Preexercise meal affects ride time to fatigue in trained cyclists

Anderson, Marylou; Bergman, Ethan A.; Nethery, Vincent

doi:10.1016/0002-8223(94)91137-1

Cited by 8 publications

(7 citation statements)

References 12 publications

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“…A second important observation of this study was that ingestion of CHO before exercise did not alter exercise performance compared to the ingestion of an energy-free placebo. This finding is also consistent with the results of some earlier investigations (Anderson et al 1994;Chryssanthopoulos et al 1994;Febbraio et al 2000a;Hargreaves et al 1987;Maughan and Gleeson 1988;McMurray et al 1983;Scott van Zant and Lemon 1997), but is in contrast to those of others (el-Sayed et al 1997;Gleeson et al 1986;Neufer et al 1987;Ramires et al 1997;Sherman et al 1991;Speedy et al 1998), who found an increased exercise performance after ingesting CHO pre-exercise compared with placebo. Although the research findings on this topic are equivocal, only two studies have reported a negative effect on performance (Foster et al 1979;Keller and Schwarzkopf 1984).…”

Section: Discussionsupporting

confidence: 92%

Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance

et al. 2003

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Studies on the effect of the pre-exercise ingestion of carbohydrate on metabolism and performance have produced conflicting results, perhaps because of differences in the designs of the studies. The purpose of the present study was to examine the effects of ingesting differing amounts of glucose pre-exercise on the glucose and insulin responses during exercise and on time-trial (TT) performance. Nine well-trained male cyclists completed four exercise trials separated by at least 3 days. At 45 min before the start of exercise subjects consumed 500 ml of a beverage containing either 0 g (PLAC), 25 g (LOW), 75 g (MED) or 200 g (HIGH) of glucose. The exercise trials consisted of 20 min of submaximal steady-state exercise (SS) at 65% of maximal power output immediately followed by a [mean (SEM)] 691 (12) kJ TT. Plasma insulin concentrations at the onset of exercise were significantly higher ( P<0.05) in MED and HIGH compared with LOW and PLAC. Plasma glucose concentration fell rapidly ( P<0.05) during SS exercise in all glucose trials, but remained steady in PLAC. No difference in plasma glucose concentration was observed between the glucose trials at any time. Hypoglycaemia (less than 3.5 mmol.l(-1)) was observed in six subjects during SS but only after ingesting glucose pre-exercise. However, there was no difference in TT performance between the four trials. The ingestion of 0, 25, 75 or 200 g of glucose 45 min before a 20 min submaximal exercise bout did not affect subsequent TT performance. In addition, mild rebound hypoglycaemia following pre-exercise glucose ingestion did not negatively affect performance.

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Section: Discussionsupporting

confidence: 92%

Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance

et al. 2003

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“…As previously discussed, there is considerable contention in the literature regarding the effects of preexercise CHO ingestion on subsequent metabolic and performance responses (Foster et al 1979;Keller and Schwarzkopf 1984;Gleeson et al 1986;Hargreaves et al 1987;Maughan and Gleeson 1988;Okano et al 1988;Calles-Escandon et al 1991;Anderson et al 1994;Ventura et al 1994;Anantaraman et al 1995;Goodpaster et al 1996;Kirwan et al 1998;Palmer et al 1998;Sparks et al 1998;DeMarco et al 1999). Differences in methodologies have been suggested as an explanation for these disagreements and here we have investigated whether the differing timing of the CHO intake could have been responsible for the variable results.…”

