What is Lactate Threshold?
Lactate threshold is the period during intense exercise when lactate starts to build up. During steady-state, sub-maximal exercise, your body uses predominantly aerobic energy systems that require oxygen. But as you increase the intensity, your body increasingly turns to anaerobic sources of fuel as more power-generating fast-twitch muscle fibers are activated.
When energy is produced anaerobically, it goes down an alternative pathway that produces lactate. At some point, as exercise intensity increases, lactate starts to accumulate since the liver can’t remove it fast enough. This causes a build-up of lactate and hydrogen ions and leads to fatigue. When you reach your lactate threshold, lactate has built up to the point where you have to slow down or stop because they’ve “hit the wall.”
Lactate Threshold Training
Fortunately, you can increase your lactate threshold through training. This means you’ll be able to work out at a higher intensity before becoming exhausted. Highly trained athletes may be able to work out at an intensity as high as 90 percent of their V02 max before reaching their lactate threshold, whereas a less fit athlete will reach their threshold at a lower percent of their V02 max, around 55 to 70%. Most elite athletes have increased their lactate threshold through training.
There are several ways to improve your lactate threshold. Doing so will give you the ability to exercise longer and harder before becoming fatigued. One way is to gradually increase the volume of the training you do by no more than 20% per week. If you increase training volume more quickly, you won’t give your body enough time to recover. Increasing the volume of your training helps mitochondria that produce energy aerobically become more efficient at doing so. This means you won’t build up lactate as quickly and become fatigued as rapidly when you do endurance exercise.
You can also improve your lactate threshold by increasing the intensity with which you do steady-state endurance workouts. This would involve working out at around your lactate threshold for 20 minutes or an intensity that’s equal to a rate of perceived exertion of 6 to 8. When you work out at this intensity, you build up some lactate and hydrogen ions, and your muscles adapt and become better at dealing with them and become more fatigue resistant. You only need to do this once or twice a week to get benefits.
Another way to increase your lactate threshold is to do high-intensity interval training. You can set up the intervals in a number of ways, but a work-to-rest ratio of between 5 and 1 to 7 and 1 is optimal for lactate threshold training. One way to do this is to work at an intensity that’s very hard but not your maximum effort for 10 minutes and then recover for 2 minutes. Repeat this sequence 3 or 4 times. Since this is a high-intensity workout, you shouldn’t spend more than 15% of your workout time doing it to allow yourself time to recover. It’s also best to start out with 1 or 2 intervals and gradually add more over time.
The Bottom Line?
Lactate threshold training can help you run or cycle harder and longer without becoming fatigued. Don’t do it every workout though. Your body needs time to rest and recover.
References:
The University of New Mexico. “Lactate Threshold Training”
On Fitness magazine. September/October 2011, pages 70-71.
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