Inhibitory effect of electroacupuncture (EA) on the pressor response induced by exercise stress.

We examined the effect of EA on the exercise stress-induced pressor response in healthy adult subjects of both sexes. Each subject was subjected to a bicycle exercise test using a ramp protocol once/week for three or four weeks. Subjects were asked to perform the following tests in random order: 1) a baseline exercise test without EA and 2) exercise after acupuncture at P 5-6, LI 4-L 7 and/or G 37-39 acupoints. Brachial systolic (SBP), diastolic (DBP), and mean blood pressures (MBP), heart rate (HR) and the rate-pressure product (RPP, systolic BP x HR/100) were measured every three min, while a 12 lead ECG was monitored continuously. We observed increases in MBP, SBP, HR and RPP in all 17 subjects during exercise. In 12 of the 17 subjects (71 %), EA for 30 min before exercise, either at Jianshi-Neiguan acupoints (P 5-6) or Hegu-Lique acupoints (LI 4-L 7), led to an increase in maximal workload, and reduced peak SBP, MBP and RPP responses to exercise; EA did not alter DBP or HR responses in these subjects. EA at control acupoints (Guangming-Xuanzhong acupoints, G 37-39) in five subjects did not alter the hemodynamic responses. Seven additional subjects were enrolled to study the effect of EA during a bicycle exercise test using a constant workload. The results were similar, in five of the seven subjects SBP, MBP and RPP after exercise were attenuated significantly by EA at P 5-6. We conclude that EA at specific acupoints improves exercise capacity and reduces the hemodynamic responses in approximately 70% of normal subjects.