Variable Intensity in Marathon Training

Many athletes have a tendency to work out at an intensity where you feel like you are actually getting a workout, but are not going so hard that you can’t keep up your pace. And they only train at this intensity. But studies have shown that this method backfires when it comes to improving race performance in the long term as you do not recover sufficiently and you did not train your body to perform at higher intensity

Since the early 2000s, there has been quite a bit of research done on the best ratio of high vs low intensity exercise, which has benefited professional athletes and can now benefit you as you train. The research basically boils down to this: the 80/20 rule.

The 80/20 rule is simple: 80 percent of your training is done at lower intensity and just 20 percent is done at higher intensity.

Here’s why it works

The lactate threshold is the point at which lactic acid builds too rapidly in the blood, and the body cannot process it fast enough due to exertion. This no man land, and it tends to fall in the moderate to moderately-high intensity range for most athletes. By spending more time at lower intensity, below even the ventilation threshold, it is less stressful to the nervous system than simply training below the lactate threshold.

Training harder than the ventilation threshold stresses the nervous system (which is why you feel like you’ve had a workout) and by spending just 20 percent of your workout time at this higher intensity, you will actually be setting yourself up for greater success when race time comes.

The first step to success with the 80/20 rule is planning

You need to plan to do 80 percent of your training at low intensity. But this is harder than you might think because of something called “intensity blindness,” which basically means that when you think you are going at low intensity, you are really already at intermediate intensity.

It may feel strange at first to dial back to the point of meeting the low intensity threshold. Understand that when you kick it up for the 20 percent, you will cover equal distance in less time. But you should count the entire time spent with elevated heart rate, including active recoveries.

You will soon notice you are more comfortable with your low intensity training and will perform better in your high intensity training. Your fitness level and race times will benefit from following the 80/20 rule and you will never go back to your old habits.