We performed a physio-psychological research on the mental, physical relaxation and health-keeping effect of Shinrin-yoku (forest walking) in Kawaba village. Eleven male and 8 female healthy elderly residents in Kawaba village, whose average age was 74.0±3.5 years old for male and 74.9±2.9 years old for females volunteered for this experiment. All members walked for one hour in the Kawaba Forest on August 17 under cloudy skies, 30-32°C temperature, 58-60% humidity, and, 0-2m/sec wind condition and walked again for another one hour in a non-forest rural agricultural area on August 21 under almost the same weather conditions. Phytoncides in the air, Profile of Mood State (POMS) test, blood pressure (BP), heart rate (HR), fasting levels of serum natural killer cell activity (NK), plasma catecholamine (adrenaline, noradrenalin and dopamine), plasma cortisol, and serum adiponectin were measured before and after walking. Phytoncides were detected in the forest and non-forest, all members showed a decrease of POMS total scale, BP, adrenalin and serum cortisol. Six (3 male and 3 female subjects) of them expressed an increase of serum NK cell activity after the forest-walking. One female showed a high serum NK cell activity after both forest and non-forest rural walking.
Our experiment on the forest-walking in Kawaba village indicated that its relaxation and health-keeping effects, probably due to walking in the fresh forest air.

  Strength training performed while restricting blood flow is believed to cause the secretion of growth hormones under low load intensities and allow for muscle hypertrophy and increased muscle strength. This has potential clinical applications for elderly individuals and people with existing conditions. However, previous research has been performed on land, with hemodynamics and growth hormone secretion trends for training performed underwater unclear. Against this background, we investigated the effects of blood flow restriction training underwater on hemodynamics and plasma growth hormone (GH) levels. Twelve healthy university students were divided into two groups: a localized immersion group where only the upper limb of the dominant hand was submerged, and a whole-body immersion group where participants were submerged to the xiphoid process. Immersed according to respective group protocols, both groups performed flexion and extension of the shoulder joint for 10 minutes with a pressurized cuff at the base of the upper arm under both 0 mmHg and 50 mmHg cuff pressures. Measured hemodynamics were heart rate, systolic blood pressure, and diastolic blood pressure. Plasma GH levels were measured from blood samples. This study revealed that underwater blood flow restriction strength training induced plasma GH level secretion under 50 mmHg conditions. In addition, high levels of GH secretion were shown in the localized immersion group for strength training even when the cuff was not pressurized. Conversely, no significant differences were evident in any measured hemodynamic categories. Results suggest that, in addition to cuff pressure, blood flow restriction training is affected by the body part immersed in water.

  Aquatic walking, which is influenced by the physical characteristics of water such as buoyancy, resistance, water pressure, and water temperature, is known to be effective for reducing stress on joints and increasing muscular strength. However, there is no consensus on its influence on blood pressure changes in elderly people. To address this uncertainty, we researched the effects of aquatic walking on the blood pressure of elderly people. Study participants were 48 females enrolled in a class to prevent the need for nursing care. In accordance with the diagnostic criteria for hypertension, participants were divided into two groups based on initial blood pressure measurements: a “high blood pressure group” with 27 people and a control group with 21 people. Both groups did the following program once a week for five weeks: 10 minute warmup, 15 minutes of aquatic walking (forward, backward, and sideways walking), 10 minute break, and additional 10 minutes of aquatic walking. Systolic blood pressure, diastolic blood pressure, heart rate, and average blood pressure of the participants were recorded. Results showed that the high blood pressure group showed significant decreases in systolic blood pressure after one week, and significant decreases in both diastolic blood pressure and average blood pressure from three weeks onward. No significant change was evident in the control group. However, comparing values measured immediately before and after aquatic walking showed that the control group had a significant post-aquatic walking increase in both systolic and diastolic blood pressures as well as a significant decrease in heart rate. Similar significant post-aquatic walking increases in systolic and diastolic blood pressures as well as a significant decrease in heart rate was also evident in the high blood pressure group from five weeks onward, once their measured values had improved. These results suggest that continuing an aquatic walking program will lower the blood pressure of elderly individuals meeting the diagnostic criteria for hypertension, but it is necessary to be attentive to physical condition because blood pressure increases immediately after aquatic walking in non-hypertensive individuals.

  The positive healthy physiological effects of shinrin-yoku in elderly persons were studied. Shinrin-yoku or forest bathing is considered to promote physical relaxation and to have physical and mental health benefits. In this experiment the subjects were elderly 24 male (65.5±2.5years) and 24female (65.0±3.0years) persons who participated in three measurements of shinrin-yoku effects from 2008 to 2010. All the subjects were healthy and volunteered for the experiment. The subjects participated in the shinrin-yoku measurements three times of two hours each on Wednesday in the third week of August in each year. The weather at the time of the three measurements was clear, with temperature of 30°C-32°C, humidity of 58%-60% and wind velocities of 0m/sec-2m/sec. Non-shinrin-yoku measurements were also performed on a different day in an indoor resting environment with the same subjects under the same conditions. For both the shinrin-yoku and non-shinrin-yoku measurements, the subjects were divided into three groups of 8 male and 8 female subjects equally. One was for the visual isolation group in which subjects wore eye masks, another was for the smell isolation group in which subjects wore masks, and the other was the control group in which subjects wore non-isolation material. The concentration of phytoncides in the air was measured using gas chromatography mass spectroscopy. Heart rate (HRs), blood pressure (BP), fasting levels of plasma catecholamine (adrenaline, noradrenalin and dopamine), plasma cortisol and circulating natural killer (NK) cell activity were measured before and after shinrin-yoku. Three kinds of phytoncides derived from trees were detected at the forest-bathing measurement spot in this study. The mean HRs for male subjects under shinrin-yoku and non-shinrin-yoku were 89bpm and 85bpm respectively. The mean HRs for female subjects under shinrin-yoku and non-shinrin-yoku were 86bpm and 85bpm respectively. In the smell isolation group and the control group, systric blood pressure for male and female subjects decreased significantly after shinrin-yoku. In the smell isolation group and the control group, diastolic blood pressure for male subjects decreased significantly after shinrin-yoku. In the smell isolation group and the control group, adrenaline levels for male and female subjects decreased significantly after shinrin-yoku. Among the male under the control and the female under the smell isolation and the control, noradrenaline levels decreased significantly after shinrin-yoku. Similarly, under the smell isolation, and the control, the male and female subjects showed significant decreases in the cortisol level. The NK cell activity of male and female subjects and had no significant change after shinrin-yoku. The BP, catecholamine level, cortisol level, and NK cell activity of male and female subjects showed no significant change after non-shinrin-yoku. The authors believe that this issue, and the general topic of shinrin-yoku and other environments with natural health benefits merit further study. It has been pointed out that the phytoncides and green forest environment in shinrin-yoku have a relaxing effect on the human body. As physical effects of shinrin-yoku, this study of male and female elderly subjects suggested the possibility of physiological effects in which appear within a short time and consist of multiple elements related to the human five senses, including the effects of phytoncides.   Future issues include accumulation of study results on the linkage between physiological/psychological responses and quantitative/qualitative data on odor and the visual sense.