PUBLISHED 01/30/2004
You can use any of the following four ways to determine your lactate threshold, and, consequently, your tempo-run pace:
1. Perceived effort. In general, your perceived effort is how hard you feel you're working when you're running. For a tempo run, your perceived effort should be "comfortably hard." I know that sounds like an oxymoron, same as "jumbo shrimp." How can something be comfortable and hard at the same time? Yet that's exactly what tempo-run pace should feel like. You're running fast enough so that you know you're working hard, but if you had to, you could keep up the pace for up to an hour. If you're on a tempo run with a training partner, you're able to say a few words here and there, but you can't deliver a lengthy diatribe. For that reason, I suggest a tempo run with your boss.
2. Heart rate. Although heart rate at lactate threshold varies from person to person, it usually falls between 85 to 95 percent of your maximum (women are often on the higher end). Experts in the field of exercise science have come up with an equation to help you calculate percentages of maximum heart rate. Plug in your own numbers below to calculate 85 percent of your maximum heart rate:
205 - half your age - resting heart rate x .85 + resting heart rate
So, if I admitted to being 40, and had a resting heart rate of 50 (measured first thing in the morning before getting out of bed), then I'd be crunching these numbers: 205 - 20 - 50 = 135 x .85 = 115 + 50, which equals roughly 165 beats per minute.
Once you know your tempo heart-rate range, strap on a heart-rate monitor as you head out the door, and it'll tell you if you're hitting your range. If you don't run with a heart-rate monitor, you'll need to keep track of your heart rate yourself. Halfway through your tempo run, slow down for a brief walk and find your pulse. Count the beats for 10 seconds, and multiply that number by 6 to see if you're in your tempo range. Then get right back to your workout.
3. Respiration rate. When you hit your lactate threshold, your breathing intensity also increases. Most runners breathe in a rhythm that coincides with their stride rate. The breathing patterns of three to three (taking three strides while you breathe in and three strides while you breathe out), and two to two are most common for easy running. But when you hit two to one (two strides while you breathe in and one stride while you breathe out), you're cruising in tempo land.
4. Racing pace. You can base your tempo pace on either your 10-K or your 5-K race pace. Shoot for about 20 seconds per mile slower than 10-K pace or 30 seconds per mile slower than 5-K pace. --E.E.
