(Kojima) For example, let's say a person runs a lap around Ohori Park (a 2 km park in Fukuoka City). If you haven't run in a while, your breathing will become labored and your legs will start to feel heavy in the middle of the run, right?


(RP) Yes. We become short of breath, our legs don't go up, and after we finish running, the lower half of our body starts to feel wobbly.


(Kojima) The point at which "breathing becomes difficult and muscles stop moving" is the "Threshold" for that person. In other words, it is the limit of cardiopulmonary function and muscular strength at which "if the pace goes any faster, the body will not be able to handle the lactate acid.


(RP) As the workout load increases, lactate acid, a metabolic product of glycogen, accumulates in the blood. So you are saying that the "hardness" of running is proportional to the ability to process lactate acid concentration in the blood, right?


(Kojima) That's right. Therefore, in the world of running, the "LT value (Lactate Threshold)" is used to determine "the limit at which a person can run the fastest and the longest." And raising the upper limit of this LT value is an important condition for improving running ability.


(RP) I see. So it is important to train cardiopulmonary function through interval running, which primarily focuses on I pace, which is faster than T pace, out of the five stages of E, M, T, I, and R. I understand that when we put a high load on the heart for a certain period of time at a speed close to the limit, the body gradually adapts and its lactate acid processing capacity also increases.


(Kojima) Yes, LT values do not improve in a short period of time, but if you activate the capillaries through steady practice and increase the capacity and volume of oxygen transport, the blood will do a "good job" of it, enhancing the body's overall performance and changing the point at which fatigue occurs.


(RP) If the amount and speed at which the blood can transport oxygen throughout the body is increased, then we can run longer distances, for longer periods of time, and at a faster pace without getting tired, and our times will improve as a result. So "sub-4" (sub-4 hours in a full marathon) or "sub-3" in a marathon is one of the results of this process?


(Kojima) Yes. The history of marathon has gone through the steps of "running with legs," "running with heart," and "running with guts," and has entered the era of "running with blood." Today, various factors such as form, shoes, and cells are taken into consideration, but the importance of cardiopulmonary function, which has been essential for a long time, is also being reviewed from a new perspective every year with the development of sports science, IT technology, and life science. However, the importance of cardiopulmonary function, which has been essential since ancient times, is being reevaluated from a new perspective every year due to advances in sports science, information technology, and life science. Since running is a whole-body exercise, the way blood works remains as important as ever, and while there are numerous conditions for getting faster, improving VO2Max remains one of the most important conditions.


(RP) "Working blood" is a unique concept. When we realize that runners are thinking about that, it changes the way we look at it.


(Kojima) We are not professional athletes, and not everyone is running to improve their marathon record. Many runners do jogging or running as a friendly way to improve their health in life, and to improve their performance in work, study, and daily life. Therefore, it is a great gain for all runners if they can obtain "working blood," an asset gained through aerobic exercise.


(RP) For everyone, "healthy, hardworking blood" is an important treasure. Improved blood circulation also raises basal body temperature, improves coldness and swelling, and leads to weight loss. But I also worry that running might make my legs fat.


(Kojima) Running is a sport that uses "slow muscles" (thin, red muscles that exert endurance) rather than "fast muscles" (thick, white muscles that exert instantaneous force), so it actually makes your legs thinner. Moreover, the "forefoot running" method, which has become mainstream in recent years, lands on the forefoot and uses the hip joint, so many runners these days have thin thighs and calves. My problem is that it is difficult to find men's jeans in slim sizes that fit my waist and legs.


(RP) That is great news, especially for women. Losing weight, getting in shape, and also having a healthier heart, lungs, muscles, and blood flow are all good things.


(Kojima) The performance of the human body is proportional to the quality of blood vessels and blood, and many health problems occur in response to problems with blood vessels, blood flow, and blood. I have always believed that the greatest gift you can get from running is "working blood," even if I would not go so far as to assert that "blood is the greatest determinant of running ability."


