Case study of a Japanese professional marathon runner (2h 10' PR)

This blog and case study was written by Fuminori Takayama. Fuminori is a Certified Strength and Conditioning Specialist with the National Strength and Conditioning Association and has a Ph.D. in Health and Sport Sciences. 

He has co-authored research publications that includes case studies of HRV conditioning for elite middle-distance runners and a review of conditioning using HRV.

If you have any questions, comments, or inquiries, please contact Fuminori here.

This work was partially supported by the research grant from Japanese Society for Running.

Profile of Asuka Tanaka

Born in 1989 in Fukuoka, Japan. His career as a long-distance runner began in junior high school. He had competed in several famous Japanese University Ekiden races (e.g., Hakone Ekiden). After a career in several corporate running teams, he is currently working as a professional runner, aiming to compete in the Paris Olympics. His personal record for a full marathon is 2:10:13.

Twitter: @asuka8675

Data collection

The data shown below was collected with an Oura ring, hence it is night HRV, and then read in HRV4Training and analyzed in HRV4Training Pro in the long term.

Heart rate variability during the past season

Below we can see some valuable data about Asuka Tanaka from May to November 2022.
He is a Japanese professional runner with a marathon personal record of 2:10:13. He is currently running independently, not on a corporate running team— typical of professional runners in Japan.

​As shown in box 1, he broke his 5000 meters personal record for the first time in 10 years in July (14:12 → 14:08). He conducted high-intensity training (e.g., VO2max interval and temp running) twice a week and did one or two easy runs on other days from April to July. In addition to these running training programs, he introduced heavy-weight strength training. The strength training session was typically held twice weekly. However, the frequency was changed to once per week if both the HRV (usually decreased) and subjective fatigue were high. The S&C coach thought that these approaches may contribute to a stable HRV (not increased HRV) and thus his superior performance.

Now let's look at the second box. He held a high-altitude training camp to train at a high intensity while avoiding the scorching heat in Japan. The HRV tended to drop during this camp (but did not deviate from the normal range), which can be an expected acute response.
  
Next up is the third box. As you can see, the HRV in September was on the rise. However, this does not appear to be a good trend for several reasons. First, the value deviated from the normal range. An increase in HRV typically indicates a positive adaptation of training. However, an increase above the normal range is an exception. Second, the increased trends in summer would be observed regardless of whether performance and conditions are good or bad. In fact, a similar case was observed in other elite Japanese endurance athletes. Finally, his training during this period did not go smoothly. Therefore, both the runner and the S&C coach did not perceive this period as "coping well".

In the final box, number 4, we can see that Asuka got sick after working as a 30-km race pacemaker. Eventually, sickness has had a big impact on his training and marathon-race plans for this season. However, because he suffered from several orthopedic problems in his lower extremities, this period offered an opportunity for physical and mental recovery. In fact, the figure shows that the HRV  went back to the normal range in this phase.
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Fortunately, he could recover from the sickness and resume training little by little. His current aim is to get a seat for the Qualifying Championship for the Paris Olympics in Japan.

For elite runners, it is difficult to judge the boundary between training loads leading to improved performance and overdoing that load to injury or overtraining.

​A runner’s condition is also affected by various factors other than training.

Regularly reviewing HRV, training status, subjective feeling, daily life events, etc. is important to optimize the condition of all runners.