González-Haro, C. Differences in physiological responses between short- vs. long-graded laboratory tests in road cyclists. J Strength Cond Res 29(4): 1040–1048, 2015—This study aimed to determine the effect of a short-graded with respect to a long-graded protocol laboratory test on the physiological responses of road cyclists. Twenty well-trained road cyclists performed a short-graded and long-graded laboratory tests within 1 week of each other in a randomized and crossover study design. Blood lactate concentration ([La−]b), heart rate (HR), oxygen consumption (
), and carbon dioxide production (
) were measured. Fat and carbohydrate oxidation rates (FATOxR and CHOOxR) were estimated at the end of each stage during the short-graded and the long-graded (10th minute: T2.10) and in the middle of long-graded (fifth minute: T2.5) protocol. Lactate threshold (LT) and individual anaerobic threshold (IAT) were calculated. For maximal intensities, duration and maxFATOxR were significantly higher in long-graded with respect to short-graded protocols. Peak power output (POPeak), HRPeak, [La−]bmax,
, and maxCHOOxR were significantly higher in short-graded with respect to long-graded protocols. At submaximal intensities, short-graded protocol provoked higher demands on glycolytic metabolism than long-graded protocol; no differences were illustrated for HR or
between protocols. Crossover concept shifted to higher intensities in long-graded with respect to short-graded protocols due to the higher lipolytic response during the long-graded protocol. Both LT and IAT were reached at the same %
, although significantly higher PO in short-graded with respect to long-graded protocols was reached. The long-graded proved to be more specific than the short-graded protocol to assess the physiological responses of road cyclists based on relative PO (W·kg−1).