Tools Critical Power and W’ Calculator Use our custom-built calculator to input your critical power test results to determine CP, W’ and to predict maximal output over specified durations. Use Our Calculator Key Workouts Guide Our free collection of 10 essential workouts you can use today to begin improving your endurance, threshold power, VO2max and other vital cycling abilities. Get Your Guide Lactate Testing Handbook Learn how to perform blood lactate testing on your own indoor trainer or even outdoors. Includes several key protocols, an equipment list and best practices for getting good data. Get Your Handbook