Podcast, Science and Physiology

Effects of block training with increased intensity or increased volume with Olli-Pekka Nuuttila | EP#327

 February 28, 2022

By  Bernardo Gonçalves


Olli-Pekka-Nuuttila - That Triathlon Show

Olli-Pekka Nuuttila is a doctoral researcher at the University of Jyväskylä. In this interview we discuss his recent study comparing two-week blocks of either increased volume (70% increase over baseline) or increased intensity (5 interval sessions per week), and how the findings can be applied in the real world.

In this Episode you'll learn about:

  • How does a two-week block of volume or intensity impact performance (3000m running time trial), subjective markers of recovery, and hormonal/biomarkers of recovery and stress?
  • The impact of adding a recovery week after a two-week focused block on volume or intensity
  • Individual variations in response and non-responders or trivial responses
  • When and how to incorporate volume blocks or intensity blocks in your training

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Olli-Pekka's background

04:10 -

  • I am a doctoral researcher at the University of Jyväskylä, and my research topics primarily related to endurance training and recovery monitoring. 
  • Currently, I am doing my PhD thesis. I have published three out of four papers and have already submitted my last one.
  • The goal is to finish my doctoral studies at the end of this year.

Previous research that led Olli to produce the studies on endurance training

05:58 -

  • I am interested in comparing the impacts of volume and intensity on recovery and training adaptation. 
  • With this research, we are trying to answer questions that previously did not have a solution.
  • There were not too many studies on this topic before that have compared these block types. Usually, they compare intensity maintaining the same volume, but they do not consider the ability to do higher volume at a lower intensity.
  • Therefore, this study's value shows a great contrast between these two approaches.
  • High-intensity block training has more research than low-intensity training. Thus, we expected to obtain better performance with the high-intensity block based on previous studies. However, we did not know what to expect from the low-intensity block.
  • Typically, if volume increases, there is an increase in low and high-intensity training. So, it was an unanswered question as well. (low-intensity training volume and its impact on performance)

Outcome performance measurements

08:36 -

  • A 3000m running performance test was the only performance test we did. We did it on an indoor track.
  • We measured heart rate variability, and on the testing days, we also accessed resting hormonal levels and nocturnal urine samples before testing regarding recovery metrics.
  • We recorded subjective recovery every day. The subjects would give us information on their readiness to train, fatigue, muscle soreness, stress and sleep quality.
  • During all training sessions, participants used heart rate monitors and GPS data.

Participants in the study

09:55 -

  • In the final analysis, we had 15 participants per group, and we had men and women in both groups. (9 men and six women)
  • They were recreational athletes, so they trained regularly.
  • The mean VO2max was about 50 mL/kg-min. 
  • The baseline 3000 m time was 12:30min. Men's baseline was around 11 min on the test.

Training blocks

11:29 -

  • We had a preparatory period of two weeks intending to analyse how participants regularly trained and ensure similar background for all our participants for our training period.
  • We advise them to continue their regular training concerning volume but control and limit the intensity. (train primarily below the first lactate threshold) However, they did an interval session during the two weeks preparatory phase.
  • The interval session was 6x3min with 2min of rest at the maximal sustainable effort. Therefore, there was no indication of heart rate or pace. The only goal was to maintain a consistent intensity throughout each set.
  • The intensity group did ten sessions like the one they did on the preparatory session during the study period. (two weeks)
  • If participants regularly did more than five sessions per week, they would also incorporate them during the study period. These sessions were primarily easy or active recovery sessions.
  • However, all participants had at least one rest day.
  • The volume group increased their training volume from the baseline by 70 %, and they also had those supervised short and long training sessions. 
  • These long training sessions averaged around 20 km. And shorter sessions were 13 km.
  • We did four performance tests in total. There was a control test before the preparatory period. Then, we did another baseline test before the study period.
  • There was a recovery week after the study period.
  • Immediately after finishing the training period, we did a rest day and a test the next day. 
  • The final test was after the recovery week.

Recovery week

16:17 -

  • We reduced training to 50 % of the baseline.
  • Both recovery weeks were similar in both groups with only low-intensity training.

