Blood pressure decrease in elderly after isometric training: does lactate play a role?

This study aimed to investigate the effect of isometric handgrip (IHG) training on the blood pressure (BP) reduction in prehypertensive and hypertensive elderly people, and the possible role of lactate and redox balance. Thirty-three older (75.3±1.3 years old) were allocated to a non-exercise control (CG, n=11), prehypertensive (PHG, n=10), and hypertensive (HG, n=12) groups. PHG and HG performed a total of 8 sets of 1-min bilateral contractions at 30% maximal voluntary isometric contraction, each separated by 1-minute rest-pause. IHG training was performed for 8-week, 3 times a week on non-consecutive days. Systolic BP (SBP) and heart rate (HR) decreased post-training on PHG (-10 mm Hg; -5 bpm) and HG (-16 mm Hg; -9 bpm), respectively. Diastolic BP (DBP) decreased for HG only (-9 mm Hg) (P < 0.05). In addition, the decrease in BP occurred in parallel to a better redox balance and increased bioavailability of nitric oxide in PHG and HG (P < 0.05). Also, the variables that most present association to SBP decrease were capillary blood lactate concentration and muscle strength (P < 0.05). In summary, IHG training may be practical in improving clinical status of prehypertensive and hypertensive patients, by improving BP control, NO- bioavailability and redox balance. Further studies are required to elucidate the pathways of lactate concentration in blood-flow during exercise.