ABSTRACT
The purpose of this study was to investigate whether different modes of single-bout exercise would cause different responses in short-term bone metabolism. 24 untrained male college students (19.1 ± 0.1 years old) were recruited and randomly assigned to three groups: (1) a single-bout plyometric exercise group (the PL group, n = 8), (2) a 200-meter × 10 intermittent running group (the IR group, n = 8) and (3) a sedentary control group, which followed the same time schedule of experimentation without performing any exercise (the CON group, n = 8). Serial blood samples were collected before (baseline) and 5 min, 15 min, 1 h, 3 h, 6 h, 24 h, 48 h, and 72 h after exercise trials. Within 15 min of exercise, the PL and IR groups showed significantly higher serum phosphorus than did the control group (P < 0.05). Osteocalcin levels were significantly higher in the PL group at 5 min and 1 h after exercise (P < 0.05), while serum tartrate-resistant acid phosphatase (TRAP) showed no differences among groups. Exercises with different mechanical impact levels responded differently in serum bone formation markers as shown by osteocalcin. Because the increase in osteocalcin in the PL group was revealed shortly after the exercise bout, the changes might due to an exercise-induced mechanical impact rather than bone cellular activities.
