Effect of Acu-TENS on recovery heart rate after treadmill running exercise in subjects with normal health

SummaryObjectiveThis study aims to investigate the effect of transcutaneous electrical nerve stimulation, applied at bilateral acupuncture points PC6 (Acu-TENS), on recovery heart rate (HR) in healthy subjects after treadmill running exercise.DesignA single blinded, randomized controlled trial.SettingLaboratory with healthy male subjects (n = 28).InterventionsEach subject participated in three separate protocols in random order.Protocol AThe subject followed the Bruce protocol and ran on a treadmill until their HR reached 70% of their maximum (220-age). At this ‘target’ HR, the subject adopted the supine position and Acu-TENS to bilateral PC6 was commenced.Protocol BIdentical to protocol A except that Acu-TENS was applied in the supine position for 45 min prior to, but not after exercise.Protocol CIdentical to protocol A except that placebo Acu-TENS was applied.Main outcome measuresHeart rate was recorded before and at 30 s intervals after exercise until it returned to the pre-exercise baseline. The time for HR to return to baseline was compared for each protocol.ResultsAcu-TENS applied to bilateral PC6 resulted in a faster return to pre-exercise HR compared to placebo. Time required for HR to return to pre-exercise level in protocols A–C was 5.5 ± 3.0; 4.8 ± 3.3; 9.4 ± 3.7 min, respectively (p < 0.001). There was no statistical difference in HR recovery time between protocols A and B. Subjects expressed the lowest rate of perceived exertion score (RPE) at 70% maximum HR with protocol B.ConclusionThis study suggests that Acu-TENS applied to PC6 may facilitate HR recovery after high intensity treadmill exercise.