Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women
Issue Date
2007Author
Smith, Abbie E.
Herda, Ashley A.
Herda, Trent J.
Ryan, Eric D.
Moon, Jordan R.
Cramer, Joel T.
Stout, Jeffrey R.
Publisher
BioMed Central
Type
Article
Article Version
Scholarly/refereed, publisher version
Published Version
http://www.jissn.com/content/4/1/20Metadata
Show full item recordAbstract
The purpose of this study was to examine the effects of 5 days of Creatine (Cr) loading on the
electromyographic fatigue threshold (EMGFT) in college-aged women. Fifteen healthy college-aged
women (mean ± SD = 22.3 ± 1.7 yrs) volunteered to participate in this double-blind, placebocontrolled
study and were randomly placed into either placebo (PL – 10 g of flavored dextrose
powder; n = 8) or creatine (Cr – 5 g di-creatine citrate plus 10 g of flavored dextrose powder; n
= 7; Creatine Edge, FSI Nutrition) loading groups. Each group ingested one packet 4 times per day
(total of 20 g/day) for 5 days. Prior to and following supplementation, each subject performed a
discontinuous incremental cycle ergometer test to determine their EMGFT value, using bipolar
surface electrodes placed on the longitudinal axis of the right vastus lateralis. Subjects completed a
total of four, 60 second work bouts (ranging from 100–350 W). The EMG amplitude was averaged
over 10 second intervals and plotted over the 60 second work bout. The resulting slopes from each
successive work bouts were used to calculate EMGFT. A two-way ANOVA (group [Cr vs. PL] ×
time [pre vs. post]) resulted in a significant (p = 0.031) interaction. Furthermore, a dependent
samples t-test showed a 14.5% ± 3.5% increase in EMGFT from pre- to post-supplementation with
Cr (p = 0.009), but no change for the PL treatment (-2.2 ± 5.8%; p = 0.732). In addition, a significant
increase (1.0 ± 0.34 kg; p = 0.049) in weight (kg) was observed in the Cr group but no change for
PL (-0.2 kg ± 0.2 kg). These findings suggest that 5 days of Cr loading in women may be an effective
strategy for delaying the onset of neuromuscular fatigue during cycle ergometry.
Description
This is the publisher's version, also found at http://www.jissn.com/content/4/1/20
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Citation
Smith, A.E.; Walter, A.A.; Herda, T.J.; et al. (2007) Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women.
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