Students and general long distance runners carried out 1600m run for 24 hours and their physical functions were measured with lapse of the relay. Following results were obtained.
1) Prolongation of mean running time of student long distance runners in 1600m runs appeared at about 8th-10th runs, 12.8-16.0km, but that of general long distance runners did at 5th-6th runs, 8-9.6km.
2) There was plus correlation between mean of running time and its standard deviation in 1600m runs. It was r=0.55 and its regression equation was Y=0.58X-162.3. But these of general long distance runners were r=0.53 and Y=0.358X-97.3, respectively.
3) Decreased body weight from 1st-8th run was great and succesive, and occupied about 30%-70% of final decreased body weight. Thereafter, increase or decrease of the body weight was repeated and the time course became slow. There were some runners who showed large and succesive decreased body weight with the runs through the competition. The decreased body weight during the competition was influenced by the wind velocity, which supressed it considerably.
4) Heart rate of a student long distance runner during 1600m run reached 180-189 beats per minute every run. Resting heart rate of general and student long distance groups showed circadian rhythm during the competition, but that of student runners was higher through the competition and their systolic pressure shows a tendency to below in later period of the competition.
5) Threshold of knee jerk was low in the initial few runs and thereafter showed circadian rhythm. Reaction time to light was also facilitated in the initial runs and there-after prolonged about 30msec and maintained till the end of the competition. Frequency of subjective symptoms increased with number of the runs. At middle of the competition, it came over Sakai's standard and the A, B and C symptoms at the end of the competition were 33.0%, 20.0% and 25.0%, respectively.
6) Calorie intake per day of the student long distance runners was in the range of 1240-2540Cal. Total energy consumption was estimated 7457Cal. per day.
7) Blood glucose of the student long distance runners mostly unchanged through the competition, but serum triglyceride and total phospholipids significantly decreased and inversely serum free fatty acids prolongly mobilized.