"Know yourself through blood tests" - Causes of performance decline, onset of depression, and recovery -

Text: Shun Sato

RUNNERS MEDICAL REPORT

In endurance events such as marathons and long-distance running, there is a high risk not only of injury but also of internal diseases such as anemia, so elite athletes belonging to corporate teams and athletes who are seriously competing in high school and university often undergo regular blood tests.
If you experience symptoms such as fatigue, shortness of breath, or a lack of improvement in your records, and abnormalities are found in blood tests such as hemoglobin levels, improving these can lead to a recovery in your physical condition and sports performance.

Many amateur runners actually take blood tests when they feel unwell or are worried that they cannot run as well as they would like, as this can help clarify something that is not visible.

A blood test for Mr. A of RETO RUNNING CLUB also revealed the cause of his declining performance.

Perceived performance degradation

Mr. A first noticed something strange happening to his body in June 2023.

During training, I suddenly got a cramp in my leg, and my body couldn't keep up with the training that I had been able to do up until then.After that, I participated in a half marathon race, but my body stopped moving and I dropped out after 14 kilometers.

"When I DNF'd, I thought maybe my body wasn't used to the heat and I couldn't move. But when the heat arrived in July, my body felt even heavier and I couldn't increase my pace at all. I had to work really hard to run long or fast. A 4 minute 10 second pace hadn't been difficult up until then, but now it was so hard my performance didn't improve. My teammates suggested I might be anemic, so I went for a blood test for the first time in August."

A blood test at Dr. Shogo Tabata's Tabata Clinic revealed that his hemoglobin levels were normal and he was not anemic. His ferritin and serum iron levels were also within normal limits, so there were no problems. Dr. Tabata pointed out a certain item that is often found to be relatively low in male amateur runners.

"The reason why Mr. A's blood test showed a lower value than the standard value was testosterone." (Dr. Tabata)

Testosterone may be an unfamiliar term, but it is a male hormone that plays an important role in the development of male reproductive tissue and promotes secondary sexual characteristics such as increased muscle and bone mass and hair growth.It is also a blood-forming hormone, so a decrease in testosterone can cause anemia.

Symptoms of low testosterone

What causes testosterone to decline and what symptoms does it cause?

"Adult men don't experience the same rapid changes in sex hormones that women experience during pregnancy and childbirth, or around menopause. However, testosterone levels begin to decline gradually from their 20s onward. The timing and speed of this decline vary from person to person, and some men in their 30s can experience menopausal symptoms (such as decreased sexual function, depression, sleep disorders, and fatigue) due to declining testosterone levels. In recent years, it has become clear that excessive endurance sports can also cause a decline in athletic testosterone levels, in addition to aging. Mr. A was in his 30s and relatively young, but he had run marathons, so exercise stress due to overwork was the first suspected cause. Furthermore, mental stress from work may have contributed to the drop in his testosterone levels. This can result in hypotestosterone syndrome and impaired athletic performance. Furthermore, if testosterone levels remain low for a long time, there is a risk of impaired hematopoiesis, which increases the risk of anemia. Similar to male menopause, this can also lead to fatigue, sleep disorders, and metabolic syndrome." (Dr. Tabata)

Restrictions on running and daily life

It is recommended that Japanese men have their free testosterone levels measured, with the normal free testosterone level being 11.8 pg/ml or higher. A free testosterone level below 8.5 pg/ml is considered a level that suggests male menopause, but Mr. A's level during his test was 8.4 pg/ml. The mechanism by which exercise reduces testosterone levels is not yet fully understood, but factors such as stress, disruption of hormones such as cortisol, mechanical stress on the testicles due to exercise, and lack of energy are thought to be involved. Dr. Tabata advised him to limit some aspects of running and daily life in order to improve his levels.

"The doctor advised me to avoid high-intensity training such as pushing myself to the limit or key training sessions in order to reduce exercise stress. Normally, moderate sports activity increases testosterone levels, so rather than stopping running, he advised me to reduce the load and continue jogging. He then advised me to keep an eye on my condition, and if there is no improvement, it is likely that mental stress is affecting me, so we will consider starting hormone replacement therapy while also providing mental care."

Worsening symptoms

After that, Mr. A stopped doing point training and switched to mainly jogging. As he watched his teammates doing high-intensity training to improve their condition and prepare for races, he began to feel frustrated that he couldn't run. Perhaps his sense of impatience was causing him more stress. He began to feel dizzy, break out in a cold sweat, and feel fatigued, not just when exercising, but even at home.

