Hey Steve,
Sounds like you're doing great so far! My husband and I both work out a lot too and my advice to you is to listen to your body. It will let you know if/when the time comes that you just need to rest. When my husband Ron was going through the radiation he was fine until going into the fourth week. Just remember, your body is going through a lot right now and will need rest in order to heal. Don't push yourself too hard.
All the best,
Shelley