There will come a point in every athlete's career when he or she will realize that in order to improve, one must be able to properly reflect on the work that has previously been done. You must process what worked, what did not work, and at what frequency to be able to further make decisions down the road.
But what to keep track of? And how to keep that organized? Sure, you could go the approach that I utilized last year: the wondrous 300 page notebook. But that only works for reviewing stuff later, as you'll have whatever plan that you're trying to follow in some other place, as well as the data from your Garmin, or Timex, or whatever other training tool that you use.
TrainingPeaks, at its core, is a training log. But it's also a database of thousands of workouts, a data manager, a nutrition guide, a training plan...it is as much or as little as you plan to get out of it.
My coach, Doug, has used TrainingPeaks for a while for his athletes. He will generally build a certain time period worth of workouts out into the future. (So, the screen shot above? That's my current week's training. Yes, you get to see my mediocrity in person!) I, as an athlete, dutifully follow the plan and upload the data from my Garmin into TrainingPeaks. We then review the data generated to see how things are working out: is what we are doing helping? Is it reaching a level of toxicity where it would be better for me to rest? These are all things that allow us to work with one another.
By that end, TrainingPeaks is a dream. Because it allows us to be linked together, I get notifications when Doug has changed something within the plan. But I also gain the flexibility to move workouts around when life gets in the way. (Note: this is a Premium feature within TrainingPeaks, which requires a paid service membership. Basic accounts are more simple training logs, and there are free workouts, but no more than that.) Take, for example, this past week: I originally was supposed to have two workouts on Monday, a day off on Tuesday, and just a run on Wednesday.
Well, I woke up lethargic and stiff as all hell on Monday. Knowing myself, that swim and strength session would have been an unmitigated disaster. So I took that as a day off, planning to perform them Tuesday. Life got in the way on Tuesday, as Mrs. Crashing the Boards had a follow-up appointment and neurological exam. In other words, this was a "honey, you WILL be there with me, right?" moment.
So I swam and ran today. And I had the ability to drag and drop workouts throughout. Easy! Plus, with the added "post-workout" comments, it allows plenty of space to say what felt like it was working, and what wasn't.
Still, as with anything, TrainingPeaks isn't perfect. For the life of me, I can't get my Garmin to work with their Device Agent. This means that in order to get my Garmin file to attach into their system, I must first upload it to Garmin Connect. Then I export a GPX file out of Garmin Connect back onto my MacBook, and THEN I get the pleasure of uploading it into TrainingPeaks. It takes forever to do. Also, it is then quite slow to recognize the device file when trying to go back and look at it. (I find it far easier to just look at previous times using Garmin Connect, and then seeing the notes in another tab using TrainingPeaks.)
Another user-unfriendly note is that the layout leaves a fair bit to be desired. Although the calendar layout of the page gives you a good look at the workouts that are about to be done (or recently have been accomplished), it is difficult to access into the many workouts, Annual plans, etc. It almost seems like the page was optimized for mobile viewing, rather than on a physical computer.
Still, there's so much to like here. I love having the flexibility to move my workouts around as necessary to get them in; I love being able to have one home for all of my data (even if occasionally it leaves something to be desired); and I love being able to see all of the work that I've done in a single page view. You can keep track of meals, equipment, etc. How much did I eat? Why am I not at race-weight? Should I replace my shoes? All questions that you can use TrainingPeaks to answer.
Overall, it's in my opinion the only worthwhile method to keep track of your training, and even moreso if you are working with a coach. The days of an e-mailed schedule in a Google docs file are over.