Table 1.
Summary of studies exploring the effects of pre-exercise CHO food ingestion on endurance exercise performance.
| Study | Subjects | Exercise Test | Treatments | Timing | Performance |
|---|---|---|---|---|---|
| Thomas et al. [31] | 8 trained male cyclists (V̇O2max: 62.5 ± 3.7 mL·kg−1·min−1) | Cycling to exhaustion at 65–70% V̇O2max | L: 1 g·kg−1 CHO from lentils (LGI) P: 1 g·kg−1 CHO potato (HGI) G:1 g·kg−1 CHO glucose W: Water |
1 h before exercise | ↑L vs. G ↑L vs. P ↑L vs. W |
| Paul et al. [37] | 12 healthy adults (six women V̇O2peak: 50.6 ± 4.3; six men V̇O2peak:58.3 ± 5.1 mL·kg−1·min−1 |
90 min of steady state cycling at 60% V̇O2peak followed by a 6.4 km TT |
Oats (O): 41.5 g CHO, 5.7 g fibre, 3.8 g fat, 10 g protein Wheat (W): 53.9 g CHO, 7.2 g fibre, 1.4 g fat, 7.2 g protein Corn (C): 54.7 g CHO, 0.7 g fibre, 0 g fat, 4.5 g protein Fasted (F) |
90 min before cycling | ↔O vs. W vs. C |
| Chryssanthopoulos et al. [28] | 10 male recreational runners (V̇O2max: 58.6 ± 1.9 mL·kg−1·min−1) |
Treadmill running at 70% V̇O2max to exhaustion | M + C: Pre-exercise 2.5 g·kg−1 BM CHO [white bread, jam, cornflakes, sugar, skimmed milk, orange juice], and CHO drinks during exercise [6.9% CHO: dextrose, maltodextrin, and glucose syrup] P + C: Pre-exercise PL and CHO ingestion during exercise P + P: Pre-exercise PL and PL drink during exercise |
3 h before exercise and during exercise | ↑M + C vs. P + C ↑M + C vs. P + P ↑P + C vs. P + P |
| Jones et al. [38] | 8 endurance trained males | 60 min self-paced cycle | (Combo): Semi-liquid oat-based CHO/fat/protein combination (77% CHO, 7% protein and 5% fat) [Oatmeal, sugar, whole wheat, brown sugar, dried bananas, barley flakes, wheat farina, almonds, and guar gum] (O): Semi-liquid, oat-based CHO (68% CHO,14% protein and 1.7% fat) [Whole-grained rolled oats, calcium carbonate, and guar gum] (W): Semi-liquid wheat-based CHO (75% CHO, 11% protein) [Wheat farina, wheat germ, salt, guar gum (460 kcal] (Bar): Dense solid, fructose-based CHO/protein/vitamin (69% CHO, 14% protein, 3% fat) [High fructose corn syrup, fruit juice concentrate, oat bran, malto-dextrins, milk protein, banana, cashew butter, rice] |
2 h before the test | ↔Combo vs. O vs. W vs. Bar |
| Kirwan et al. [39] | 6 recreationally active women (V̇O2max: 48.3 ± 3.0 mL·kg−1·min−1) |
TTE at 60% V̇O2max | (R): 75 g CHO [sweetened whole-grain rolled oats with 7 g fibre + 300 mL water] (F): 75 g CHO [sweetened whole-oat flour with 3 g fibre + 300 mL water] (C): Control [Water] |
45 min before exercise | ↑R vs. C ↑F vs. C |
| Mitchell et al. [33] | 10 trained runners (V̇O2max: 59.35 ± 2.46 mL·kg−1·min−1) | 10 km treadmill run | HGF: 72 g CHO high fructose corn syrup solution LFG: 54 g CHO low volume glucose/fructose GLU: 54 g CHO glucose solution SUG: 54 g CHO sucrose/glucose mixture BAN: 54 g CHO banana with water (900 mL) WP: Water PL |
1 h before exercise | ↔HGF vs. LFG vs. GLU vs. SUG vs. BAN vs. WP |
| Kirwan et al. [40] | 6 males (V̇O2peak: 54.3 ± 1.2 mL·kg−1·min−1) |
Cycling to exhaustion at 60% V̇O2peak | (O): 75 g CHO [rolled oats as a moderate GI meal (~61) + 300 mL water] (P): 75 g CHO [Puffed rice as a HGI meal (~82) + 300 mL of water] (C): Control [Water] |
45 min before exercise | ↑O vs. C ↔P vs. C |
| Chryssanthopoulos et al. [44] | 10 male recreational runners (V̇O2max: 63.5 ± 2.3 mL·kg−1·min−1) |
Treadmill running at 70% V̇O2max to exhaustion | M + C: Pre-exercise 2.5 g·kg−1 BM CHO [white bread, jam, cornflakes, sugar, skimmed milk, orange juice], and CHO drinks during exercise [6.9% CHO: dextrose, maltodextrin, and glucose syrup] M + W: Pre-exercise 2.5 g·kg−1 BM CHO [white bread, jam, cornflakes, sugar, skimmed milk, orange juice], and water during exercise P + W: Pre-exercise PL and water during exercise |
3 h before exercise and during exercise | ↑M + C vs. P + W ↑M + W vs. P + W |
| Kern et al. [35] | 8 endurance-trained cyclists 4 males (V̇O2max: 64.1 ± 3.4 mL·kg−1·min−1) and 4 females (V̇O2max: 47.5 ± 10.6 mL·kg−1·min−1) |
Cycling for 45 min at 70% V̇O2max followed by 15 min performance trial | R: 1 g·kg−1 BW CHO raisin S: 1 g·kg−1 BW CHO sport gel |
45 min before exercise | ↔R vs. S |
| Chen et al. [41] | 8 endurance-trained male runners (V̇O2max: 58.5 ± 1.6 mL·kg−1·min−1) | 21 km performance run on a level treadmill | HGI meal: [92 g jasmine rice, 90 g parsnips, 265 g orange soda, 55 g canned lychees, 40 g ham, 35 g fish sticks, 80 g egg, 573 g water] LGI meal: [290 g clear chicken broth, 251 g soymilk, 54 g hard boiled egg, 38 g fish sticks, 46 g green peas, 81 g mung bean thread noodles, 467 g water] CON: Control [9 g low-energy sugar-free jelly] |
2 h before the test meal was consumed and 2 mL·kg−1 BM of 6.6% CHO solution was consumed immediately before exercise and every 2.5 km afterward |
↔LGI vs. HGI: ↑HGI vs. CON |
| Aandahl et al. [29] | 11 well-trained (V̇O2max: 71.9 ± 5.1 mL·kg−1·min−1) and 10 recreationally trained (V̇O2max: 46.9 ± 2.5 mL·kg−1·min−1) men | Five submaximal 5 min constant-velocity bouts of increasing intensity and a graded exercise test to measure TTE (running on a tread-mill) | High CHO meal: 3 g·kg−1 BM CHO [white bread, jam, skimmed milk, oats, banana, and raisins] Low CHO meal: 0.5 g·kg−1 BM [yogurt, almonds, and avocado] Fasted state |
3.5 h before the exercise | ↑High CHO meal vs. low CHO meal ↑High CHO vs. fasted state |
CHO carbohydrate, V̇O2max maximal oxygen consumption, V̇O2peak peak oxygen consumption, TT time-trial, TTE time to exhaustion, VA voluntary activation, CAR central activation ratio, MVC maximum voluntary contraction, sMVC sustained MVC, WE work economy, HGI high-glycaemic index, LGI low-glycaemic index.