The purpose of this study was to observe the effect of training on morphological properties in the collagen fibers of tendons. Wistar strain rats at 7 weeks old were assigned to high speed endurance (H), moderate speed endurance (M), jump training (J) and control (C) groups. The amount of exercise for H group (speed at 30m/min for 60 minutes) and M group (speed at 17m/min for 75 minutes) was equalized according to the amount of oxygen consumed during training. As for the anaerobic training (J group), rats made high jumping form the standing position, wearing jacket with 50% of body weight, 50 times/day, which lasted for 4-5 minutes. The training period was designed for 5 days per week for 16 weeks.
The follwing is a summary of the results obtained:
1) Increases in fiber areas of both Slow-Twitch (ST) and Fast-Twitch (FT) fibers were observed in the H, M and J groups. The ST fiber area of H group was significantly larger than that of C group. Significant increase in FT fiber area was observed in both M and J groups.
2) Hypertrophy of collagen fiber in gastrocnemius muscle tendon was observed in Hand M groups; especially, M group showed much larger increase than H group. It tended to be greater for J group as compared with C group.
3) Collagen fiber area and diameter of tendon in plantar muscle were slightly larger for H and M groups relative to C group, but these differences were not significant.
These results suggested that both types of aerobic training induced hypertrophy in the collagen fibers of the tendons and increased the tensile strength; especially, the group which trained longer hours induced the higher effect.

Effects of treadmill running and restricted food intake on the metabolism of protein in several tissues were studied in male Wistar rats, aged 5 weeks and weighing about 100 g. Rats were divided into control group under free food intake (C), sedentary group under restricted food intake (Sr), exercise group under restricted food intake (Er), Food intake was restricted approximately to 66% of fed ad libitum for control group. Exercise program consisted of treadmill running for 60 minutes a day at 30 m/min on 6 days a week for 12 weeks.
A. The effects of sedentary under restricted food intake.
When compared with C
1) Lowering of body weight and increment in mg tissue/g body weight ratios. (M. Gastrocnemius, Liver, Brain, Testis, M. Soleus, M. Plantaris)
2) Significantly low level of protein content in gastrocnemius muscles, liver and kidney.
3) Inhibition in incorporation of ¹⁴C-amino acid mixture into brain and kidney protein in vivo.
B. The effects of exercise under restricted food intake.
i) compared with C
The effects were the same as those of Sr.
ii) compared with Sr
1) Lowering of body weight and increment in mg tissue/g body weight ratios. (Liver, Heart, Kidney, Testis)
2) Significantly low level of protein content in gastrocnemius muscles.
From this study it was suggested that, under the food restriction of long duration, the maintenance of protein content in brain in spite of the decrease of protein content in the other tissues indicated the existence of internal mechanism for life conservation in severe environment. And loaded with exercise under food restriction, protein content in gastra cnemius muscles decreased. Therefore, it was conceivable that skeletal muscles protein was consumed as energy for exercise.

Gender differences were measured in the amount of intramyocellular triglyceride (IMCL) and extramyocellular triglyceride (EMCL) in skeletal muscles using¹H-MR spectroscopy and their relation to body fat and peak VO₂was studied. Fourteen apparently healthy subjects were separated into groups by gender. Both the male and female group subjects were selected according to similar ages and BMI (male: n=7, BMI=20.5±0.6 kg/m², age=21.1±0.7 years, female: n=7, BMI=20.6±0.5 kg/m², age=18.7±0.3 years) . We found a significant correlation between IMCL and EMCL in the soleus (SQL: p<0.01) and medial gastrocnemius (MG: p<0.01) muscles. IMCL values in SQL were significantly higher than IMCL values in MG and tibialis anterior muscle (TA) in both males and females in the order of SQL>MG>TA (p<0.01) .
IMCL and EMCL values in MG and SQL among females were significantly higher (p<0.01) than their corresponding values in males. However, a gender difference in IMCL and EMCL values for TA was not found. There was no correlation between IMCL and EMCL values for each muscle and BMI ; but IMCL (r=0.63 in SQL) and EMCL (r=0.88 and r=0.73 in SQL, and MG, respectively; p< 0.01) values correlated significantly with percent FAT. There was no correlation between IMCL values for each muscle and peak VO₂; but the EMCL values of SQL correlated quite negatively with peak VO₂ (r=-0.63, p<0.05) . These results suggest that there are gender differences in intramyocellular and extramyocellular triglyceride contents. Lipids were positively related to percent body fat in SQL and MG; EMCL values may have a negative effect on endurance capacity.

Gender differences were measured in the amount of intramyocellular triglyceride (IMCL) and extramyocellular triglyceride (EMCL) in skeletal muscles using¹H-MR spectroscopy and their relation to body fat and peak VO₂was studied. Fourteen apparently healthy subjects were separated into groups by gender. Both the male and female group subjects were selected according to similar ages and BMI (male: n=7, BMI=20.5±0.6 kg/m², age=21.1±0.7 years, female: n=7, BMI=20.6±0.5 kg/m², age=18.7±0.3 years) . We found a significant correlation between IMCL and EMCL in the soleus (SQL: p<0.01) and medial gastrocnemius (MG: p<0.01) muscles. IMCL values in SQL were significantly higher than IMCL values in MG and tibialis anterior muscle (TA) in both males and females in the order of SQL>MG>TA (p<0.01) .
IMCL and EMCL values in MG and SQL among females were significantly higher (p<0.01) than their corresponding values in males. However, a gender difference in IMCL and EMCL values for TA was not found. There was no correlation between IMCL and EMCL values for each muscle and BMI ; but IMCL (r=0.63 in SQL) and EMCL (r=0.88 and r=0.73 in SQL, and MG, respectively; p< 0.01) values correlated significantly with percent FAT. There was no correlation between IMCL values for each muscle and peak VO₂; but the EMCL values of SQL correlated quite negatively with peak VO₂ (r=-0.63, p<0.05) . These results suggest that there are gender differences in intramyocellular and extramyocellular triglyceride contents. Lipids were positively related to percent body fat in SQL and MG; EMCL values may have a negative effect on endurance capacity.

