Flattened cola improves high-intensity interval performance in competitive cyclists.

Abstract

Some cyclists consume flattened cola during competitive events, but limited research has investigated if cola beverages elicit ergogenic effects, particularly on high-intensity exercise performance. Whether the potentially beneficial effects of cola are due to the caffeine and/or the carbohydrate content is also unclear. This study assessed the ergogenic effects of different cola beverages on performance during a constant power bout (CPB) and subsequent high-intensity interval efforts in competitive cyclists. In a randomized, double-blind, cross-over design, competitive cyclists (n = 13; [Formula: see text]O2max 65.7 ± 5.9mlkg-1min-1) completed a 45-min CPB at 69% of maximum workload (Wmax), followed by four maximal 1-min high-intensity intervals (HII) against a resistance of 0.5Nkg-1. Participants consumed 16mlkg-1 total (intermittantly at four time points) of flattened decaffinated diet cola (PLA), caffeinated diet cola (CAF) or cola containing caffeine and carbohydrates (CAF + CHO). During the CPB, ratings of perceived exertion were lower in the CAF + CHO and CAF conditions compared to PLA (both, P < 0.04). Compared to PLA, CAF + CHO and CAF similarly increased (all, P < 0.049) mean power (CAF + CHO: 448 ± 51W; CAF: 448 ± 50W; PLA: 434 ± 57W), minimum power (CAF + CHO: 353 ± 45W; CAF: 352 ± 51W; PLA: 324 ± 49W) and total work (CAF + CHO: 26.9 ± 3.1kJ; CAF: 26.9 ± 3.0kJ; PLA: 26.0 ± 3.4kJ), but not peak power (CAF + CHO: 692 ± 117W; CAF: 674 ± 114W; PLA: 670 ± 113W; all, P > 0.57) during the HII. Cola containing caffeine with or without carbohydrates favorably influenced perceived effort during the CPB and enhanced mean and minimum power during repeated maximal intervals. We provide evidence supporting the consumption of commercially available cola for high-intensity cycling in competitive cyclists.