesis Greenhaff

The purpose of this investigation was to determine the effect of creatine supplementation on phosphocreatine resynthesis within skeletal muscle. The study consisted of eight male subjects and the study lasted a period of ten days. On the first day of the experiment, each subject had their phosphocreatine stores depleted by means of an isometric stimulation protocol directed at skeletal muscle within their legs. Biopsy samples were acquired at recovery times 0, 20, 60, and 120 seconds after stimulation from the vastus lateralis muscle.

This same protocol was performed ten days later on the opposite leg, the only difference being that the subjects ingested 20 grams of creatine for the five days prior. These new biopsies allowed for comparison of new values for muscle ATP, phosphocreatine, free creatine, and lactate concentration with those obtained from the day one biopsies.

The investigation resulted in five of the eight test subjects having a significant increase of total creatine concentration within the muscle after creatine supplementation.