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The effects of varying caffeine levels in a carbohydrate‐containing sports drink on the metabolism and performance of triathletes
Author(s) -
Borgard Chris patrick,
OˈHara Christie,
LaGuire Tiev C,
Reaves Scott K
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1145.2
Subject(s) - caffeine , respiratory exchange ratio , chemistry , placebo , treadmill , carbohydrate , zoology , heart rate , endocrinology , medicine , biochemistry , biology , blood pressure , alternative medicine , pathology
The objectives of the study included the development of a sports drink using a novel combination of carbohydrates, caffeine, electrolytes and antioxidants and to test its effects on endurance performance using a randomized, double‐blind design that included two test formulas with different levels of caffeine and a placebo control beverage (P). The two test beverages were 6% carbohydrate (CHO) and only varied in their caffeine content. The low caffeine formula (CHO/LC) contained 10.6 mg caffeine per 100 ml beverage and the high caffeine formula (CHO/HC) contained twice that amount (21.2 mg/100 mL). Ten male collegiate triathletes were tested once with each beverage with a one week washout period. Each test included a 20‐minute swim followed immediately by a 70‐minute cycling event and then a graded treadmill run to exhaustion of approximately 25 minutes. Beverages were provided 30 minutes prior to the swim and at three other points during exercise. Respiratory exchange ratio (RER) data suggested similar substrate use in the CHO/LC and CHO/HC and each had higher RERs compared to P. Times to exhaustion and average VO2max at the end of the run for CHO/LC and CHO/HC were both greater than P but CHO/LC vs. CHO/HC were not significantly different. Overall, substrate use was altered and performance enhanced in CHO/LC and CHO/HC compared to P but the additional caffeine in the CHO/HC group did not further improve performance.