Alternately walking fast and then more slowly is a good way to beat the summer heat, according to a university professor.
Prof. Hiroshi Nose of Graduate School of Medicine, Shinshu University, who devised this method of coping with the grueling summer, said that overall health should improve one week after starting the exercise and a loss of weight may be noticeable after two weeks.
However, before the summer heat wave rolls into town, it would be a good idea to build up a strong body to endure temperature changes before heading out into the street. Nose's method has been well-received as it can be quickly and easily adopted.
He recommends five sets of three-minute walks, first fast and then more slowly, for a 30-minute total, at least four times a week. This should improve a person's physical strength, he said.
Heatstroke occurs when body fails to properly release heat through such means as sweating and widening of blood vessels in the skin.
Nose said milk should be drunk right after the exercise as it improves liver function, which increases the volume of blood. In the case of a person older than 60, the effect can be seen in about eight weeks, he said.
"If a liver is compared to a car engine, blood is the radiator. With more blood, vessels in the skin widen more easily, enhancing functions that control body temperature," the professor said.
About 900 elderly people practiced the walking method at the request of Jukunen Taiikudaigaku Research Center (Sport science university research centre for senior citizens), a nonprofit organisation in Matsumoto, Nagano Prefecture. Nose serves as vice president.
Participants visit local facilities once a month and receive guidance from instructors based on the data of pedometers that also calculate how many calories have been expended.
Ai Hashiba, 72, who has used this exercise method for nine years, makes a habit of drinking milk afterward. She said she did not suffer much from the summer heat. "I exercise by walking for 30 minutes every other day," Hashiba said.
It is important not to overdo things, to stop exercising if you feel unwell and do not walk during the hottest times of the day.
One way to avoid heatstroke is to drink plenty of fluids to replace those lost through sweating. Tsutako Hidaka, an official at a public health centre in Tachikawa, western Tokyo, recommends sipping water rather than gulping it down.
The daily requirement of water for an adult man is about 2.5 liters, and about 1.2 liters should be taken in through drinking water.
This amount of water is difficult to drink at one time, but 150 milliliters of water can be drunk eight times a day.
According to the Tokyo Fire Department, the number of emergency calls in summer tends to sharply increase after 10 a.m., when temperatures rise.
"By the time you feel extremely hot or thirsty, it's already too late to drink water," Hidaka said. "It's important to drink fluids beforehand."