Researchers therefore investigated whether vibration stimulus applied through air as it passes into the airways elicits increments of maximal breathing performance.

Methods

12 healthy subjects (8 female, 4 male; 22-50 years old) were recruited from University staff and students and they completed 3 maximal inspirations followed by 10 inspirations against you breathe vibration stimulus (VIB), an inspiratory resistive-load training device (RES) or resting breathing (CON; no load). 3 forced inspirations were repeated and compared to pre-training for maximal breathing power.

Results

Maximal breathing power was significantly greater (15%) after 10 breaths of vibrated resistance (VIB) when compared to PRE (VIB) and POST control (CON) and POST resistive-loading training device (RES). There was no effect of either resistance or control breathing on maximal breathing power.

Discussion

10 breaths of vibration lead to increased maximal breathing power suggesting that applying a vibration stimulus increases the voluntary force generating capacity of the inspiratory muscles, in a similar manner observed when vibration is applied to other skeletal muscles (Mileva et al., 2006). The mechanisms underlying the changes in maximal breathing power require further study, however mechanisms such as shifts in neuromuscular recruitment via increases in stretch reflex sensitivity may have a role (Cardinale, 2003). This would enhance recruitment of higher-threshold motor units and the activation of previously inactive motor units. Confirmation of the mechanisms involved will require the acquisition of respiratory muscle EMG, transcranial magnetic stimulation and testing of peripheral reflexes.

Thus, vibration leads to an increased maximal breathing power suggesting there is an increase in neural inspiratory drive possibly via upregulation of the respiratory motoneurones. The benefits of this facilitation could lead to increases exercise performance and as a warm up device.

Dr Paul Sumners is a neurophysiologist at London South Bank University. His expertise is learning and memory of respiratory and skeletal muscle systems, and performance improvement. He is also an inventor of vibration training related devices whose benefits are being applied to elite athletes and clinical populations. His personal blog is http://vibrotraining.blogspot.com