Effects of exercise and exercise conditioning on blood platelet function.
The effects of exercise and exercise conditioning on blood platelet function were investigated in six healthy individuals who had not engaged in regular exercise for at least 1 yr prior to the study. The subjects (three men and three women) had a mean age of 28 (range 23-32) and participated in a supervised program of treadmill exercise. Subjects exercised for 20 min, three times weekly, for 12 wk at 70-80% of estimated maximum heart rate. Samples for platelet counts, platelet aggregation, and plasma beta-thromboglobulin (beta-TG) were obtained prior to training and after 6 and 12 wk of training. All subjects responded with an increase in aerobic capacity during training. Resting mean systolic and diastolic blood pressures decreased after training (P less than 0.05). Platelet counts increased after exercise, and the increment in week 12 exceeded that in the 1st wk by 57%. Platelet aggregation studies in platelet rich plasma (PRP) showed an increase in slope after exercise (week 1, P less than 0.05) which decreased with training (week 1 vs week 12, P less than 0.01). Aggregation studies utilizing impedance aggregometry in diluted native whole blood showed an acceleration of both spontaneous aggregation (P less than 0.01 weeks 6 and 12) and aggregation using epinephrine as an agonist (P less than 0.05) following exercise. Plasma beta-TG levels did not increase significantly after exercise; however, resting concentrations of beta-TG decreased with training (P less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
Davis
R B
RB
Department of Internal Medicine, University of Nebraska Medical Center, Omaha 68105.
Boyd
D G
DG
McKinney
M E
ME
Jones
C C
CC
D000328:Adult; D001792:Blood Platelets / Q000502:physiology*; D005069:Evaluation Studies as Topic; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010806:Physical Education and Training; D010974:Platelet Aggregation / Q000502:physiology*; D001620:beta-Thromboglobulin / Q000502:physiology*
D001620:beta-Thromboglobulin