Section: Discussionmentioning

confidence: 84%

Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance

2003

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The occurrence of rebound hypoglycaemia may depend on the timing of carbohydrate intake. The aim of the present study was to investigate the metabolic and performance responses to the ingestion of carbohydrate at differing times before exercise. Eight subjects [mean (SEM)] [28 (3) years, 74.5 (2.6) kg, maximal oxygen uptake 63.1 (3.1) ml.kg(-1).min(-1)] performed three experiments. They ingested 75 g glucose dissolved in 500 ml water, thereafter resting for either 15, 45 or 75 min (15-Pre, 45-Pre and 75-Pre) before exercising for 20 min at 65% maximal power output followed by a time trial [total work 685 (18) kJ]. There were no differences in performance between conditions [mean powers 268 (10), 269 (7) and 276 (12) W for 15-Pre, 45-Pre and 75-Pre, respectively]. There were significant differences in plasma glucose concentration between 15-Pre [6.6 (0.6) mmol.l(-1); P<0.05] and both 45-Pre [4.5 (0.2) mmol.l(-1)] and 75-Pre [3.7 (0.2) mmol.l(-1)] immediately before exercise. Insulin concentrations immediately before exercise were higher ( P<0.05) during 15-Pre [72.6 (10.4) microU.ml(-1)] than during 45-Pre [50.8 (9.9) microU.ml(-1)], which was higher ( P<0.05) than during 75-Pre [33.9 (5.5) microU.ml(-1)]. These differences disappeared within 10 min of exercise. Two subjects became hypoglycaemic (plasma glucose concentration of less than 3.5 mmol.l(-1)) in the 15-Pre while three and five subjects were transiently hypoglycaemic in the 45-Pre and 75-Pre, respectively. Performance and rating of perceived exertion did not seem to be related to hypoglycaemia. Altering the timing of the ingestion of carbohydrate before exercise resulted in differences in plasma glucose/insulin responses which disappeared within 10 min of exercise and which had no effect on performance. Hypoglycaemia was observed in some subjects during the first 10 min but this did not affect performance.

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“…Of these, 54% found that pre‐exercise feeding improved performance, while the remainder evidenced no difference between fasted and fed groups . Regarding studies showing a beneficial effect of acute pre‐exercise feeding on aerobic exercise performance, 1 provided a mixed meal, 1 implemented a high‐carbohydrate meal, and 5 provided predominantly carbohydrate as an energy source . A further 7 studies evaluated markers of shorter duration (<60 minutes) aerobic performance .…”

Section: Resultsmentioning

confidence: 99%

“…Meal composition and GI remain topics of debate in sports nutrition, and its effects on performance were compared in 4 studies . Of these studies, 75% determined that ingesting low/moderate GI carbohydrates pre‐exercise improved prolonged aerobic capacity compared with fasting conditions, while high GI carbohydrates did not enhance performance.…”

Section: Discussionmentioning

confidence: 99%

“…Most studies in this review evaluated the effects of fasted vs fed exercise on performance during continuous long-duration aerobic exercise (>60 minutes). Of these, 54% found that pre-exercise feeding improved performance, 31,47,54,55,61,67,72 while the remainder evidenced no difference between fasted and fed groups. 30 a beneficial effect of acute pre-exercise feeding on aerobic exercise performance, 1 provided a mixed meal, 61 1 implemented a high-carbohydrate meal, 67 and 5 provided predominantly carbohydrate as an energy source.…”

Section: Aerobic Exercisementioning

confidence: 99%

See 1 more Smart Citation

Effects of fasted vs fed‐state exercise on performance and post‐exercise metabolism: A systematic review and meta‐analysis

Aird

Davies

Carson

2018

Scandinavian Med Sci Sports

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The effects of nutrition on exercise metabolism and performance remain an important topic among sports scientists, clinical, and athletic populations. Recently, fasted exercise has garnered interest as a beneficial stimulus which induces superior metabolic adaptations to fed exercise in key peripheral tissues. Conversely, pre-exercise feeding augments exercise performance compared with fasting conditions. Given these seemingly divergent effects on performance and metabolism, an appraisal of the literature is warranted. This review determined the effects of fasting vs pre-exercise feeding on continuous aerobic and anaerobic or intermittent exercise performance, and post-exercise metabolic adaptations. A search was performed using the MEDLINE and PubMed search engines. The literature search identified 46 studies meeting the relevant inclusion criteria. The Delphi list was used to assess study quality. A meta-analysis and meta-regression were performed where appropriate. Findings indicated that pre-exercise feeding enhanced prolonged (P = .012), but not shorter duration aerobic exercise performance (P = .687). Fasted exercise increased post-exercise circulating FFAs (P = .023) compared to fed exercise. It is evidenced that pre-exercise feeding blunted signaling in skeletal muscle and adipose tissue implicated in regulating components of metabolism, including mitochondrial adaptation and substrate utilization. This review's findings support the hypothesis that the fasted and fed conditions can divergently influence exercise metabolism and performance. Pre-exercise feeding bolsters prolonged aerobic performance, while seminal evidence highlights potential beneficial metabolic adaptations that fasted exercise may induce in peripheral tissues. However, further research is required to fully elucidate the acute and chronic physiological adaptations to fasted vs fed exercise.

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Preexercise meal affects ride time to fatigue in trained cyclists

Cited by 8 publications

References 12 publications

Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance

Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance

Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance

Effects of fasted vs fed‐state exercise on performance and post‐exercise metabolism: A systematic review and meta‐analysis

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