Evaluating Cardiorespiratory Responses to Slow Breathing in Young Healthy Individuals: FitBit “Relax Mode” versus RESPeRATE

Device‐guided slow breathing has been tested in clinical populations (e.g., hypertension, type II diabetes) with the goal of reducing blood pressure (BP) via a sensitization of the baroreflex. The FitBit's “Relax Mode” and the RESPeRATE device are commercially available devices which acutely reduce an individual's respiration rate and, by extension, BP. To the best of our knowledge no studies have directly compared the cardiorespiratory effects of these devices. The purpose of this study was to compare acute respiratory and BP responses to the RESPeRATE device (RESP), the FitBit's Relax Mode (FB). We hypothesized that RESP would result in greater decreases in respiratory rate than FB, leading to larger decreases in BP. We evaluated the responses to a single bout of RESP (15 min) and FB (5 min) in young (mean±SD age: 23±1 y), healthy (BMI: 23±3 kg/m 2 ; mean arterial BP [MAP]: 82±8 mmHg) individuals (n=2 men, n=3 women). To normalize the duration of the stimuli, we compared the mean of the responses to FB to the mean of the last 5 min of RESP; the order of devices was randomized between subjects. Both devices were effective in reducing respiration rate from baseline (RESP: 11.1±3.5 to 5.6±0.7 breaths/min; FB: 11.2±1.8 to 7.3±0.3; main effect of slow breathing: p<0.01; effect of device: p=0.4). In contrast, tidal volume expansion increased from baseline during slow breathing (RESP: 0.70±0.33 to 1.41±0.50 L; FB: 0.61±0.17 to 1.20±0.59; main effect of slow breathing: p<0.01; effect of device: p=0.6). However, there was no change in minute ventilation from baseline levels (RESP: 7.0±1.8 to 7.8±3.0 L/min; FB: 6.7±1.8 to 8.7±4.2; main effect of slow breathing: p=0.1; effect of device: p=0.9), suggesting that the subjects did not hyperventilate during either slow breathing condition. MAP decreased from baseline during slow breathing (RESP: 82±8 to 80±8 mmHg; FB: 82±8 to 81±7; main effect of slow breathing: p=0.01; effect of device: p=0.9). Conversely, a significant slow breathing by device interaction (p=0.05) revealed that diastolic BP (DBP) was reduced from baseline only in the RESP condition (69±7 to 67±8 mmHg, p<0.01); FB was not associated with a reduction in DBP (69±8 to 69±8 mmHg, p=0.2). Our preliminary data indicated that while RESP reduced respiratory rate similarly to the FB, RESP may be more effective than FB at acutely reducing DBP in young healthy adults. Support or Funding Information This project was supported by a Natural Sciences and Engineering Research Council Discovery Grant (CWU). TEA & YC were supported by the McGill Department of Kinesiology and Physical Education Graduate Excellence Fellowship. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .