This week appears to be similar to the first week of skill building. Running and swimming are typically the hardest for novices. Running, because it takes so much more cardio and bone strength than day-to-day activities. Swimming, because its typically the least comfortable of the three for us land-dwellers!
Regardless, each workout is still designed to be low intensity, which fairs well for my long runs. Long runs should always be done at an "easy" pace. The running "long run" is designed solely to build endurance to increase distances safely. So, again, I'm good here.