Yeah man you can do it! My little one was 3 years old when I first did this. The secret is to just start with small manageable rep sets just beyond your comfort zone. Then utilise incremental change to increase them till you're at your maximum.
For me, waking up early is the key, in fact that is one of the disciplines which I forgot :-)
Good luck, you can do it!
RE: 30 Days Of Discipline - Day 2