Meanwhile, in Japan

Felt like writing something about exercise. After all, my education is in exercise science and not nutrition. This is about an exercise trend from Japan. It might be the next big thing in both muscle building and physical therapy and it may hurt like hell.

This is Kaatsu training!

Simply speaking Kaatsu training is occlusion training or training where a large part of the blood flow to and from the exercising muscles are restricted by a cuff. Its purpose is to increase muscle size without having to use high resistance and heavy loads.

Increasing muscle size is dependent on a variety of factors, but the important point is that muscles grow due to adaptation to stress. The larger the stress the stronger the effect (to a certain point) and it is the total amount of physiological stress that stimulates muscle hypertrophyIncreasing total stress can be achieved by for example increasing resistance, reducing break time, increasing number of sets and also as it appears, restricting blood flow.

Kaatsu training consists of performing low-intensity training while a relatively light and flexible cuff much like the ones used to measure blood pressure, is placed on the arms or legs usually close to the trunk. Inventor of Kaatsu training, Yoshiaki Sato, has worked with Kaatsu for more than 40 years and is still going strong.

Kaatsu may be an important tool in rehabilitation. Yoshiaki Sato, then at the Department of Ischemic Circulatory Physiology at The University of Tokyo describes his own experience with Kaatsu training: “…witnessing an older wheelchair-bound individual regain the use of his legs as well as another individual regaining sensation…”

Yoshiaki Sato in the 60’s while experimenting with Kaatsu




Kaatsu training does require some caution because blocking blood flow too much may be deleterious and cause thrombosis. Mr. Sato was himself hospitalized in the 1960’s after exercising with constricted blood flow and disregarding an increasing numbness in his legs. He experienced an episode of acute shortness of breath and was hospitalized with a pulmonary embolism. Sato later patented Kaatsu and made guidelines to reduce the risk of overdoing it like he himself did.


From Abe et al 2005
From the beginning it was clear that blood flow constriction combined with resistance exercise gave some exercise advantage even at levels as low as 20% of 1 repetition maximum (RM). Several studies have found increased muscle size at exercise intensities far lower than what may cause muscle growth under normal conditions.

In 2005 Sato with Takashi Abe and Charles F. Kearns demonstrated effects at even lower intensities. They made 18 young men walk on a treadmill 2 times a day, 6 days a week for 3 weeks. They did 5 sets of 2-minute bouts with treadmill speed at 50 m/min, with a 1-min rest between bouts. 9 of these men walked with a cuff round their thighs restricting blood flow.

The Kaatsu group experienced higher growth hormone levels during exercise and by day 4 their muscle-bone cross sectional area was significantly larger than that of the control group. By week 6 it had increased 6% in the Kaatsu group and nothing in the control group. In the Kaatsu group mid thigh quadriceps cross sectional area increased by 5.7% while hamstrings increased 7.6%. Leg press and leg curl 1RM strength increased by 7.4% and 8.3% respectively in the Kaatsu walk group, but not in the control-walk group. 

These results may be of great significance for elderly and frail people. Normally, if you want to achieve significant muscle size increases you must exercise at high intensities and often with large external loads (>65% of 1 repetition maximum). These training intensities however may not always be possible in the elderly. Here the scientists showed that walking in a relatively slow tempo can build muscles. This is great news, because muscle wasting is a serious problem especially in the older part of the population and may cause great disabilities and need for care.


Yoshiaki Sato in his 60s still experimenting with Kaatsu
When exercising limbs have a restricted blood flow the physiologic stress increases and muscles grow more than non restricted muscles. But recent data also suggest that non restricted muscles in multi joint exercises may benefit from Kaatsu. A recent pilot study examined the effects of low intensity bench press with restricted blood flow on chest muscle and triceps hypertrophy.

10 men were divided into low intensity bench press with or without occlusion. The exercise consisted of bench press at 30% of 1RM, four sets of a total 75 reps, twice daily, 6 days a week for 2 weeks. By the end of two weeks triceps and pectoralis muscle thickness increased 8% and 16% respectively in the Kaatsu group while the number were -1% and 2% in the control group. 1RM bench press also increased significantly in the Kaatsu group only.

I won’t go into the mechanisms here, but they are still poorly understood. I was once a part of an occlusion exercise experiment where I had 7 biopsies taken from my vastus lateralis muscles. I think one of the things the researchers were looking at was heat shock proteins. Growth hormone secretion has been shown to be increased with occlusion, some have suggested (mostly on the basis of animal studies) that myostatin and cortisol may be involved. Other hormones and growth factors have been measured, but no single mechanism has stood out yet.

Several studies on occlusion training have, in addition to hypertrophy and increased strength found increased oxygen uptake. A recent Korean study found that 2 weeks of occlusion walking increased maximal oxygen uptake in trained athletes. 

Although I am uncertain of the importance of Kaatsu in sports and regular recreational exercise (it is rather uncomfortable when you feel your legs pumping, turning red, and going numb) it is definitely an interesting method that might prove an important tool in physical therapy both for older people and athletes recovering from injuries.

So if you want to do it like they do it in Japan, just strap yourself in!

The frustrations of a low carber

Science moves in mysteries ways. Despite its goal to be an objective tool describing the world as it is, science, when used by us humans, is not objective. Once a result, mathematical formula or any data acquired is interpreted the objectivity seizes to exist. And this is exactly how it should be. Data are worthless if not interpreted by someone.

