A Comparison of the Effect of 20- and 40-Min Session Durations of External Counterpulsation on Neuromuscular Function, Cortisol and Comfort in Physically Active Young Men

External Counterpulsation (ECP) is a well-established treatment for coronary disease, with interest growing in the potential to act as a sports recovery modality or pre-performance strategy. This pilot study compared the effects of different ECP durations upon neuromuscular function (NF), cortisol and subjective perceptions in a rested state.

Eleven physically active male volunteers received two ECP treatments (Renew Sport, Singapore) of differing duration (20-min and 40-min) in a randomised, repeated measures crossover design. Testing occurred pre-ECP, post-ECP, and 24-h post-ECP. NF testing comprised counter-movement jumps (CMJs) and 6-s sprint cycling. Saliva samples were analysed for cortisol. Rate of Perceived Exertion (RPE, 6 to 20) and Bipolar Comfort Scales (− 10 to 10) quantified participants' experiences, and ECP duration preference was examined. Repeated measures ANOVA and effect size (ES: Cohen's d) analysed NF and cortisol results. Paired t-tests analysed RPE and comfort ratings.

ECP demonstrated no effect, neither positive nor negative, upon NF outcome measures in both groups. A trend of reduced salivary cortisol levels across both groups following ECP was observed (P = 0.066). No RPE difference existed between groups. 20-min of ECP was rated as significantly more comfortable than 40-min (P < 0.05) and participants predominantly identified the 20-min ECP session as "more acceptable".

These results indicate that there were no effects for either duration upon the defined outcome measures, and thus, in these circumstances, no differences between the two durations were observed with respect to effects upon NF and salivary cortisol. The use of ECP warrants further investigation for potential benefits to performance before it can be proposed as an effective preparatory modality.