COAGULATION AND FIBRINOLYTIC RESPONSE TO EXERCISE, COLD, AND EXERCISE WITH PRIOR COOLING.

摘要

Ten male student volunteers (mean age, 27.1 years) participated in this investigation to determine if exercise and cold stress could differentially effect coagulation and fibrinolysis. Euglobulin lysis times (ELT) and partial thromboplastin times (PTT) were used to assess fibrinolytic activity and coagulability, respectively. Cold and neutral environmental conditions were established at 5(DEGREES)C and 28(DEGREES)C. Exercise consisted of pedaling a bicycle ergometer at 300 kgm(.)min('-1) for five minutes followed by ten minutes at 900 kgm(.)min('-1). The testing schedule was as follows:;rest exercise.;Session A (Cold): PC CR CE.;rest exercise.;Session B (Neutral): PN NR NE.;Time (mins) 60 15.;ELT, PTT, and hematocrit (HCT) was assessed at PC, pretest-cold;;CR, cold-rest; CE, cold-exercise; PN, pretest-neutral; NR, neutral-.;rest; and NE, neutral-exercise. Mean weighted skin temperatures.;(T(,sk)) and rectal temperatures (T(,re)) were assessed at 15-minute(' ).;intervals throughout.(' )T(,sk) dropped continuously during cold exposure (CR, CE) but was relatively unaffected under neutral conditions. T(,re) response to cold was more complex, exhibiting an initial increase followed by a decrease with continued exposure. T(,re) increased in response to exercise at 28(DEGREES)C but exhibited no change at 5(DEGREES)C. ELT was reduced to 74, 62, and 44% of pretest values for CR, NE, and CE, respectively. No difference was found to exist between groups for PTT. HCT was increased to 107, 107, and 111% of pre-test values for CR, NE, and CE, respectively. These data suggest that coagulation and fibrinolysis may be affected differentially in response to exercise, a result that speaks in favor of exercise-induced fibrinolysis as a prophylaxis for atherosclerosis.