The benefits of having a personal health and fitness journal outweigh the time it takes to write to it every day. It's your choice weather your journal is detailed to the extreme with every calorie you eat, or very basic with just and overview of the day.

I personally chose more of a basic journal which I have posted here. The journal includes if I have been eating healthy throughout the day, what kind of exercising I've been doing, and perhaps my plans for tomorrow. Not only will this keep your mind motivated to continue your fitness goals, just imagine how much you haven't been doing since starting the journal.

The journal can work subconsciously for you. Since you are writing down your days events, you will be much more inclined to do more throughout the day so you will have more to write in the journal.
You will know the less good stuff in the journal you read, the less your body is working towards health and fitness.

This lets your brain go over all your past workouts as well, even if they are just as basic as saying
"
July 5th: Upper body weights, ran mile, 50 X 2 sit ups, ate healthy.
"
That journal entry isn't detailed at all but you can obviously go back later on and read it and be like wow, I accomplished something that day, now I need to do at least that if not more today.

Having a more detailed journal with exactly how much food you ate and how much activity you've done is very cool and encouraged, but if you don't think you have an hour a day to write to it don't sacrifice not writing to a journal when you can spend 2 minutes a day writing to a simple one.

An example of my journal entry is below, which takes less than 2 minutes a day to write and was starting in Microsoft notepad. This journal entry started when I was on a 5 day juice fast.

sun 13th 07-13-2008 Fast all day, juice
haul tile up stairs, didn't do much else.

Mon 14th Fast, pool swim, 2 mile walk,
2x 22 body weight squats
2x 16 pushups
2 x 50 crunch
stretching

Tue 15th Fast, 1 mile jog 3-4 x sprint run
house cleaning
fresh juice with juicer, cheated half a scoop of protien powder

16th. Tile job, stairs, work hard, apple at night

17th juice all day, apple and salad at night. salad with cucumber and olive oil
and vinegar tastes like nuts right now. so delecious