Simple formula for planning TSS for outdoor rides


I like to plan my TSS for the week ahead of time. It’s easy for TR workouts, since the TSS is listed, but for outdoor rides, it’s helpful to know the formula for TSS. It is the following:

IF * IF * 100 * Hours

So, if I feel I need to get about 100 TSS for an endurance ride, where I’ll be riding at 68% of FTP, then I know I’ll be generating 0.68 * 0.68 * 100 = 46.24 TSS per hour, so I’ll need 100 / 46.24 = 2.16 hours or about 2 hours and 9 minutes.

Forgive me if it’s obvious, but I’ve found that little formula super handy when planning my week.