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Despite the abundance of research that indicates that
creatine supplementation is effective at increasing lean body mass and strength,
there is also a lot of evidence which seem to contradict these claims.
Creatine may not offer fatigue resistance: In their
double-blinded placebo controlled study of 32 individuals using 20 g/d x 1 week
loading followed by 5 g/d for 8 weeks, Stevenson and Dudley found that creatine-supplemented
subjects who were allowed to exercise their quadriceps muscles to their liking while receiving standardized electromyostimulation (EMS) therapy did not
demonstrate significantly greater gains in size of muscle (measured by MRI) or
strength as compared to their placebo-controlled counterparts. They conclude
that creatine supplementation doesn't augment the hypertrophic or mechanical
responses to an accurately measured conditioning stimulus (EMS). They suggest
that enhanced fatigue resistance doesn't explain the the beneficial effects of
creatine supplementation because muscle growth and fatigue resistance were not
augmented in the creatine group.
Creatine may act primarily as a substrate for polypeptide
synthesis: In their study, Tarnopolsky et al. argue that current
creatine research is somewhat inadequate because of a lack of proper controls.
They designed a study in which 23 participants received 10 g creatine and 75 g
glucose, 10 g casein protein and 75 g glucose, or simply glucose for 8 weeks by
double-blinded allocation. They were allowed to follow their own exercise plans.
After the 8-week period, muscle biopsies did confirm that the creatine-supplemented
group had a higher total creatine concentration than the protein-glucose or
control groups. However, the creatine-glucose and protein-glucose groups did
experience similar statistically significant increases in strength in various
exercises as compared to the control group. In addition, the creatine-glucose
and protein-glucose groups also had identical increases in muscle fiber
diameter. The only difference between the two groups was that the creatine-glucose
group had an increase in fat-free mass, which the authors attributed to an
increase in the total body water content. The authors conclude that there were
similar increases in strength and muscle fiber area between the creatine-glucose
and protein-glucose groups.
Creatine may be ineffective in short-term anaerobic
running: An article by Edwards, et al. reports that 21 moderately
active males who received either 20 g/d x 6 days or placebo, which was assigned
in a double-blinded manner, demonstrated that creatine supplementation did not
help to increase performance during an anaerobic speed test, in which they had
to run 8 mph up a 20% grade. |
