I got a private coach to help me with form and strength, and her group uses training peaks. Hello, I'm a middle distance runner! Training Peaks is for slow hobby joggers who can't run a 6 min mile! They look at my 4:47 and say, "Wow, you must have terrible endurance" because they need to feel good about their inferior speed. News Flash triathletes, running faster is more impressive.
Enough with the rant, but Training Peaks seems to be for cyclists and triathletes. Just to see, I did some sample calculations with some workouts I know to be very challenging, but Training peaks said, "Your TSS was under 150, so you shouldn't feel fatigued tomorrow". If I ran 10 400s at mile pace with 60s rest, it would tell me the workout was useless since it was only 20min. Meanwhile, I could almost walk for 2.5 hours and it would tell me I worked harder. I guess triathletes just slow jog and cycle all the time.