A novel bitter solution can increase short-term power output in a 3 km cycling time-trial

Introduction: Track cycling includes short and very high intensity events such as the team pursuit. Maximal 30 s cycling performance can be improved by ingestion of a bitter drink (quinine)1, but it is unclear whether the effects last long enough to enhance 3 km maximal time trial (TT) performance. We quantified the effects of 2 mM quinine ingestion prior to a 3 km maximal cycling TT. Methods: Nine well-trained male cyclists (mass 78 ± 11 kg; height 181 ± 7 cm and maximal aerobic power 386 ± 38 W; mean ± SD) performed a maximal incremental test, three 3 km familiarisation trials and four different 3 km time trials in a total of 8 separate visits to the laboratory. The four treatments administered in a randomised and counterbalanced manner were: 1) 25 ml of water, 2) a 25 ml sweet solution (placebo) and 3) and 4) repeat 2mM quinine solutions, 30 s prior to the commencement of each trial. Each time trial was performed on a VelotronR cycle ergometer with participants being blind to power output, cadence and other feedback except for distance covered.
Participants were allowed to self-select their gears and free to change gears during the time trials. Power output (W) was monitored continuously during all trials. Descriptive statistics are represented as mean ± SD and differences between the interventions are specified as standardized mean difference ± 90% confidence limits. Results: There was no substantial ergogenic effect of quinine on 3 km TT cycling performance. Mean power output for all four conditions was
similar: 348 ± 45 W (water), 354 ± 47 W (quinine1); 355 ± 47 W (sweet), and 355 ± 48 (quinine2). Quinine administration increased power output during the first km by ~18 ± 9 W over water, followed by a decay in power output in the final stages. Discussion: It appears ingesting 2mM of quinine improves cycling performance during the first 1/3 of a 3 km TT but there is also a greater decay in power output during the rest of the TT. Quinine does not appear to improve an individual 3 km performance and might only be useful for short-term (~30s) efforts. The elevated power output during 1st km could be exploited in the team pursuit event by supplementing the lead-off rider.