Originally Posted by DannoXYZ
While the 2x20 is a tempo workout right at or just below LT. This will improve LT and aerobic capacity, but not work the muscles like in the 6x6. You want to incorporate both workouts in your training regimen.
Am I correct in assuming that, done properly, you need a recovery day after doing these intervals? And if so, do you do these each once/week? That's 4 days out of your week right off the bat. Or do you do them less frequently?