Proposal intensity adequacy of expiratory effort and heart rate behavior during the valsalva maneuver in preadolescents.

Background: When performing the Valsalva maneuver (VM), adults and preadolescents produce the same expiratory resistance values.

Objective: To analyze heart rate (HR) in preadolescents performing VM, and propose a new method for selecting expiratory resistance.

Method: The maximal expiratory pressure (MEP) was measured in 45 sedentary children aged 9-12 years who subsequently performed VM for 20 s using an expiratory pressure of 60%, 70%, or 80% of MEP.