Hypothetically........why couldn't you train everyday? If you split your routine so that each muscle group was worked witha minimum of 3-4 days rest, why couldn't one train everyday and achieve great results? Esp. if you get enough sleep, sit in an office all day and eat, and then train in the evening? Isnt that considered"rest"??
Something like
quads
chest/bis
hamstrings
delts/tris
quads
back/trps
arms
hamstrings,....so on...