Training Peaks, Specificity, Coach Cliff Scherb

★★★How to know you are "hitting your key sessions" with intensity factor

Learn more about whether or not you are ready for your upcoming race with this key metric

What is intensity factor in Cycling? 

Although normalized power is a better measure of training intensity than average power, it does not take into account differences in fitness within or between individuals. TrainingPeaks therefore also calculates an intensity factor (IF) for every workout or time range analyzed. IF is simply the ratio of the normalized power as described above to your threshold power (entered under "Athlete Settings" at your "Athlete Home"). For example, if your normalized power for a long training ride done early in the year is 210 W and your threshold power at the time is 280 W, then the IF for that workout would be 0.75. However, if you did that same exact ride later in the year after your threshold power had risen to 300 W, then the IF would be lower, i.e., 0.70. IF therefore provides a valid and convenient way of comparing the relative intensity of a training session or race either within or between riders, taking into account changes or differences in threshold power. Typical IF values for various training sessions or races are as follows:

Typical IF values for various training sessions or races are as follows:

  • Less than 0.75 recovery rides

  • 0.75-0.85 endurance-paced training rides

  • 0.85-0.95 tempo rides, aerobic and anaerobic interval workouts (work and rest periods combined), longer (>2.5 h) road races

  • 0.95-1.05 lactate threshold intervals (work period only), shorter (<2.5 h) road races, criteriums, circuit races, longer (e.g., 40 km) TTs

  • 1.05-1.15 shorter (e.g., 15 km) TTs, track points race

  • Greater than 1.15 prologue TT, track pursuit, track miss-and-out

Note that one particularly useful application of IF is to check for changes in threshold power - specifically, an IF of more than 1.05 for a race that is approximately 1 hour in duration is often a sign that the rider's threshold power is actually greater than that presently entered into the program. Thus, by simply examining a rider's IF for various events during the course of a season, increases or decreases in threshold power can often be revealed without the need for frequent formal testing.