ISSN:
1439-6327
Keywords:
Glucose ingestion
;
Prolonged exercise
;
Daily exercise
;
Performance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effect of glucose (Glc) ingestion before and during daily, repeated, prolonged exercise on metabolism and performance was tested. Seven young, healthy males performed cycling exercise in two series, with 1 month interval. Each exercise series consisted of 1 h/day on 3 successive days. On the 3rd day, exercise was continued until exhaustion. The intensity was 73.4 (7.7) % [mean (SD)] of maximal oxygen uptake ( $$\dot VO_{2\max } $$ ). Glucose (Glc) or placebo (P) drink was ingested 15 min before the start, and at 15 and 45 min of each daily exercise. The total amount of Glc ingested was 43.1 (4.2) g. During exercise, blood Glc concentrations were significantly higher (P〈0.05) when Glc was ingested than when P was ingested [Glc 5.14 (0.32) and P 4.12 (4.17) mmol · 1−1 at exhaustion]. However, Glc ingestion did not improve performance time to exhaustion [Glc 92.05 (29.55) and P 98.07 (27.33) min]. Free fatty acid concentrations were significantly lower when Glc was ingested than when P was ingested [Glc 0.63 (0.21) and P 1.39 (0.46) mmol · l−1 at exhaustion]. There were no significant differences in exercise heart rate, $$\dot VO_2 $$ , respiratory exchange ratio, blood lactate concentrations or rating of perceived exertion between the conditions nor were there any significant differences in these parameters on different days of exercise. It seems that ingestion of small amounts of Glc does not increase the metabolism of carbohydrate or improve the performance of intensive endurance exercise of poorly trained subjects, even when the exercise is repeated daily.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00863402
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