Breathing Protocol in Breath-hold Divers

Not Applicable

• Conditions: Exercise Training; Breathholding; Breathing Exercises; Apnea
• Interventions: Other: usual breathing (UB); Other: hook breathing removing nose-clip

• Registration Number: NCT04366414
• Lead Sponsor: Centro Universitario La Salle

Brief Summary

The aim of this randomized controlled trial study was to assess the effects of an 4-week exercise program on the recovery capacity after a voluntary maximal apnea. Participants will be randomly allocated to perform an experimental breathing protocol (NR-HB), or an usual training using their usual breathing (UB) protocol.

Detailed Description

It is a multi-center study. 2 different Spanish Freedivers Centres are included in the study (Madrid and Zaragoza).

Divers were randomly assigned to receive an experimental training (NR-HB) or to be included in the Control Group (UB).

The trial included two study visits. Each exercise training program will be applied sessions per week during 4 weeks. Participants received baseline assessments at the beginning of any intervention, and post-intervention assessments at the end of the fourth week.

Study Timeline

• Status Verified: 2020-04
• Study First Submitted: 2020-04-24
• Study First Submitted QC: 2020-04-27
• Last Update Submitted: 2020-04-27
• Study First Posted: 2020-04-28
• Last Update Posted: 2020-04-28
• Study Start: 2020-10-01
• Primary Completion: 2020-10-01
• Study Completion: 2020-12-14

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 46

Inclusion Criteria

• Absence of pain or illness
• No changes in cognitive ability
• Over 18 years old.
• Member of the Spanish Federation of Underwater Activities.
• Positive medical examination that allows the diver to practice voluntary apnea.

Exclusion Criteria

• People with systemic diseases, tumors, infections, pacemakers, history of epilepsy, hydrophobia, pregnancy women, pharmacological treatment.
• To be participating in other physical activities during the experimental research

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
usual breathing (UB)	usual breathing (UB)	It will apply a usual training program for 4 weeks, 4hours and 30 min per week distributed equally over 3 days in the week. In each session, it was performed 8 submaximes-dynamic apnoeas with 3-minute recovery between each one. Then was performed a maximal-dynamic apnoea. To finish the session, was performed a continuous training of free style swimming at moderate effort over 30 minutes.
hook breathing removing nose-clip	hook breathing removing nose-clip	It will apply a usual training program for 4 weeks, 4hours and 30 min per week distributed equally over 3 days in the week. In each session, it was performed 8 submaximes-dynamic apnoeas with 3-minute recovery between each one. Then was performed a maximal-dynamic apnoea. To finish the session, was performed a continuous training of free style swimming at moderate effort over 30 minutes. During that training, only this group will perform an experimental breathing protocol consisted of removing nose-clip previous to surface and then perform hook breathing during 20 seconds. This protocol was applied at the end of each of the 8 submaximes-dynamic apnoeas and after the maximal-dynamic apnoea

Primary Outcome Measures

Name	Time	Method
Oxygen Saturation change	Before and after training intervention (after 4 weeks)	Oxygen Saturation recovery will be record by the experimenters every 5 seconds by a handheld pulse-oximeter during the 1 min recovery time after a maximal dynamic apnea. The outcome was the length of the time to return to 95% SpO2 during the 1 min recovery time after maximal dynamic apnoea

Secondary Outcome Measures

Name	Time	Method
Heart Rate recovery	before and after training intervention (after 4 weeks)	Heart Rate will be record by the experimenters every 5 seconds by a handheld pulse-oximeter during the 1 min recovery time after a maximal dynamic apnea. The outcome was the length of the time to stabilize heart rate during these 1 minute.
Lung function (forced spirometry)	before and after training intervention (after 4 weeks)	The Spirometry will be perform according to American Thoracic Society criteria and was measured in litres. The maneuver will be perform 3 times and recording the best one.

Trial Locations

Locations (1)

Madrid FREEDIVERS association; 🇪🇸 Madrid, Spain