I use Runningahead.com for my training journal.
The online journals/trackers can be fun and motivating (if you compare yourself to others on the site)...or you complete against yourself from week to week, month to month, etc. But I found myself getting lazy about keeping the journal updated.
I basically download my Garmin watch data to the Garmin app. on the HD...then I update my Excel spreadsheet with my daily workout mileages to track the number of miles on my running shoes...to help me know when the mileage is getting high...and I need to purchase & switch to new shoes.
Of course these two methods don't do as much as the online journals...since they will do a lot of additional calculations for you...like average paces, fastest pace, most miles, etc.
Finally got around to uploading GPS data from my watch. For the first 9 months of this year I only averaged 5-6 miles per week.
So far for the last four weeks I'm averaging close to 15 miles per week, big improvement.
Very nice. With what you've been running lately...I'm betting that average weekly mileage may creep upwards a bit!
Honestly, at this stage of my life, don't see increasing my weekly mileage a whole lot. Will probably top out in the 20s per week.
Different folks...different goals.
10 years from now when I'm closer to your current age...I expect to be doing the same amount of miles as I am now. Probably slower (hopefully not too much).
Of course all of this depends on the wheels no falling off the wagon!
-Nick
p.s. I had a pretty good workout yesterday...hopefully a good one today as well.
Although I feel a cold coming on (which I hope to kick it's butt). I ran a shortened workout in 39°F temps on Thursday during a sleet storm (10 miles...wanted to do 12). I got home completely soaked to the bone...and very very cold (nothing worse that being soaked to the bone & chilled). I'm talking just a long sleeved t-shirt, shorts, hat, and gloves)...which is what I normally wear in those temps.
It was dry/cloudy when I started. I got stuck in the storm while out on the route. Stuff happens!