2x20s

Pronounced "two by twenties". So, what's so great about 2x20's? Well, if you're NOT doing these intervals you're probably NOT taking advantage of one of the best indoor/outdoor workouts for increasing Functional Threshold Power...especially if you do them at Level 4. I wouldn't recommend doing them without working up to them first. Either do 2x10s at L4 first or do the 2x20s at the Sweetspot Training Levels until you get in better shape. Here's what the profile should look like if you do them on the road. Notice that the first 20 minute interval was done just below my LTHR of 175 bpm. Also notice the Heart Rate creep...which is normal. The 2nd 20 minute interval exceeded my LTHR. Couple of things you shouldn't do..that you can see here: 1) do NOT take a 45 minute break between intervals like I did..that's WAY too much. However, to come to my defense, I stopped to grab a drink and ended up talking to a friend. And, 2) Don't let the Power on the 2nd interval drop more than 5% of the first. I was close on the second interval. BTW, if you do them inside, expect at least a 10% reduction in FTP power. Have fun!