Effects of Pre-Exercise High and Low Glycaemic Meal on Intermittent Sprint and Endurance Exercise Performance

Abstract

The purpose of this study is to investigate the effects of ingesting either a high glycaemic index (HGI) or low glycaemic index (LGI) carbohydrate meal (preceding a 12 h overnight fast and where the meal was ingested 45-min prior to activity) on intermittent sprint and endurance exercise performance. Ten male varsity athletes from intermittent sports (age 23.6 ± 1.7 years, VO2max 51.9 ± 4.7 mL·kg−1·min−1) underwent a peak velocity (Vpeak) test and familiarisation session, followed by two experimental sessions in random order. Experimental sessions involved the ingestion of either an HGI or LGI meal, followed by the completion of the modified Loughborough Intermittent Shuttle Test (mLIST). There was no significant difference between HGI or LGI meals on sprint times (p = 0.62) and distance to exhaustion (p = 0.54) in the mLIST. Exercise heart rate, blood lactate and ratings of perceived exertion were also similar between the two meal trials throughout the mLIST (all p > 0.05). Subjective ratings of hunger, fullness, satiety and satisfaction were also not significantly different between the two meals. In conclusion, consuming either an HGI or LGI meal after a prolonged 12 h fast and ingesting the meal 45 min prior to exercise did not differ in either physiological, subjective and intermittent sprint and endurance performance outcomes.

Low- and High-Glycemic Index Foods and Exercise Performance

“…They included 10 male varsity athletes from various sports (mean age: 23.6 ± 1.7 years, maximal oxygen consumption [V̇O 2max ]: 51.9 ± 4.7 mL/kg/min) in this single-blind, randomized, cross-over study. In contrast to Kaviani et al’s (9) results, Chua et al (10) did not report any significant differences between the low- and high-glycemic index meals on sprint times, distance to exhaustion, heart rate, blood lactate concentrations, ratings of perceived exertion, hunger, fullness, or satiety. Based on these data, it seems that low- or high-glycemic index foods provide similar benefits in short, intermittent exercise.…”

“…In a similar design, Chua et al (10) assessed the effects of consuming a low- or high-glycemic index carbohydrate meal 45 minutes before the Loughborough Intermittent Shuttle Test. They included 10 male varsity athletes from various sports (mean age: 23.6 ± 1.7 years, maximal oxygen consumption [V̇O 2max ]: 51.9 ± 4.7 mL/kg/min) in this single-blind, randomized, cross-over study.…”

“…Based on these data, it seems that low- or high-glycemic index foods provide similar benefits in short, intermittent exercise. In addition, Chua et al (10) provided their participants with meals, whereas Kaviani et al (10) provided their participants with energy bars.…”

Reactive hypoglycemia – an interdisciplinary approach of the disease of XXI Century

“…Trzeba jednak brać pod uwagę fakt, że u osób zdrowych podczas wzmożonej aktywności fizycznej glikemia może obniżać się nawet do 30−50 mg/dl. Na występowanie niedocukrzenia mogą mieć wpływ: rodzaj, intensywność i długość trwania treningu, skład posiłku spożytego przed podjęciem aktywności fizycznej, jak i stopień nawodnienia [11]. W wypadku nawracających spadków glikemii z towarzyszącymi objawami hipoglikemii podczas aktywności fizycznej konieczne jest poszerzenie diagnostyki w kierunku innych schorzeń towarzyszących.…”