The aim of this study was to assess the test–retest reliability of the CyclotronicsSmart Trainer during a graded exercise test (GXT) and a power profile test (PPT) in trained cyclists. For the GXT reliability analysis, 22 cyclists performed three GXTs, each separated by seven days. For the PPT reliability assessment, a smaller group of 10 trained participants (2 females, including 1 triathlete and 7 cyclists) completed one GXT followed by three PPTs, also separated by seven days.