(RP) Lifestyle-related diseases, which are serious problems in modern world, also worsen into diabetes, hypertension, gout, arteriosclerosis, aneurysm, cerebral infarction, stroke, cerebral apoplexy, fatty liver, lipid disorders, heart failure, myocardial infarction, angina pectoris...and most of them are caused by vascular problems if left untreated. Although the names of the diseases change when they occur in different places, the origin is the deterioration of vascular health, and the reason for the deterioration is that cholesterol and other factors cause blood to stagnate and blood flow to deteriorate, resulting in obstruction of blood circulation, which in turn causes abnormalities in the blood vessels.


(Kojima) It could be said that jogging and running are the best free hospitals for everyone. I have close friends who are pharmacists and dietitians, and I am happy to hear more and more people say, "Kojima-san is healthier than I am," these days.


(RP) I now understand how you get involved in running on a daily basis and how runners think about cardiopulmonary function and physical fitness through improving their VO2Max. Now, could you tell us how you would like to maintain your blood vessels in the future?


(Kojima) For the time being, I would like to gradually activate inactive capillaries, the so-called "ghost blood vessels. " Expanding the area where blood can work itself is one of the important goals of running.


(RP) First, you mean to increase the "workload of the blood" itself.


(Kojima) After that, I want to put a balanced load on the blood vessels that are not in good operating condition and the "old/ghost blood vessels" that have started to move after a long time, and to make the blood vessels more flexible as a whole. I would like to do this through long, slow jogging or "LSD running (Long, Slow, Distance: a running method that leisurely enhances cardiopulmonary functions by running for long periods of time, at low speed, and over long distances as a standard)" and in parallel with short, fast-paced interval running, repetition running, and build-up running. Considering the latter half of my life, I believe this will help prevent arteriosclerosis and other vascular diseases in the future. I don't want to live a life that leaves me worried about my body in my old age.


(RP) Next to quantity, you train blood vessels through improving your "quality" to increase your running ability, and at the same time eliminate health concerns.


(Kojima) If we can expand the area where blood can do its job, improve the performance of blood, and train strong and supple blood vessels that can withstand various types of strong and weak blood flow, and then make the blood itself healthy through healthy eating, VO2Max will also improve comprehensively, which will be reflected in performance in running, work, and study.


(RP) Finally, do you have a message for runners and working people?


(Kojima) Since I am not a professional athlete, I would like to generously share any information that I find useful for enjoying running and improving my record. I have run with many people who have given me tips on how to run faster, longer, and more enjoyably. I believe that if we, the middle-aged and elderly, are healthy and energetic, the foundation of society will be stable and good for the future of Japan. In order to continue to be good members of society, enjoying not only work but also daily life, study, and hobbies, we should know and train our bodies, which are our fundamental asset, get healthy blood vessels, and take good care of them. In this way, I will be happy if I can enjoy running for as long as possible.


(RP) Thank you very much for your time today.


Official ambassador and exclusive contract runner of Blut Runners Q

Mr. Naotaka Kojima(Instagram @naotaka_kojima



Born in Fukuoka Prefecture in 1975, Mr. Naotaka Kojima passed the overseas work exam while a student at Seinan Gakuin University in 1995 and joined a trading company in Malaysia. After returning to Japan, he worked as a business writer and sales planner in a business magazine publishing company in Fukuoka City.

In 2001, he started his own business as an editor and translator, and after working in the business education field, he started his trading business in 2009.

After serving as a director at a medium-sized general contractor in Malaysia, a food trading company in Serbia, and a resource development investment fund in Hong Kong, he has been the managing director of J-Tech Transfer and Trading (export and international technology transfer business) since 2014. He is currently working hard to develop overseas sales channels for small companies in Kyushu and western Japan.



■Running Record

March 2021 "Hitoyoshi Marathon" (half marathon category) 7th/402 runners (1:27:52)

1987 Fukuoka Prefecture Elementary School Athletic Game (Heiwadai Athletic Field), 800m, 8th place/prefecture

1988 Chikushi District Marathon (5km), champion (18:10)

1990 "Tobiume National Athletic Game" torch runner (16:34/5km) *selected from junior high school track and field clubs in the prefecture