INTRODUCTION: Cycling has been the subject of numerous studies. Among these, measuring muscular performance during cycling has attracted much interest. OBJECTIVE: To investigate the relationship between Wattbike® and isokinetic findings in a group of cyclists. METHODS: Thirty-seven male cyclists performed a 30-s anaerobic power test on a Wattbike® and then were tested concentrically for knee extensor and flexor strength using isokinetic dynamometry. RESULTS: There was a positive fair-to-moderate correlation between the peak moment, peak power, and total work derived from the Wattbike® and the respective parameters evaluated isokinetically. CONCLUSION: While the findings exclude interchangeability of the two methods, the fact that total work is the most closely associated parameter among the measurements highlights its importance as an outcome measure in muscle performance in cyclists.