Abstract:
PURPOSE:The main purpose of the present study was to measure the total oxygen consumed, accumulation of blood metabolites, and performance during alternating intensity exercise before and after a period of creatine (Cr) loading in well-trained humans. METHODS:Fourteen males were randomly assigned to two groups of seven males and were tested before and after 5 d of placebo (PL) or Cr monohydrate (CR) loading (20 g x d(-1)). Oxygen uptake was measured using a breath-by-breath system during bicycle exercise alternating every 3 min between bouts at 30%(-30%) and 90% (-90%) of the maximal power output to exhaustion. Blood samples were also obtained at rest, before the end of each cycling load, at exhaustion, and 5-min postexercise. RESULTS:The oxygen consumed during 1-90% (5.08 +/- 0.39 L) and 2-90% (5.32 +/- 0.30 L) was larger after CR (5.67 +/- 0.34 and 5.78 +/- 0.35 L, P < 0.01 and P < 0.05, respectively). Blood ammonia accumulation at the end of 1-90% (23.1 +/- 6.5 micromol x L(-1)) and 3-30% (64.7 +/- 15.2 micromol x L(-1)) was lower after CR (P < 0.05), whereas plasma uric acid accumulation was lower at exhaustion (P < 0.05) and 5-min postexercise (P < 0.01). Time to exhaustion increased (P < 0.05) from 29.9 +/- 3.8 to 36.5 +/- 5.7 min after CR, whereas it remained the same after PL. CONCLUSIONS:The results indicate that Cr feeding increases the capacity of human muscle to perform work during alternating intensity contraction, possibly as a consequence of increased aerobic phosphorylation and flux through the creatine kinase system.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Rico-Sanz J,Mendez Marco MTdoi
10.1097/00005768-200002000-00018subject
Has Abstractpub_date
2000-02-01 00:00:00pages
379-85issue
2eissn
0195-9131issn
1530-0315journal_volume
32pub_type
临床试验,杂志文章,随机对照试验abstract::Relatively few studies have assessed the prospective relationship of sedentary lifestyle and coronary heart disease (CHD) in women. We performed a nested case-control study, identifying 50 cases of acute CHD in women and 150 age-matched controls. Risk factors including sedentary lifestyle, cigarette smoking, hypertens...
journal_title:Medicine and science in sports and exercise
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更新日期:1995-11-01 00:00:00
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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更新日期:1980-01-01 00:00:00
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doi:
更新日期:1993-08-01 00:00:00
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journal_title:Medicine and science in sports and exercise
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