10-20-30 interval training, which involves intervals of low, moderate and high intensity, has been shown to be an effective way to improve running performance and overall health. It can, however, prove to be a bit uncomfortable for some people, as the 10-second interval involves an all-out sprint at maximum intensity, but a new study suggests that this kind of training can be just as effective if the sprints are run at 80% of max. Given this less-stringent requirement, researchers hope that the new knowledge will encourage more people to adopt a form of 10-20-30 training, which benefits both blood pressure and cholesterol levels.

The Study

Nineteen male runners in their 20s and 30s replaced their regular training with 10-20-30 workouts, which consisted of three to four five-minute blocks, three times a week for six weeks. One group performed the 10-second sprint with maximum effort (the "fast" group) and the other with approximately 80% of their maximal effort (the "slow" group).

Over the 5K distance that the researchers tested the 19 runners on, the “slow” group (who sprinted at 80% of their max) achieved an average improvement in their running time of 42 seconds compared to their original time prior to the six-week interval training. Meanwhile, runners in the “fast” group only shaved an average of 24 seconds off their times. Both groups of runners improved their overall fitness (maximum oxygen uptake) by 7%.

“The result of the study really came as a surprise,” says Jens Bangsbo, PhD, of the University of Copenhagen’s Department of Nutrition, Exercise and Sports and lead author of the study. “We think that it is related to the fact that training at 80% of one’s maximum still gets the heart rate up significantly higher than a runner’s typical training. A higher heart rate leads to improvements in heart function and circulation, as evidenced in their times and fitness levels.”

Maximum Effort Still Yields Maximum Result

At first glance, it appears as if holding back somewhat on one’s final sprint carries nothing but advantages. However, as the researchers dug deeper to better understand how the runners’ muscles reacted to the two loads, one important difference emerged.

“Only the max group formed more mitochondria, which are the tiny power plants within our cells,” explains Dr. Bangsbo. “They are important for muscular endurance and the ability of our muscles to engage in long-term work. So, if you plan on running a half or full marathon, you’ll need to sprint at 100% to achieve the maximum benefit.”

In other words, submaximal training is enough to improve performance in shorter races, but longer races likely require more of an all-out effort.

What the Research Means to Health and Exercise Professionals

While this research focused on runners, 10-20-30 interval training, like other forms of high-intensity interval training, comes with a wide range of other health benefits. An earlier study, also by Dr. Bangsbo and colleagues, showed that individuals with type 2 diabetes who performed 10 weeks of 10-20-30 training lowered their blood sugar and reduced their amount of visceral fat, which surrounds important internal organs like the liver, pancreas and intestines and is associated with a higher risk of health conditions such as heart disease and type 2 diabetes. This is good news of all your clients, runners and non-runners alike.

“Just as with other high-intensity exercises that elevate heart rate, 10-20-30 workouts have a positive effect on health,” states Dr. Bangsbo. “Among other things, we also see improvements in blood pressure and cholesterol levels. At the same time, interval training is more efficient, because you can get into better shape and improve your health in less time than by running at a constant pace.”

Dr. Bangsbo also believes that this type of training can feel both easier and more fun. “Many people find that interval running is more fun due to the changes in pace. With this study, we’ve shown that, even if you ‘only’ run at 80% during the sprint, it is still a very effective form of training, which may encourage even more people to opt for this kind of training.”

By now you’re probably convinced that your clients could benefit from this type of training, so here’s how it works: As mentioned earlier, 10-20-30 workout training involves intervals of low, moderate and high intensity. The numbers refer to the time in seconds spent on each part of the interval; although it is commonly known as 10-20-30 training, the intervals are actually performed in reverse order (30-20-10). Here’s how it typically breaks down:

• 30 seconds of low-intensity effort: The first part of the interval is performed at the lowest intensity (~30% of maximal speed). This could be a slow jog or even a walk, depending on the individual’s fitness level.
• 20 seconds of moderate-intensity effort: The low-intensity burst transitions to a more moderate pace (40-50% of maximal speed). This is challenging but not as intense as the final phase. In running, this would be a brisk jog.
• 10 seconds of high-intensity effort: This is the most strenuous part of the interval because it involves maximal or near-maximal effort (74 to 84% of maximal speed). In running, for example, this would mean a sprint.

The entire cycle (30 seconds low, 20 seconds moderate, 10 seconds high) is typically repeated for a set duration, often five minutes (1 round), followed by a rest period (approximately 2 to 3 minutes) and then repeated for set number of rounds. This cycle can be repeated several times, depending on the overall length and intensity of the workout.

This type of training is popular because it can be adapted to a wide range of activities, not just running. It’s also efficient, as it allows for a significant amount of work in a short period, and it can be effective for improving both aerobic and anaerobic fitness.

Beginners should start with a 1 x 5-minute training (1 round), while those who run regularly might start with 2 x 5-minute periods (2 rounds) with a 2- to 3-minute break in between rounds. As a client becomes accustomed to this type of training, they can increase their speed during the 20- and 10-second intervals, as well as gradually increase the number of 5-minute rounds and reduce recovery time.

To achieve the most benefits, this type of training should be performed at least twice per week. Beginners should not run more than twice a week at first. Recreational runners can run three times a week, while experienced runners, who may already be accustomed to interval running, can choose to replace up to four training sessions a week with 10-20-30 training for optimal effect.

As a health and exercise professional, the 10-20-30 method can be a useful tool to create varied, high-intensity interval training sessions for clients of different fitness levels. As always, it’s important to tailor the workout to the individual’s capabilities and goals, and to ensure proper warm-up and cool-down to prevent injuries.