New Findings on Walking and Running - Medical Frontiers

According to the World Health Organization, physical inactivity is the fourth leading risk factor for death in the world. Walking has gained attention as one of the most effective ways of combating a sedentary lifestyle. Japanese researchers have published reports suggesting that a unique walking method developed in the country improves conditions such as diabetes and hypertension. This method is revolutionizing cardiac rehabilitation. There are also new findings regarding running. Researchers have discovered that slow running may activate the brain. Today we focus on these discoveries and introduce easy exercises that you can start right away to improve your health. So let's begin. Located about three hours northwest of Tokyo by train is the city of Matsumoto. While global studies traditionally emphasize the number of steps, researchers in Matsumoto are pioneering a unique approach that goes beyond mere step count. This method, known as Interval Walking Training, or IWT, involves alternating between slow walking and fast walking. A study was conducted with middle-aged and older participants divided into three groups. One that did no walking, another that walked 10,000 steps a day, and a third that did 30 minutes of daily IWT. Five months later, the IWT group showed a decline in systolic blood pressure over four times greater than the 10,000 step group. Additionally, their diastolic blood pressure had decreased 2.5 times. If this new result can be maintained for five years, the risk of stroke is believed to drop by 40 percent. Another study found that IWT lowered the depression index by 50 percent in middle-aged and older people with depression symptoms. It also extended their sleep efficiency by 12 percent. Interval Walking Training was developed by a team at Shinshu University in Matsumoto. The university is playing a leading role in teaching IWT to middle-aged and older people. I'm 82 years old. I think I should do something for my health. I used to get sick, but now I don't get sick at all. It's a big change. Before beginning IWT, participants wear a device that can measure the amount of exercise they do. Participants begin by walking at their own pace. They walk at a relaxed speed, as if taking a stroll. Three minutes later... Following the instructions, they speed up. They take large steps, swinging their arms widely and opening their chests. They increase their pace until they're slightly out of breath. After three more minutes... The participants return to a slower walking pace. They take the opportunity to catch their breath or stretch. Three minutes of slow walking, followed by three minutes of fast walking, make up one set. Five sets are required, totaling 30 minutes. IWT was initially designed for athletes to boost their fitness by alternating between intense exercise and short breaks. It has been transformed into a walking method that anyone can do. It's refreshing, but I'm sweating a lot. It's probably lighter. I've been waiting for a week. A team led by Shinshu University professor Masuki Shizue has been studying IWT. Dr. Masuki, it's great to have you on the program. Thank you for joining us today. Thank you for having me. It's such groundbreaking and fascinating research. Masuki's team did an experiment with a group that did no walking, another that walked 10,000 steps a day, and a third that did IWT. After five months, the results showed that the hamstring muscles necessary for raising the legs were 12% stronger in the IWT group than in the 10,000-step group. Peak oxygen uptake, a measure of aerobic endurance, was also 10% higher in the IWT group. The exercise had improved their physical strength. Masuki believes that the group that walked 10,000 steps daily may not have walked with sufficient intensity and speed to improve their fitness. Michael Joyner, an expert in sports medicine, was among the first in the world to recognize the significance of IWT. So I think it's a real breakthrough. And what's great about it is you have the community involvement, you've got a lot of people involved, you've got the university involvement, and you've got principles of the same sorts of training that the elite athletes use apply to older people. So it's really just a great kind of three-fold way to send a message and do good things for older people. In 2020, the American Physiological Society featured IWT in a textbook used by physicians and researchers worldwide. These are becoming textbook studies widely cited. And again, both the specifics of their program, but also as people try to learn lessons from their success and see how those lessons can also be applied to their own programs. Interval walking training was developed by Nose Hiroshi, under whom Masuki studied. Professor Nose, it's so lovely to meet you. So how do we actually do it? Nose recommends stretching before IWT. The proper posture is crucial for walking without fatigue. Look straight ahead. Lift your hands as high as possible, then lower them. Begin with a slow walk. First is a nice slow, so we can have a conversation. Big stride or not such a big stride? I have to ask, how old are you? You look so incredibly young. Mentally young. That's the most important thing. It's so important to be mentally young. You should feel relaxed and be able to enjoy conversation during slow walking. Then at what sort of pace are we walking at for the high-intensity walking? So the key thing is, it's really a nice long stride. By bending your arms at a right angle and swinging them back and forth widely, you will be able to walk with large strides naturally and comfortably. For slow walking, go as slow as you like. For fast walking, aim for a speed that slightly tightens your calf muscles. How many minutes do we need to be aiming for? Okay, great. So 60 minutes is really the key thing a week. There's no need to do this all at once. Spreading it out into a few minutes walk several times a day will give you similar effects. The team at Shinshu University is conducting joint research with a local hospital to explore the possibility of introducing IWT into the rehabilitation of heart disease patients. Onozawa Koichi suffered a myocardial infarction in 2015. For a while, he couldn't walk properly and had difficulties standing up. There are significant challenges in the rehabilitation of heart disease patients. Before starting rehabilitation, heart disease patients are given an accurate assessment of their physical fitness and cardiovascular function. Based on the results, doctors determine a walking speed that can be comfortably managed. The patients wear a device that records heart rates and other data during IWT. Onozawa has been doing IWT for three months. Tailored to each individual's fitness level, IWT can be done comfortably and safely, even by those with heart conditions. Onozawa can now walk quickly without experiencing shortness of breath or palpitations. Initially, walking 10 minutes was a challenge, but he can now walk continuously for 40 minutes. In daily life, he can easily walk up slopes. After the session, the exercise data is shared with the hospital, allowing doctors to remotely check the patient's heart condition. In some hospitals, rehabilitation sessions are provided only once a week instead of the optimal three times due to labor shortages or patients living in distant areas. However, by introducing IWT, which can be done at home and remotely monitored, it will become possible