This study used proton magnetic resonance spectroscopy (¹H-MRS) to investigate differences in muscle group specific intramyocellular lipid (IMCL) storage characteristics associated with elevated muscle lipid storage, and to determine whether IMCL content is associated with maximal aerobic capacity. Seven healthy men [untrained (UT)], four overweight (OW) and six endurance-trained (T) subjects volunteered for this study. Data were acquired, using ¹H-MRS, from the tibialis anterior (TA), medial gastrocnemius (MG) and soleus (SOL) muscles. The IMCL content in TA was approximately twice as high in T subjects than in UT and OW subjects. In MG, IMCL was higher in OW and T subjects compared with UT subjects. A linear relationship existed between the VO₂max and IMCL in TA and a curve of second-degree relationship between the VO₂max and IMCL in MG. These results suggest that elevated IMCL deposits in TA might reflect enhancement of aerobic capacity, whereas the IMCL accretion in MG might reflect not only aerobic capacity but also overweight and obese conditions in men.

The purpose of this study was to clarify some of the characteristics of race-walking, especially the relationship between walking speed and oxygen requirement, and stride in race-walking and normal walking, and to examine whether race-walking is effective for the maintenance and promotion of health.
The subjects were five male race-walkers (race-walker group) and five male college students (control group) .
The results obtained were as follows:
1. Under race-walk conditions, the highest speeds attained in the race-walker and control groups were 200-220 m/min and 160 m/min, respectively. Under normal walking conditions, however, the values were 140 m/min in both groups.
2. A lower oxygen requirement was observed at slower speed during normal walking and at a higher speed (over 130 m/min) during race-walking.
3. Oxygen requirement (ml/kg/100 m) in the race-walker group was minimal at 60-80 m/min during race-walking and at 60 m/min during normal walking. Values in the control group were minimal at 60 m/min under both walking conditions.
4. The oxygen requirement in the race-walker group was less than that of the control group under both walking conditions.
5. Under normal walking conditions, as the speed increased, both step-length and step frequency gradually increased, until step-length reached a limit of 80 cm. Thereafter, walking was maintained only by an increase in step frequency. However, in the race-walkes group, the subjects were capable of increasing their step-length further, and maintaining a higher speed (up to 220 m/min) .
6. It was suggested that race-walking is one of the most efficient exercises for maintaining and improving health.

The purpose of this study was to clarify some of the characteristics of race-walking, especially the relationship between walking speed and oxygen requirement, and stride in race-walking and normal walking, and to examine whether race-walking is effective for the maintenance and promotion of health.
The subjects were five male race-walkers (race-walker group) and five male college students (control group) .
The results obtained were as follows:
1. Under race-walk conditions, the highest speeds attained in the race-walker and control groups were 200-220 m/min and 160 m/min, respectively. Under normal walking conditions, however, the values were 140 m/min in both groups.
2. A lower oxygen requirement was observed at slower speed during normal walking and at a higher speed (over 130 m/min) during race-walking.
3. Oxygen requirement (ml/kg/100 m) in the race-walker group was minimal at 60-80 m/min during race-walking and at 60 m/min during normal walking. Values in the control group were minimal at 60 m/min under both walking conditions.
4. The oxygen requirement in the race-walker group was less than that of the control group under both walking conditions.
5. Under normal walking conditions, as the speed increased, both step-length and step frequency gradually increased, until step-length reached a limit of 80 cm. Thereafter, walking was maintained only by an increase in step frequency. However, in the race-walkes group, the subjects were capable of increasing their step-length further, and maintaining a higher speed (up to 220 m/min) .
6. It was suggested that race-walking is one of the most efficient exercises for maintaining and improving health.

The aim of this study is the evaluation of intramyocellular (IMCL) and extramyocellular lipids (EMCL) in skeletal muscle in elderly female endurance-trained individuals. The subjects comprised endurance-trained elderly persons (END : n=7, age=66.1±2.0) and healthy elderly control subjects (CON : n=7, age=70.1±3.0). All subjects were female and matched by age and lower BMI. We quantified differences in IMCL and EMCL concentrations in the tibialis anterior (TA), soleus (SOL), and medial gastrocnemius (MG) muscles using ¹H-MR spectroscopy. The IMCL and EMCL contents in SOL and MG in END were significantly lower than those in CON (p<0.01). Total lipid content in SOL and MG was lower in END. The IMCL and EMCL contents in TA in END were slightly lower than those in CON. Water contents of all types of muscle in END were higher than those in CON. These results suggest that stored IMCL and EMCL in END are less than in CON.