Abstract
Background: Whilst resistance training has been proven to convey considerable benefits to older people; immediately post-exercise there may be elevated transient risks for cardiac events and falls. Objectives and Measurements: We assessed the acute effects of eccentrically-biased (EB) and conventional (CONV) resistance exercise on: platelet number, activation and granule exocytsosis; and mean velocity of centre of pressure displacement (Vm). Design, Setting, Participants and Intervention: Ten older adults (7 males, 3 females; 69 +/- 4 years) participated in this randomised controlled cross-over study in which they performed EB and CONV training sessions that were matched for total work and a control condition. Results: Immediately postexercise there was a statistically significant difference in platelet count between the control condition, in which it had declined (pre 224 +/- 35 10(9)/L; post 211 +/- 30 10(9)/L: P < 0.05) and CONV in which it had increased (pre 236 +/- 55 10(9)/L; post 242 +/- 51 10(9)/L: P > 0.05). There was no change in platelet activation and granule exocytsosis or Vm following EB and CONV. Conclusions: Overall, while minor differences between regimens were observed, no major adverse effect on parameters of platelet function or centre of pressure displacement were observed acutely following either regimen. Eccentrically-biased and conventional resistance exercise training regimens do not appear to present an elevated acute risk in the context of changes to platelet function contributing to a cardiac event or postural stability increasing falls risk for apparently healthy older adults.
