Guarana (Paullinia cupana) but Not Low-Dose Caffeine Improves Cycling Time-Trial Performance Versus Placebo

Int J Sport Nutr Exerc Metab. 2023 Oct 28:1-8. doi: 10.1123/ijsnem.2023-0148. Online ahead of print.ABSTRACTGuarana (GUA) seed extract, containing caffeine (CAF) and additional bioactive compounds, may positively affect mental performance, but evidence regarding exercise is limited. This investigation assessed acute GUA ingestion compared with CAF on endurance performance. Eleven endurance-trained noncyclists and cyclists (V˙O2peak = 49.7 ± 5.9, 60.4 ± 4.6 ml·kg·min-1) completed a double-blind, crossover experiment after ingesting (a) 100 mg CAF, (b) 500 mg GUA (containing 130 mg CAF), or (c) placebo (P) prior to 60-min fixed cycling workload (FIX) + 15-min time trial. Oxygen uptake, heart rate, respiratory exchange ratio, blood glucose, and lactate were not different (p ≥ .052) during FIX. A significant interaction (p = .042) for perceived exertion was observed at 50-min FIX with lower rating (p = .023) for GUA versus CAF but not compared with P. Work accumulated over 15-min time trial was greater (p = .038) for GUA versus P due to higher early (1-11 min) work outputs. Work performance favored (effect size = 0.18; 95% confidence interval [0.003, 0.355], p = .046) GUA (241.4 ± 39.9 kJ) versus P (232.1 ± 46.6 kJ), but CAF (232.3 ± 43.9) was not different from GUA (effect size = 0.19; 95% confidence interval [-0.022, 0.410], p = .079) or P. Postexercise strength loss was not attenuated with GUA (-5.6 ± 8.5%) or CAF (-8.3 ± 9.4%) versus P (-10.3 ± 5.1%). Acute GUA i...
Source: International Journal of Sport Nutrition and Exercise Metabolism - Category: Sports Medicine Authors: Source Type: research