Polarized Training - Study Analysis – Part 2
Part two of our polarized training study analysis explores a study conducted in Italy, analyzing 12 well trained male runners. This study compares endurance gains between two groups of runners who are either training with more zone one or more zone two training time, with both groups doing the same amount of zone 3 and higher intensity efforts. So, lets dive in and break it all down. You can find part 1 of the polarized training study analysis here - Polarized Training - Study Analysis – Part 1.
Polarized Training Study Review #2
IMPACT OF TRAINING INTENSITY DISTRIBUTION ON PERFORMANCE IN ENDURANCE ATHLETES – ESTEVE-LANAO, J., FOSTER, C., SEILER, S., LUCIA, A. 2007. (https://journals.lww.com/nsca-jscr/Abstract/2007/08000/IMPACT_OF_TRAINING_INTENSITY_DISTRIBUTION_ON.48.aspx)
The Good
There is a lot to like about this study, including the participants, testing methods and training program. All participants were well trained runners who had personal record 10K times in the 35-minute range. The study started with 20 people and ended with 12 subjects that completed with around 98% overall compliance. The group of 12 was split into two groups, with both groups having statistical values in similar ranges, such as a VO2 max, weight, height, and heart rate max numbers.
Both groups used the same coach and coaching methods, along with the same amount of strength training, higher intensity training (Above zone 3 for this study) and the same testing method for determining improvements.
The length of the study was 21 weeks, with an initial three-week preparation period all runners completed in the same way. The length of this study is its most valuable attribute. Most scientific studies are short, weeks in length and leave many questions about whether, if the type of training was to continue, what would happen? With the study being five months long, it provides a solid view of how aerobic adaptations are made.
Critical Analysis
The main objective of this study was to see a comparison between training in zone one or two under the same training load for runners. The results of the study showed both groups improving in the 10K run test with the Z1 group improving, on average, 35 seconds faster than the Z2 group. A 35 second lead in a 37-minute race can be considered significant, but within this study, the Z1 group was 22 seconds faster than the Z2 group for the initial 10.4 Km baseline run test. So, while the results are significant, it is fair to raise the question of the strength of the Z1 group in terms of genetic potential, focus and skill compared to the Z2 group.
Pre-Study Test Results, including the initial 10.4 KM results highlighted in seconds.
ESTEVE-LANAO, J., FOSTER, C., SEILER, S., LUCIA, A. 2007. (1)
Post Study Results between the Z1 and Z2 groups in seconds. Results - Z1 group improved by 2 minutes 37 seconds and the Z2 group improved by 2 minutes 2 seconds.
ESTEVE-LANAO, J., FOSTER, C., SEILER, S., LUCIA, A. 2007. (1)
With both groups, the main difference is that the Z1 group performed a ratio of 80 % zone one to 10% zone two work, compared to the Z2 group who completed 65% in zone one and 25% of the time in zone two. Each group of six runners both completed two hard sessions a week, such as intervals higher than zone three and one to two strength training sessions per week. Each group also performed an identical amount (10% of training) of zone three training sessions.
To achieve the same amount of training stress, the Z1 group trained 1.5 hours more a week, on average, than the Z2 group. The Z1 group was averaging 5.9 hours a week compared to the Z2 group averaging 4.4 hours. The Z1 group trained around 13 hours more over the study period compared to the Z2 group, which is an additional two weeks of average training hours. So as a challenge to this study, could simply more training result in a slightly faster 10.4 Km run time? There really is no such thing as an easy run, so while running in zone one is easier and at a slower pace, the bones and muscles in the legs, hips and spine take the body’s load on every stride, making an easy run an impactful run. Therefore, when you combine more training volume with the group that is initially faster, it brings to question the benefit of genetic and talent factors when it comes to analyzing study results.
Running in zone one is in no way the same as cycling in zone one. Spinning on the bike in zone one takes far less muscle force than a run workout in zone one and to be fair, is way easier. So, while this study shows improvements in running time over a five-month period, it should not be used in the same way to assess how cycling training happens.
This study shows exactly what type of training adaptations are made when you combine hard interval sessions weekly with zone one and two training for runners. To be fair with the study results, the Z2 group showed strength gains too, with a two-minute improvement in the 10.4 Km run test. A two-minute gain with the Z2 group, who initially tested slower than the Z1 group, is still a significant gain.
The study mentions the impact of factoring in more zone three training into the study and in agreement with the authors, more zone 3 running intensity (Referred to as lactate Threshold training in the study, which is technically accurate) and less zone one and two training would over train a runner, leading to overuse injury and more. This is because running is intense and far more intense than cycling. The science is the same as far as energy systems targeted, it’s just that runners can’t handle the amount of intensity a cyclist can. A cyclist can work at higher intensities more often because it is less impactful to the bones and muscles of the body. A cyclist needs to work harder because cycling is less impactful. So, while studies like this are good, the results should be taken honestly and focused solely on runners.
Mike Schultz, CSCS
References -
1 – ESTEVE-LANAO, J., FOSTER, C., SEILER, S., LUCIA, A. IMPACT OF TRAINING INTENSITY DISTRIBUTION ON PERFORMANCE IN ENDURANCE ATHLETES. Journal of Strength and Conditioning Research. 21(3), 943–949. 2007