to offer rehabilitation three times a week. Since IWT is a familiar exercise, I think it will be possible to use various times in various places of life. The increase in exercise menu options makes it easier to introduce IWT and continue. The research team conducted a study involving 10 heart disease patients divided into two groups. One exercised using machines once a week, and the other group, in addition to machine training, did IWT at least twice a week. After six months, the results showed an improvement in the pumping ability of the heart in the IWT group. The researchers also measured levels of a hormone called BNP or brain natriuretic peptide, which is secreted when the heart is under stress. The IWT group showed improvement. However, the patients who did only machine training didn't see improvement due to insufficient exercise. Onozawa's current goal is to resume running, something he used to love doing. Research on interval walking training is progressing around the world. Christian Karstoft at the University of Copenhagen is exploring its introduction into diabetes treatment. Well, we thought that the fairly low intensity was good for our population because, at least in Denmark, most of the individuals who have type 2 diabetes are not that fit. They have not been used to doing that much exercise. Karstoft conducted a study involving middle-aged and older people with diabetes. They were divided into three groups. One did no walking, one walked at a normal pace, and one did IWT. For four months, he examined fluctuations in their blood sugar levels. He found that only the IWT group showed a 10% decline in blood sugar level variability. Smaller fluctuations indicate a better control of blood sugar levels, suggesting an improvement in diabetes. We would have to look into adherence, how we can optimize long-term adherence to interval walking training. And how we can maintain the intervention in large populations. The Shinshu University team is working to create a system in which IWT can be utilized, not only in hospitals, but also in the broader community, with pharmacies playing a central role. A type 2 diabetes patient visits the pharmacy. You are working very hard. You have a round nose. I can walk now. You don't get tired easily, do you? No, I don't. I don't get tired even after walking for 20 minutes. The pharmacy provides guidance on IWT. Patients then carry out IWT at home and submit a device with their walking records to the pharmacy once a month. Pharmacists share this data with the patient's doctor. The doctor can use the data as a reference for the next examination. The university uses the accumulated data to explore even more effective instructional methods. This patient had high fasting blood sugar levels, but they declined 8% after 5 months of IWT. I was surprised. I didn't expect this to happen to someone who didn't exercise. The best thing is that you don't have to overdo it. I'm happy that the pharmacist is looking after my body. The pharmacist told me to walk. Some people ask me, what should I do? I think it would be great if I could play a role in supporting everyone's health. IWT helps patients with IWT. When the patient's physical strength improves, he will be able to walk more easily. This will help reduce medical expenses. If you do IWT for 5 months, you can reduce medical expenses by 20%. There is some research which is now going on. Based on your incredible research on interval walking training, how does it make you feel? If we can compare ethnic backgrounds, not just in Japan, I think we will be able to see results from a larger perspective. Just like drinking water or eating rice, I hope we can do interval walking every day. I would be happy if it spread to Japan and the world. Thank you so much. A Japanese research team has discovered that a simple exercise could improve brain function. It involves slow running at a pace similar to fast walking. In running, there are moments when both feet are off the ground, while in walking, one foot is always on the ground. Slow running is a bit more demanding than walking, but the key is to run at a pace slow enough to keep a smile on your face. Soya Hideaki has been studying the impact of exercise on the brain for many years. If you have a high level of exercise every day, you won't be able to continue exercising unless you are highly motivated. If you don't continue exercising, you won't be able to accumulate health benefits. Soya's team examined how slow running affects the hippocampus in the brain using rats. The hippocampus is responsible for memory. A dysfunction of neurons in the hippocampus is thought to result in memory decline and may trigger depression and dementia. In the experiment, the rats underwent a series of experiments. While many reports suggest that running boosts memory, it was unclear whether slow running has the same effect. Soya's team investigated the quantity of genes that improve the function of hippocampal neurons. The finding reveals that the results of slow running are similar to those in normal running. In another experiment, the team had the rats run for six weeks, and examined changes in the hippocampus. These images show neurons in the hippocampus of the rats. One group did no exercise, another did light intensity running, and a third did vigorous intensity running. Showing in red are the newly born neurons. The number of new neurons increased 1.3-fold in the rats that did vigorous intensity running, compared with those without exercise. But the increase in rats that ran at light intensity running was about 1.7 times that of the no exercise group. Soya also conducted an experiment to determine whether light intensity exercise affects the human hippocampus. Healthy young participants underwent a pedaling exercise, followed by a memory test. Neural activity in the hippocampus during this test was observed using a high-resolution functional MRI. Light intensity exercise improved their test accuracy, compared with when they did no exercise. Soya also used functional MRI to examine how neural activity in the hippocampal subregions related to memory changed during the test. Neural activity significantly improved compared with when the participants did no exercise, showing that even brief, light exercise can activate the memory system. Soya also investigated how exercise affects the prefrontal cortex. Often dubbed the brain's command center, the prefrontal cortex governs attention and decision-making. He did a study comparing the decision-making speed of participants when they did no exercise with when they did light intensity exercise. First, the participants took a cognitive test. Then, for the next 10 minutes, they either did slow running or no exercise. After that, they took another test. The results showed that after slow running, the participants were faster at answering questions than when they did no exercise. What's more, when examining the changes in neural activity in the left prefrontal cortex, it was clear that the lateral part had become activated. Neural activity improved when they ran compared with when they did no exercise. Soya's team is studying whether listening to a groovy rhythm while doing exercise can activate the brain further. The essence of exercise is that exercise is a form of play. The more we expand this aspect, the stronger the effect of exercise will be on the human body. It will return to the human body. And I really hope you'll join in making it a regular habit.