The most productive training isn’t always about going all-out. Here’s how you can get 100 percent from your 95 percent effort. These guidelines will help you improve your body’s ability to clear lactate and sustainable aerobic power.
Figure out your 100 percent (your lactate threshold)
If you try to train at 95 percent of a lactate threshold (LT) number that you’ve estimated to be too high, you will not be training at the optimal intensity. The best way to find your threshold is in the lab. If you can’t do that, you can use a 20-minute time trial effort to estimate your LT. Remember to take 90-95 percent of that wattage figure, which is still a very rough ballpark LT. Avoid using data from races or your best 20-minute effort. Both tend to be inflated.
Go longer to improve lactate clearance
Rob Pickels, physiologist for Pearl Izumi, believes that intervals as long as five minutes still target the VO2 max system and should be done as hard as possible. Sub-threshold work should be longer: efforts of 10 minutes or more are a good target, with a total of 45 minutes at sub-threshold intensity. Sustained climbs are great.
Focus on sustainability
If you like every workout to kill you, then get used to sub-threshold work feeling too easy. One way to tell what’s right is to do several 10-minute intervals. If your power is declining while your heart rate keeps rising, you’re going too hard. Train at a wattage and heart rate that’s relatively sustainable across all intervals.
Don’t obsess about the LT number. Train at 90-95 percent consistently and you’ll see the numbers rise over time. Think of it like weightlifting: if you wanted to curl 50 pounds, you wouldn’t pick up a 50-pound dumbbell immediately. You’d find the weight that maximally stressed your biceps — maybe just 20 pounds to start — and build from there.
Sub-threshold work can be done more frequently
No one can do VO2 max efforts day after day. But sub-threshold work doesn’t produce the same strain as a high-intensity effort, so it can be done several days in a row. To further maximize adaptation, you must periodically fatigue yourself with big training loads performed over four to five days. Sub-threshold work should be a hallmark of these so-called fatigue weeks when you are trying to accumulate large amounts of work in a short amount of time.
Don’t overdo it
Just because sub-threshold workouts produce low sympathetic strain doesn’t mean you can’t overtrain by doing them. Do only as much as you can recover from, particularly at the start of the season when fitness is low. Pros dedicate about 10-20 percent of their total training to sub-threshold work.
Listen to a recent Fast Talk podcast about why we should stop using the term “lactic acid:”