The purpose of the track repeats is to improve max VO2 running speed and running economy. The maximum VO2 is a measure of the runner’s ability to produce energy aerobically. A runner with a higher VO2 max can run faster than a runner with a lower VO2 max. The speed intervals contribute to the “run faster” part of Run Less, Run Faster.
Track repeat workout for Tuesday, March 13th
I run the repeats on a treadmill, instead of an actual track. (Most schools don’t take kindly to strange adults on the track during school hours.) Before the workouts, using the charts in the book, I look up the designated time for each interval distance (400, 600, 800, 1000, 1200 or 1600 meters). I convert those times into both minutes-per-mile and miles-per-hour, so that I can set the treadmill to the appropriate speed for my intervals.
Based on my half marathon time from the 2011 Heart Mini Marathon, 2:04:16, RLRF predicts that I would run a 5K in 26:50 and that I should use the track repeat times associated with a 26:50 5K. I tried running the intervals at the suggested paces and nearly killed myself. Instead, I’m using the paces associated with a 28:00 5K (2:09:47 half and 4:32:28 full marathon):
400 meters in 2:05 = 8:22/mile = 7.2 mph
600 meters in 3:10 = 8:30/mile = 7.1 mph
800 meters in 4:14 = 8:31/mile = 7.0 mph
1000 meters in 5:20 = 8:35/mile = 7.0 mph
1200 meters in 6:28 = 8:40/mile = 6.9 mph
1600 meters in 8:45 = 8:48/mile = 6.8 mph
Using miles-per-hour on the treadmill isn’t perfect. The machine is only adjustable to one decimal point, so an 8:31 mile and an 8:35 mile are both done on the 7.0 mile-per-hour setting. However, it’s also difficult to hit exactly the right pace on a track, so I think the treadmill mph settings are close enough!
I always complete the 10 – 20 minute warm-up and the 10 minute cool-down, but I have yet to finish the main (5K) set as specified. Even using slower intervals than recommended, I tire quickly. I often slow the belt down or complete fewer intervals (or both). Still, I’m getting a good workout. My heart rate easily reaches the performance zone (91% of max) during the speed intervals. During the rest intervals, if I feel like I need more recovery, I walk until my heart just drops out of the aerobic zone and then start the next speed lap. I keep telling myself “just one more speed interval,” until I simply cannot complete any more and then I begin the cool-down. I aim to complete a total of at least 5 miles (including warm-up and cool-down).
Normally, the treadmill bores me, but I’m never bored running intervals. There is always something to look forward to (or dread) in the next segment. I feel like a total badass when I go from walking to a fast run, rapidly punching at the “increase speed” button. After my speed laps, I’m incredibly relieved to decrease the speed for my rest intervals. I’m usually 45 minutes into my workout before I realize how long it’s been.
I found this the most challenging, but the most rewarding, of the three key runs. I’m not a sprinter; I’m more of a “slow and steady” runner. The track repeats are very difficult to complete, but leave me feeling kind of awesome.
Sporty Sunday is a recurring feature in which I share my fitness routine and offer and solicit advice. While this content might seem a little out of place in an outfit diary, a healthy, strong body is the foundation of my wardrobe. I hope to inspire my readers to be fit as well as stylish!