Observe your VDOT

While most cursory web searches for the term 'VDOT' returns pages for the Vermont and Virginia Departments of Transportation (side note—Vermont does better in terms of environmental impact: they have fewer paved roads, but Virginia takes the prize in terms of road maintenance: on many long rides around Charlottesville in the past two years, I have been amazed at the quality of third tier country roads), you'll find an athletic training gem slipped in among the bueracratic sites: RunBayou's VDOT calculator. VDOT is Jack Daniels' (the running coach, not the distiller) modified VO2 max term, and it can be used to predict your training performance. Better yet, it can give you the times at which you should run your intervals. Run below your VDOT and you don't improve; run above your VDOT and you risk injury. It sounds simple and, happily, it is simple.

For example, I ran a 1:20 half-marathon earlier this year in Portland (not great, but I went out fast, Ryan Hall style, with the front runners, and blew up a little bit). Using Jack Daniel's VDOT tables, I found a value of 58, which feels a bit low for my cycling VO2 max but is probably in the ballpark for my running. Daniels' tables, though, don't offer the level of specificity some of us desire. Enter Runbayou.com, which lets you enter a race performance (note that this figure is an actual performance, not a goal) and then breaks down your interval numbers in fine detail. Entering my 1:20 1/2 marathon time, I get the following results:

VDOT=58 (good, consistency)
Easy Pace (25% of my weekly training): 7:34/mile
Marathon Pace (about 35-40% of my weekly training): 6:25/mile
Threshold Pace (about 12% of my weekly training): 6:00—6:04/mile, depending on whether I'm doing shorter intervals (400s, 800s) or longer intervals (1200s, 1600s).
Interval Pace (about 8% of my weekly training): 1:23 400s; 3:28 1000s; 4:10 1200s.
Repetition Pace (about 5% of my weekly training): :37 200s; 1:17 400s.

The page nicely warns you about running above your VDOT, saying that you'll hurt yourself. The proof is always in the soup, however, and on Tuesday I ran 12x200, aiming for that 37' mark. Too bad I ran with a runner above my abilities, and most of our intervals came in around 35'. Yesterday my quads hurt; today they are full of the mythical cobra poison that endurance athletes learn to love and hate. I went for a recovery trot this morning and could barely manage to keep one leg moving in front of the other. The lesson?

Observe your VDOT.