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Unformatted text preview: s Endurance Much of the previous Cr literature has focused on
improvements in anaerobic and intermittent physical activity. In terms of sport performance, there is
less evidence to support the use of Cr with activities
Sports Med 2005; 35 (2) 120 that are longer in duration than 3 minutes. The
potential positive ergogenic effects that Cr might
have on submaximal endurance performance have
been addressed in only a few papers since the year
2000. Jones et al. investigated the effects of Cr
loading on oxygen uptake (VO2) kinetics during
submaximal cycle exercise. Five subjects received
Cr (20 g/day for 5 days followed by 5 g/day maintenance dose) while four subjects served as controls.
Following all testing conditions, 35–50 days later,
the five subjects initially supplemented with Cr now
served as controls and the initial four control subjects were now supplemented with Cr. Paired t-tests
revealed that there were no significant differences
between groups for the VO2 kinetic response during
the moderate exercise protocol and that Cr had no
ergogenic effect. The limitations of this study involve the statistical analyses and the small sample
However, similar results were obtained by Syrotuik et al. when they examined the effect of Cr
supplementation (0.3 g/kg BW/day, ingested in four
equal portions throughout the day, for 5 days, then a
maintenance phase of 0.03 g/kg BW/day for 5
weeks) on training volume for male rowers. The
initial 5-day loading period of Cr did not improve
repeated interval rowing performance, 2000m rowing times or any strength measures. Following an
additional 5 weeks of Cr supplementation, still no
differences were noted between the two groups relative to any of the performance parameters.
In contrast to these two previous studies, RicoSanz and Marco investigated the effects of Cr
supplementation on VO2 and performance during
alternating bouts of exercise at different intensities.
Fourteen male subjects were randomly assigned to
either a Cr group (n = 7; 20 g/day for 5 days) or a
placebo group (n = 7). Cycling...
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