Combined caffeine and ephedrine ingestion improves run times of Canadian Forces Warrior Test

The ingestion of a combination of caffeine (C) and ephedrine (E) has been r eported to prolong exercise time to exhaustion during cycle ergometry at 85 % (V) over dot O(2)max. The present study was undertaken to investigate whe ther this enhancement would occur in a field setting and ii drug ingestion on 1 d would affect performance 1 d later. Two hours after ingesting either a combination of 375 mg of C and 75 mg E (C+E), or a placebo (P), 9 health y male recreational runners completed six balanced and double-blind trials of the Canadian Forces Warrior Test (WT), a 3.2 km run wearing "fighting or der" which weighed about 11 kg. The trials were performed in sets of two ru ns, i.e., two runs were done 24 h apart, and these sets were separated by a minimum of 7 d. The sets were: C+E trial on day 1 (D1), placebo on day 2 ( P2); placebo first (P1), C+E second (D2); and placebo first (P3), placebo s econd (P4). In addition, 1 wk before the treatment trials the subjects perf ormed a control trial WT. During the WT, heart rates (HR) were recorded eve ry minute. Plasma C and E levels immediately before the WT were similar for both C+E trials, but were undetectable for all P trials. Run times (mean /- SD) were 15.3 +/- 0.6, 15.4 +/- 0.9, 15.5 +/- 1.2, 15.4 +/- 0.9, 15.4 +/ - 0.9, 14.8 +/- 0.7, and 14.6 +/- 0.8 min for control, P1, P2, P3, P4, D1, D2 trials, respectively. The two C+E trial run times were similar and both were significantly raster (p < 0.05) than control and all placebo trials. H R during the WT was significantly higher (p < 0.05) for the C+E trials comp ared with the other trials. WT performance was not impaired by C+E ingestio n 24 h earlier. In conclusion, performance of the WT was improved by ingest ion of C+E.