"It felt like things were slowly getting worse."

When I participated in a training session in September, I couldn't even jog and my body became immobile. I felt that it wasn't physical exercise but mental stress that was having a major impact, so I went to a psychiatrist. When I showed him the results of my previous blood test, he told me that my testosterone levels were low and that I should start treatment for that. He also told me that I should take time off work, so I got a medical certificate and submitted it to my company.

To check the situation again, I had a blood test one month after the first test. My free testosterone level had dropped from 8.4pg/ml to 7.8pg/ml.

"Your numbers are dropping, so let's start hormone replacement therapy."

That's what Professor Tabata told me.

What exactly is testosterone replacement therapy?

"Testosterone is a banned substance in doping, so professional and corporate athletes who may be subject to doping tests cannot receive testosterone replacement injections. Treatment is administered approximately once every two weeks. If the treatment is effective, subjective symptoms will improve within two to three days. Some male menopause causes anemia, but testosterone replacement increases hemoglobin levels, improving anemia. However, the effectiveness varies from person to person, so replacement therapy may not work for some people. In particular, in cases where mental symptoms such as depression are severe, it is not uncommon for male menopause and depression to overlap. If symptoms do not improve with replacement therapy, psychosomatic or psychiatric approaches should be considered. This requires careful consideration, not only of blood data but also of the progression of subjective symptoms." (Dr. Tabata)

Onset of depression

Mr. A started testosterone replacement therapy.

It was effective, and I was able to move my body a little more. However, after a week, my condition returned to normal. I returned to work after a month's leave of absence, and although I was fine for the week after the injection, the next week I was at my physical and mental limits. The difference in symptoms was so great that I consulted the doctor at the urology hospital where I receive hormone replacement injections.

"In September, my male hormone levels were low and I was diagnosed with male menopause. In October, I started receiving injections, but my condition worsened to the point where I could no longer get out of bed and was unable to move at work. Menopausal symptoms don't usually get that bad, so it's very likely a mental health issue. I was told I should get checked out by a psychosomatic medicine specialist."

I was diagnosed with depression at a psychiatric clinic and started taking one antidepressant tablet per day. My testosterone levels continued to drop, dropping to 6.5 pg/m in November and 6.1 pg/m in December, but my urologist told me, "As long as you don't experience dizziness or other symptoms, there's no need to worry about the levels." Since I was experiencing severe symptoms of depression, such as fatigue and mood swings, I stopped taking hormone injections and just took the antidepressant.

"It was very effective. A stress-free environment is important to improve symptoms, and jogging was the best thing for me. Running felt good, and it helped me release stress. By moving my body, I gradually became more positive."

Gradually regaining myself

I'm still taking medication this year, and my running is just an extension of jogging, but I'm increasing the intensity a little. I've scheduled the Itabashi City Marathon for March, but if the symptoms return and it affects my return to work, I don't think there's any need to push myself.

"Looking back now, when the blood test results showed low testosterone levels, I wondered if I was sick, and it affected my mental health. I was unable to run in the Niigata Marathon (October 8th), which I had been betting on, and I lost my goal, which made me feel even more depressed. My doctor told me that it's not the fact that the numbers are low that's the problem, but the fact that they cause symptoms. If I didn't have symptoms, I could live a normal life, but if I judged based on the numbers alone, my anxiety would increase and I would fall into a quagmire of negativity. Blood tests can clarify things that are unknown, but hormone-related numbers in particular are indicators that vary greatly from person to person and fluctuate, so it's important not to get too nervous about it."

Over time, Mr. A is slowly regaining his sense of self.

The importance of undergoing a blood test

Dr. Tabata had this to say about amateur runners taking blood tests:

"When amateur runners get blood tests, they don't need to get them as frequently as corporate athletes, and usually about once a year is enough. However, as with anemia, there are cases where a diagnosis cannot be made without testing, so if you experience symptoms such as not feeling well, feeling tired, or not being able to perform well in practice or races, it's a good idea to get a blood test. Knowing the state of your body from an internal medicine perspective is important for living a healthy daily life."

Of course, there are some diseases, such as mental illnesses, that cannot be diagnosed through blood tests, but blood tests are still valuable from the perspective of exclusion diagnosis. Even if you have no subjective symptoms, it may be worthwhile to get a blood test as a way of self-management, such as knowing your physical condition.