Taking off the training wheels: Is there an optimal training intensity?

Defining the optimal training schedule

Let me start out by saying, despite our best attempts, research hasn’t been able to identify a singular optimal training regimen. Part of the difficulty lies in the fact that we are all unique, tolerate different types of exercises differently, we play various sports, and pursue our own events. Personalizing a training schedule based on all of these characteristics would incorporate too many variables to be practical!

So, what can we do? 

One option is to study the elite athletes, of course. However, this can be a difficult task, as well. How many of you think you could convince a world class athlete to try a few new approaches to their exercise routine to see if any of them are better or worse? Because of this, a majority of our studies are ‘restrospective’ or reviews of exercise regimens after-the-fact.

So, what’s the purpose of this article?

There’s plenty to be learned from the retrospective analyses mentioned above, improvements we have identified over time, and ways that we can help incorporate these training programs into our own lives. Afterall, not all of us may have the time, energy, or desire to work out the EXACT same way the pros do, but we can still take the information we have gleaned to make our own plans more efficient.

For the purpose of this article, I will be reviewing a fantastic analysis from a researcher and world-class athlete (Professor Thomas L. Stöggl) (1). Professor Stöggl is a champion Austrian cross-country skier, as well as a researcher with a focus on strength and endurance training, so his expertise comes from with both academic and personal experience!

So, what’s the summary?

In this article exercise/training intensity distributions were categorized among a few broader categories:

1. High volume low intensity exercise (HVLIT)

   • A large amount of training at low exertion (ie. Low to moderate heart rate elevation)

2. Threshold training

   • Training at your ‘lactate threshold’ (ie. Somewhere around your 10K to half marathon pace, not an all-out effort, but definitely pushing it!)

3. High-intensity training (HIT)

   • High intensity work (ie. almost max heart rate, think sprints)

4. Pyramidal 

   • A large base if low intensity work, a moderate amount of threshold work, and a small amount of HIT to top it off

5. Polarized

   • Large base of low intensity work and large amount of HIT work, with just a small amount of Threshold training in the center

A comparison of these studies (mostly through retrospective analysis, but with a few controlled studies) was able to yield some valuable information. For example, in evaluating exercise regimens among runners, performance seemed to improve with a higher emphasis on HIT training, rather than Threshold training. 

While it may seem obvious that training at higher intensities leads to more improvement, there was a limit to this effect: 

“The implementation of four HVLIT, one HIT, and one THR session over 4 weeks resulted in improved running speed at maximal oxygen uptake (VO2max) and running economy. A further 4 weeks intensification, including two HVLIT, three HIT, and one THR session each week, showed no additional performance benefit, but increased subjective muscle stress, reduced sleep quality, and increased plasma epinephrine, all indicators of impending overtraining.”(1)

What does this mean?

Essentially, we need to find a balance between stress on our bodies, the physical and mental toll of exercise, and the benefits (again both physical and mental!). Low intensity exercise can be easier on the body and lead to small improvements, but it is slower, takes longer to accomplish, and… based on athlete reports, can be more boring.

Adding in threshold and HIT work is more exciting! It can be more fun. But it is also grueling work that can’t be done every day.

Ultimately, this leads to a mixed approach being the best approach. Many elite athletes have traditionally followed a pyramidal scheme, but there is newer and mounting evidence to support a polarized approach as well.

Dr. Kraft’s recommendation:

Ultimately, we all need to listen to our bodies, to learn from them and adapt with them. 

Start with a solid foundation. We should all focus on a heavy base of lower intensity exercise, while mixing in some higher intensity work, as well. Aim for 50-70% of your work to be at lower intensities.

Use Athlytic to see what you’re ready for. If you’re having a rough day or if your recovery was low and your sleep was poor, take it easy that day. Take a recovery day and make it a low intensity training session.

Have some fun! Aim for 20-30% of your workload to come from some interval training or high intensity work. The rest of your workload should be either threshold or lower-intensity, higher volume.

In practice, this looks something like:

- 3 days of low-intensity, higher volume training

- 1 day of HIT

- 1 day of threshold training.

Be sure to take your rest days and add in some mobility and strength work to really round out the regimen. 

That said, if you only have time for 3 days per week, prioritize 1-2 of those sessions as low intensity, high volume, while keeping the third for the intervals work.

Feel free to read the article below for more information and amazing studies! Read on and train on!

Sources and Further Readings:

1. Stöggl TL, Sperlich B. The training intensity distribution among well-trained and elite endurance athletes. Front Physiol. 2015 Oct 27;6:295.