Sweet enola gay, son - the seventh day you must rest, for otherwise you'll burn up and explode into 1,000,000 glass shards.

Short answer: yes.

Longer answer: yes, but if you're feeling tired and/or lacking energy, pay attention to your diet and sleep routines - you'll get used to any muscle groups needing conditioning in due time. Your body is a lot stronger than your mind allows you to think, you'll be able to ride no problem.

I use my bike for my transportation, beit to work, friends or wherever - it may seem like a massive step, but you'll get used to it as part of your daily routine and it just becomes normal.

IOW: Just ride, it's not like you're entering the TdF.