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Is Polarized Training the Best for Endurance Performance? | #34 ft. Dr. Billy Sperlich

Updated: Feb 28


In this episode, Dr. Billy Sperlich and I discuss training intensity distributions and the use of wearables in endurance sports. He shares his background in exercise physiology and his interest in triathlon. Dr. Sperlich explains the challenges of defining training intensity distribution and the limitations of research in this area. He highlights the importance of individualization and regularly testing and adjusting training intensity zones. We define pyramidal training intensity distribution and the misconceptions and practical implications of polarized training.

Paper: The proportional distribution of training by elite endurance athletes at different intensities during different phases of the season -


1) Choose a quantification method for training intensity and stick with it for consistent results.

2) Consider the impact of culture and mentality on sports performance, as different countries have different sporting traditions and values.

3) Use wearables to monitor training, but be aware of the limitations and choose the right technology for your training model.

4) Identify key elements in your training model and evaluate their effectiveness to make informed adjustments.

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00:00 Introduction

01:28 Guest Introduction

02:25 Dr. Sperlich's Background and Interest in Exercise Physiology

03:25 Transition to Triathlon

04:43 Interest in Combining Different Disciplines

06:08 Interest in Nutrition and Heat Regulation

07:34 Involvement in High Altitude and Other Specialized Fields

08:32 German Training Science Tradition and High Volume Training

09:02 Early Interest in High Intensity Interval Training

10:30 Challenges and Misconceptions of High Intensity Interval Training

11:21 Research on High Intensity Interval Training in Children

12:16 Shift in Training Philosophy and Polarized Training

13:13 Calibrating Training Intensity Distribution

14:27 Comparison of Training Intensity Distributions

15:49 Definition of Training Intensity Zones

16:49 Different Intensity Clustering in Different Sports

18:12 Challenges in Defining Training Intensity Zones

19:42 Quantifying Training Intensity Distribution

20:39 Training Intensity Distribution in Endurance Sports

21:34 Differences in Training Volume in Different Sports

22:30 Challenges in Comparing Different Types of Exercises

23:23 Quantification Methods for Training Intensity

27:07 Impact of Culture and Mentality on Training Intensity

31:48 Importance of Training History in Defining Training Intensity

33:14 Training Intensity Distribution in Cross-Country Skiing

34:08 Variation in Training Intensity Distribution

35:29 Importance of Zone 1 Training for Runners

39:14 Polarized Training in Cross-Country Skiers

41:30 Shift in Training Intensity Distribution during Competition Phase

43:52 Limitations of Single Case Studies and Cross-Country Skiing Bias

46:14 Variability in Training Intensity Distribution

50:32 Importance of Considering Sport-Specific Training Intensity Distribution

53:00 Impact of Culture and Mentality on Training Intensity

59:05 Differences in the Repeat VO2 Max Study

59:33 Using Wearables to Inform Training

01:00:31 Choosing a Training Model

01:01:55 Types of Wearables for Training

01:03:23 The 24-Hour Training Approach

01:04:48 Measuring Sleep Quality with Wearables

01:05:44 Identifying Technology for Training

01:07:10 Key Elements for Successful Training

01:08:39 Considering Biological and Measurement Variability

01:09:38 Where to Find Dr. Sperlich

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