So the trouble with science, when there is trouble that is, is not in science per se, but in the interpretation. Unfortunately, peoples interpretations of science can make you pull your hair out in frustration. This is what I imagine Dr. B.G. is doing here

An article on low carb dieting appeared yesterday in one of the biggest Norwegian newspapers. A doctor using the diet explained how it worked and the reporter had asked the opinion of two people with relations to the national dietary committee. They of course were very skeptic towards low carb. Their main arguments were that low carb increased the risk of heart disease due to larger saturated fat intake and that the diets did not provide sufficient micronutrients. Frustrated as always, when reading crap like this, I thought to myself that there can only be two reasons these so called experts can argument like this. 1, they are ignorant. That is, they don’t actually know what they’re talking about, but won’t admit it or aren’t aware of their own ignorance (this is what I think is most common) or 2, that they are in fact lying. The two options are easy to deduce, because science (the wonderful objective tool we use to explore the truth) has shown the arguments mentioned to be wrong. Not completely, never to be anything other than wrong wrong, but wrong with a very very high probability, so much that we can safely say that they are wrong.

The trouble with saying saturated fat intake has been found to correlate with heart disease as one of the Norwegian “experts” claimed, is that the statement doesn’t even resemble the truth. What is more frustrating is that the people reading the article are given only this seemingly authoritative statement. The truth, on the other hand is given no attention. The truth is that, yes saturated fat has been found to correlate with heart disease, but such a correlation is less frequently found than no correlation at all and if all data are seen as one no correlation exists. So the truth is that there is no correlation. But even if a correlation was frequently found it would still be a horrible argument. We need more than correlations. We need likely physiological explanations for how saturated fat may cause heart disease. These either do not exist, or I have done a horrible job trying to find them.

The trouble with correlation
One of the largest misuses or misinterpretations in health science lies in the interpretations of correlations. A correlation is when to events or factors occur in relation to one another. Shoe size for example, might be found to correlate with intelligence. That is, if we do a study of a large number of people of different ages measuring their intelligence with a standard test and measuring their shoe size, we are likely to find that those with larger feet generally score higher on an intelligence test. The reason is not that brainpower is increased by larger foot size, but that younger people with smaller feet get lower scores on a standardized test than those more adult with larger feet. Thus, shoe size and intelligence correlate. They are related somehow. The important part to remember from this story is to not surgically enhance your foot size in order to increase your intelligence.

Some studies have found that overweightness and obesity correlates with reduced physical activity. There are again, at first glance, two likely explanations for this. 1, that physical inactivity causes overweight or 2, that overweight cause physical inactivity. There is also a third option depending on our definitions – it is that both overweight and physical inactivity may be causes of a common underlying factor. Such a factor could be a hormonal pattern that causes a great fat storage at the same time making energy reserves needed for physical activity unavailable. Thus overweight and physical inactivity may be brought on by the same underlying cause. Still, the correlation does not tell us that increasing physical activity will make us lose weight.

Now why cant I find this at the gym?
Lately overweight and obesity is blamed on lack of physical activity. Claiming lack of physical activity directly causes overweight makes just as much sense as saying dieting causes overweight (although if people diet using low fat low calorie diets the latter part actually is quite probable). Strange as it may seem dieting also correlate with overweight. Luckily for us when we encounter correlations like these we (most of us anyway) have the wonderful gift of common sense. Although science as a tool strives to be as objective as possible all data must be interpreted by humans, thus making it subjective. Common sense however can reduce the risk of making grave errors in this interpretation process.

Quite recently a group of scientist found a correlation between meat intake and overweight. They quickly concluded that reducing meat intake might be an important step in fighting overweight. In this finding as in all other correlations there are many options for causality. One possibility of course is that meat actually does have a powerful effect on triglyceride storage in fat cells – a mechanism the scientists should have elaborated on. Another possibility is that meat is often consumed with other foods that are in fact causing overweight whether consumed with meat or not. This might make overweight and meat intake correlate without meat playing a causal role at all.

The trouble with us
The sum of our knowledge is far greater than any single human can have. A person can, no matter how supersmart he or she is, only know a small fraction of all existing knowledge. I don’t have time to learn why, according to string theory, the world must have 9 dimensions or 10 if we include time, and I definitely don’t have time to learn how to build a house. I have to take the professors, carpenters or text books word for it. What other choice do I have?

The national nutritional guidelines are faulty. In fact, all official nutritional guidelines I have seen are very poor and hardly ever qualify as strictly scientific. But the regular Joe out there has no other choice than to trust the guidelines and the purveyors of it. There are many people who share my view on nutritional guidelines, and many of us experience the disbelief regular Joe show when we tell him that the guidelines are wrong, and that “you should do as I say instead”. Of course there’s disbelief. If someone told me that smoking was super healthy, that the government was wrong and that I should smoke 20 a day, disbelief would be the primary emotion occupying my mind as well.    

It’s all very, very frustrating and I find myself spending more and more time trying to think of ways to make all this go away. To make people see the errors of nutritional guidelines or any other pseudoscience for that matter. I also wish people in general would know that homeopathy is bollocks.

I sometimes think that if skepticism and argumentation theory was a larger part of what was being taught at schools, things might be better. But fantasizing of ancient Greek idealism, I find myself thinking that the Greeks were probably just as frustrated as I am. It seems an inborn human trait to not change views easily whether faced with better arguments or not. How else can we explain the current situation in nutritional science? Although good arguments aren’t enough, I still think all the scientists, bloggers, twitterers and other information spreaders out there fighting for the cause of proper use of science are doing a very important job. Perhaps the most important thing we can do at this time. Ah, well. As for me, I have found that nothing cures my frustrations like a cold beer, carb-filled or not.