Pre-Exercise Carbohydrate Meal and Endurance Running Capacity when Carbohydrates are Ingested During Exercise

Department of Physical Education, Sports Science and Recreation Management, Loughborough University, England, UK.
International Journal of Sports Medicine (Impact Factor: 2.07). 10/1997; 18(7):543-8. DOI: 10.1055/s-2007-972679
Source: PubMed


This study examined whether combining a pre-exercise carbohydrate meal with the ingestion of a carbohydrate-electrolyte solution during exercise is better in improving endurance running capacity than a carbohydrate-electrolyte solution alone. Ten men completed three treadmill runs at 70% VO2max to exhaustion. They consumed 1.) a carbohydrate meal three hours before exercise and a carbohydrate-electrolyte solution during exercise (M + C), or 2.) a liquid placebo three hours before exercise and the carbohydrate-electrolyte solution during exercise (P + C), or 3.) a placebo three hours before exercise and placebo during exercise (P + P). When the meal was consumed (M + C) serum insulin concentrations were higher at the start of exercise, and carbohydrate oxidation rates were higher during the first 60 min of exercise compared with the values found in the P + C and P + P trials (p < 0.01). Exercise time was longer in the M + C (147.4+/-9.6 min) compared with the P + C (125.3+/-7 min) (p < 0.01). Also, exercise time was longer in M + C and P + C compared with the P + P (115.1+/-7.6 min) (p < 0.01 and p < 0.05 respectively). These results indicate that the combination of a pre-exercise carbohydrate meal and a carbohydrate-electrolyte solution further improves endurance running capacity than the carbohydrate-electrolyte solution alone.

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Available from: Costas Chryssanthopoulos, Apr 30, 2014
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    • "Therefore, sports nutrition guidelines promote a variety of options for acutely increasing carbohydrate availability for an exercise session, including consuming carbohydrate before, during and in the recovery period between prolonged exercise bouts (American Dietetic Association et al., 2009). When these strategies enhance or maintain carbohydrate availability, they delay the onset of fatigue, and enhance exercise capacity or endurance (Wright et al., 1991; Fallowfield & Williams, 1993; Chryssanthopoulos & Williams, 1997). Studies that show benefits of carbohydrate support to exercise performance are more appropriate to sport (Sherman et al., 1991; Below et al., 1995; Tsintzas et al., 1995; Vergauwen et al., 1998), and even include protocols in which increased carbohydrate availability has enhanced performance in field situations or actual sports competition (Karlsson & Saltin, 1971; Akermark et al., 1996; Balsom et al., 1999). "
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    ABSTRACT: Availability of carbohydrate as a substrate for the muscle and central nervous system is critical for the performance of both intermittent high-intensity work and prolonged aerobic exercise. Therefore, strategies that promote carbohydrate availability, such as ingesting carbohydrate before, during and after exercise, are critical for the performance of many sports and a key component of current sports nutrition guidelines. Guidelines for daily carbohydrate intakes have evolved from the "one size fits all" recommendation for a high-carbohydrate diets to an individualized approach to fuel needs based on the athlete's body size and exercise program. More recently, it has been suggested that athletes should train with low carbohydrate stores but restore fuel availability for competition ("train low, compete high"), based on observations that the intracellular signaling pathways underpinning adaptations to training are enhanced when exercise is undertaken with low glycogen stores. The present literature is limited to studies of "twice a day" training (low glycogen for the second session) or withholding carbohydrate intake during training sessions. Despite increasing the muscle adaptive response and reducing the reliance on carbohydrate utilization during exercise, there is no clear evidence that these strategies enhance exercise performance. Further studies on dietary periodization strategies, especially those mimicking real-life athletic practices, are needed.
    Scandinavian Journal of Medicine and Science in Sports 10/2010; 20 Suppl 2(s2):48-58. DOI:10.1111/j.1600-0838.2010.01185.x · 2.90 Impact Factor
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    • "One obvious question is whether or not drinking a carbohydrate-electrolyte solution during prolonged running improves endurance capacity more than the combination of a high-carbohydrate pre-exercise meal and a carbohydrate-electrolyte solution during exercise. Chryssanthopoulos and Williams (1997) attempted to answer this question by comparing the endurance running capacity of ten runners who completed three trials. In one trial the participants ate a high-carbohydrate meal (2.5 g Á kg BM "
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    ABSTRACT: What players should eat on match day is a frequently asked question in sports nutrition. The recommendation from the available evidence is that players should eat a high-carbohydrate meal about 3 h before the match. This may be breakfast when the matches are played around midday, lunch for late afternoon matches, and an early dinner when matches are played late in the evening. The combination of a high-carbohydrate pre-match meal and a sports drink, ingested during the match, results in a greater exercise capacity than a high-carbohydrate meal alone. There is evidence to suggest that there are benefits to a pre-match meal that is composed of low-glycaemic index (GI) carbohydrate foods rather than high-GI foods. A low-GI pre-match meal results in feelings of satiety for longer and produces a more stable blood glucose concentration than after a high-GI meal. There are also some reports of improved endurance capacity after low-GI carbohydrate pre-exercise meals. The physical demands of soccer training and match-play draw heavily on players' carbohydrate stores and so the benefits of good nutritional practices for performance and health should be an essential part of the education of players, coaches, and in particular the parents of young players.
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