Based on the maximal oxygen intake (VO₂max), 24 male students were classified into high (H-G), middle (M-G) and low (L-G) groups of the VO₂max level. In each VO₂max level group, thermoregulation characteristic values during cold exposure at an ambient temperature (Ta) of 12°C were compared with several parameters of cold-induced vasodilation (CIVD) measured at 28°C (observation 1) and the parameters measured after 30 min from the start of 60-min cold exposure (observation 2) . The relationship between CIVD as a peripheral vasomotor regulation response, and autonomic thermoregulatory response was examined. The results are as follows:
A . H-G showed the smallest decreases in the rectal temperature (Tre) and in mean skin temperature (Tsk), and these parameters decreased as VO₂max decreased. Enhancement of metabolic heat production (M) was highest in H-G and lowest in L-G.
B . In the observations 1 and 2 of the CIVD tests, mean skin temperature (MST), temperature at first rise (TFR) and resistance index (RI) increased with rise in VO₂max, while time of temperature rise (TTR) decreased. In the observation 2, TFR remained low by decreased temperature before water immersion (TBI) and, with TBI taken into consideration, no significant change in RI was observed except only in L-G.
C. MST, TTR and RI in the CIVD measurements (observation 1 and 2) were significantly correlated with the mean thermoregulation characteristic value during 30-60 min after the start of cold exposure (the second half period) .
D. During the second half period of cold exposure, significant negative correlations were observed between Tsk and body fat% (BF%) and between M and BF %. VO₂max was significantly correlated with RI, Tre, Tsk and M.
These results indicate that difference in physical fitness for endurance is clearly reflected in the values of cold-induced vasodilation in thermoneutral zone and during cold exposure. The peripheral vascular resistance of finger increased during cold exposure from that in thermoneutral zone causing decrease of finger skin temperature. After that, due to hunting reaction, the peripheral vascular resistance decreased, and a correspondance was observed between effectiveness in raising finger skin temperature through increase in skin blood flow and physical fitness for endurance. An interrelation was observed between the local cold resistance of peripheral vasomoter during exposure of finger to ice water and the whole cold resistance of autonomic temperature regulation during cold exposure of the whole body. It may be inferred that the subjects with high physical fitness for endurance have low insulative of body fat but have good cold tolerance by enhancement of heat production and preservation of skin temperature.

Cold-induced vasodilation (CIVD) and heat-induced vasoconstriction (HIVC) were examined in 8 Germans who were living in the suburban areas of the central Germany and 7 Japanese who were staying in the suburban areas of central Germany for the mean length of 2.7±0.6 years. CIVD were measured during the middle finger immersion in cold water at 0.2°C for 30 minutes. The finger blood flow for HIVC was measured by laser Doppler flowmetry (LDF) in water from 35°C to 43°C every 10 minutes. HIVC represented as the percentage of the LDF volts after immersing as compared with the values before immersing (finger blood flow %, FBF%) . The daily energy intake of the subjects were also investigated.
The mean skin temperature and the resistance index as a value of CIVD were significantly higher in the Germans than Japanese, but the values of the Japanese living in Germany were higher than those of the Japanese living in Japan. The HIVC appeared at 35°C and 38°C and FBF% was the lowest at 40t both in the Germans and the Japanese. The finger skin temperature increased during jmmersion in both groups but was significantly higher in the Germans at 43°C. The decrease in FBF% per minute and the increase in the finger skin temperature per minute at 38°C and 40°C were greater in the Germans. The increase in FBF% per minute was greater in Japanese but the increase in finger temperature per minute were smaller in Japanese at 43°C. The daily protein intake of the Japanese living in Germany was higher than the average intake of the Japanese living in Japan, and their daily protein intake per body weight was approximately equal to that of the Germans.
It is inferred that CIVD is affected by the living circumstances and the state of nutritional intake, and HIVC by the thermal sensation and also by the living circumstances.

The effects of exercise on cold-induced vasodilation (CIVD) as an index of local cold tolerance caused by a shift in the core body temperature in the follicular and luteal phases to a lower level were evaluated in athletes and non-athletes. The subjects were healthy female students with a normal menstrual cycle, who consisted of 15 athletes and 9 non-athletes. The percent body fat was lower, and the maximal oxygen intake was significantly higher in the athletes than in the non-athletes. The difference in the basal body temperature between the follicular and luteal phases differed significantly (P<0.01) between the athletes (0.53±0.221) and the non-athletes (0.88± 0.26t) . CIVD was measured once in the late follicular phase and once in the midluteal phase in the spring of 2002. Finger skin temperature before ice water immersion did not differ between the follicular and luteal phases in the athletes or non-athletes. The mean finger skin temperature was higher in the luteal phase in both the athletes and non-athletes. Similarly, the temperature of the first rise was higher, and the time of temperature rise was shorter, in the luteal phase. The resistance index was 11.47±2.36 in the follicular phase and 13.40±1.45 in the luteal phase in the athletes, and 10.44±3.21 and 11.89±2.09, respectively, in the non-athletes. It was significantly higher in the luteal phase in the athletes but showed no significant difference in the non-athletes. In addition, it was significantly higher in the athletes than in the non-athletes in the luteal phase, but no difference was observed between the two groups in the follicular phase. These results suggest that the finger skin temperature during ice water immersion was maintained at a higher level in the athletes than in the non-athletes despite the greater reductions in the basal body temperature in the luteal phases in the athletes ; this is because of suppression of cutaneous vasoconstriction and an increase in collateral blood flow. Moreover, cutaneous vasodilation induced by the axon reflex of sensory nerves, release of histamine substances, reduction of vascular sensitivity to catecholamines, or release of vasodilators is considered to be a mechanism of the higher resistance index in the athletes.

A study was conducted to evaluate the physique, body composition, ⁴⁰K (body potassium content; K) and skinfold thickness of severely handicapped children and adults. Seventy-two subjects were classified by physical activity level into four categories, and these categories were combined into an ACTNE GROUP and an INACTIVE GROUP.
The handicapped children and adults were evaluated for body height, body weight, percentage body fat (skinfold method and ⁴⁰K method), lean body mass (LBM), K (g), K/Wt (g/kg), and skinfold thickness, all parameters being measured in 1985. The parameters were compared with values found between males and females, cerebral palsy (CP) and mentally retarded (MR), and the active group (AG) and the inactive group (NG) .
The following mean values were recorded: ACTNE GROUP (AG) , age 16, 9 yr; height 132.5 cm; weight 27.9 kg; percentage body fat %Fat (Nagamine) 17.8%; %Fat (Forbes) 31.2%; LBM 22.7 kg; K (g) 49.3 g ; K/Wt (g/kg) 1.79 g. INACTIVE GROUP (NG) , age 17.0 yr; height 132.7 cm; weight 22.9 kg ; percentage body fat %Fat (Nagamine) 15.6%; %Fat (Forbes) 35.2%; LBM 19.1 kg; K (g) 36.5 g; K/Wt (g/kg) 1.68 g.
The values of body composition (%Fat, LBM) estimated using the formulae of Forbes, Garrow and Behnke, by the ⁴⁰K method were compared with those estimated by the skinfold method (Nagamine) .
Results for physique, percentage body fat, LBM (kg), K (g) and K/Wt were compared between males and females, CP and MR, and AG and NG. One of the most outstanding characteristics of handicapped AG was that body weight, LBM (kg) and K (g) were greater than in handicapped NG.