Results of the study

16:50 -

  • Both groups improved their 3000 m performance immediately after the block, and there was no difference between the groups.
  • The results were surprisingly similar. However, in the article, it is interesting to look at the differences between athletes.
  • More athletes have a minor performance improvement if we look at each athlete in the volume group. (non-responders to the training block)
  • In the interval group, you might have two non-responders, but the rest improved significantly.
  • After the recovery week, there was no significant difference between results comparing test results immediately after the training period and after the recovery week.
  • However, peak performance was better after the recovery week than the baseline.
  • The results show a time reduction of -2.5 % in the interval group and -2.2 % in the volume group. (19 s and 17 s improvement in the 3000 m)
  • We expected an increase in fatigue based on previous studies concerning subjective markers. 
  • The readiness to train combines multiple aspects like how mentally and physically you feel to train. 
  • The most significant changes were muscle soreness, which increased only in the interval group.
  • Muscle soreness did not increase in the volume group and even decreased during the recovery week, so the differences were significant.
  • The most interesting hormonal findings were the changes in norepinephrine that remained elevated even after the recovery week for the interval group. 
  • It seems that it may take more time to recover from high-intensity training.
  • There was no change in norepinephrine or any hormones in the volume group.

Conclusions for endurance athletes

22:07 -

  • First, I was surprised by how recreational athletes tolerated these training blocks.
  • If we talked about high-performance athletes, they would tolerate it even better.
  • It seems that these blocks can be an effective method for improving performance fast.
  • You can do this type of interval training throughout the training season. In other studies, we had seven-day microcycles with positive results in performance, and they decreased the likelihood of getting those negative responses to training.
  • On the other hand, athletes tolerated high volume training better. Therefore, it might be possible to do even more extended volume periods than we did in the study.
  • Concerning individual responses, if I have to choose between these two groups and the primary target is to improve maximal performance, it looks like interval training is more likely to improve performance substantially.
  • Some athletes had impaired performance after the recovery week in the interval group because of fatigue.

The impact of the recovery week on performance

26:48 -

  • One reason for some strange responses to the recovery week was that some athletes might need some interval sessions during the recovery week.
  • Typically, you want to maintain intensity in the taper week, despite the reduction in volume.
  • Therefore, athletes could detrain from the recovery week, especially for the high-intensity group.
  • Most impaired athletes were high responders in the immediate post-training tests to manage training better and keep doing it.

Tips for coaches and athletes

28:39 -

  • I do not think I would do these very focused blocks with only low-intensity or high-intensity training.
  • However, there are no studies on these blocks would work long term.
  • There is only a case study from cycling where they did a low-intensity block during one year and high-intensity blocks during the other year.
  • Those results were fascinating, so studying how alternating these blocks could impact performance.
  • However, I believe interval blocks help peak and achieve maximum performance.
  • Training camps would be opportunities to do those low-intensity high-volume training blocks.

Other studies Olli worked on during his PhD

31:39 -

  • The first article compared different types of endurance training sessions on recovery.
  • We did long, low-intensity and moderate and high-intensity treadmill sessions.
  • We measured countermovement jumps, heart-rate variability, and other parameters. (immediately after training and 24 h after a submaximal running test)
  • Moderate and high-intensity sessions would most decrease HRV but not impair neuromuscular performance.
  • The neuromuscular performance was lower after the long-distance supramaximal intervals. However, HRV remained higher compared to the other training types.
  • Another finding was that submaximal heart rate decreased after all sessions, and after 24h, RPE remained elevated.
  • It reminds us that heart rate is not a good monitor of recovery.
  • It would help if you used RPE to run at a specific speed or make changes in your training sessions.
  • The final article I will be publishing applies the information gathered from previous studies. It focuses on individualised training prescription, similar to HRV guided training sessions.

Tips and advice for endurance athletes that want to improve their performance

36:02 -

  • First, endurance training consistency is the essential factor to improving performance for any level of athletes.
  • No matter what training typology you use, consistency will improve performance. In my studies, the improvements were similar with increasing volume or intensity.
  • If you keep training with high-quality, you will get rewarded for that work.
  • Moreover, you should not rely on only one marker to access recovery. Instead, it would help to have a broader view of your perceived recovery and how your training is going.
  • HRV is a good marker, and it has a clear advantage when combined with other markers.

Rapid fire questions

38:06 -

What is your favourite book, blog or resource?

Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance by Alex Hutchinson 

What is an important habit that benefited athletically, professionally or personally?

Consistent endurance training is for my help for my physical and mental well-being.

Who is someone you have looked up to or who has inspired you?

Professionally, Stephen Seiler has done impressive work in the academic sports area. When I was a junior athlete, Mika Kristian Myllylä was my inspiration.


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

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