Yoga Breath Training to Improve Cardiorespiratory Synchrony in Spinal Cord Injury

The goal of this interventional study is to understand how regular yogic breathing practice, particularly a slow resistive yogic breathing technique called Ujjayi, would benefit individuals between the ages of 18 and 60 with spinal cord injuries. Previously yogic breathing has shown to improve respiratory function and sleep- we'd like to explore this further.

The main questions this study aims to answer are:

* How does Ujjayi breathing affect breathing patterns in individuals with spinal cord injuries?
* How does Ujjayi breathing affect lung function in individuals with spinal cord injuries?
* How does Ujjayi breathing affect the part of the nervous system responsible for ventilatory control in individuals with spinal cord injuries?
* How does Ujjayi breathing affect ventilatory perfusion (how well air and blood flow match in the lungs for efficient gas exchange) in individuals with spinal cord injuries?
* How does Ujjayi breathing affect sleep quality in individuals with spinal cord injuries?

Participants will undergo six weeks of training in Ujjayi breathing. Before and after this period, they will visit the lab for measurements of blood pressure, pulse, blood oxygen levels, and breathing. They will also perform several tests:

* Pulmonary function testing to assess lung capacity and respiratory muscle strength.
* Pace breathing frequency to four pre-recorded audio files at various breathing rates.
* Breathing exercises involving higher levels of carbon dioxide for a short time.
* Breathing exercises involving lower levels of oxygen for a short time.
* At-home sleep evaluation.

Between the two laboratory testing sessions, participants will practice yogic resistance breathing (Ujjayi breathing) for six weeks.

This study investigates the impact of a type of slow-resistive yogic breathing, Ujjayi Pranayama, on cardiopulmonary function in 20 men and women aged 18-60 with spinal cord injuries classified under the American Spinal Injury Association Impairment Scale (AIS) score of A, B, or C. Participants will undergo baseline and post-intervention laboratory assessments over six weeks at Spaulding Hospital Cambridge, with cardiovascular and respiratory measurements taken during controlled and uncontrolled breathing conditions. Ujjayi Pranayama training, focusing on resistance breathing during exhalation and inhalation, will include coaching sessions in weeks 1 and 4, supplemented by virtual support for home practice (\~20 min, twice daily). The study aims to determine whether regular yogic breathing practice enhances sleep quality, hypercapnic ventilatory response, and overall cardiopulmonary synchrony, potentially reducing respiratory and cardiovascular risks associated with SCI.

Eligibility Criteria:
Inclusion Criteria:

* Spinal cord injury
* American Spinal Injury Association Impairment Scale (AIS) score of A, B, or C
* Aged 18-60 years
* Wheelchair user
* Medically stable and able to follow directions
* Body mass index of 18.5 - 35 kg/m2

Exclusion Criteria:

* Resting blood pressure of \>140/90 mmHg
* Current use of tobacco or cardioactive medications (except medication to support blood pressure)
* Significant arrhythmia
* Bleeding disorder
* Pulmonary disease
* Coronary artery disease
* Diabetes
* Renal disease
* Cancer
* Epilepsy or other neurological diseases
* Current use of CPAP/BIPAP
* Has smartphone or device incompatible with the PranaTM application