Combating Motion Sickness

What causes motion sickness? The main reason is that during certain kinds of involuntary motions the brain receives conflicting neural signals from visual receptors in the eyes, positional receptors in the inner ears and in muscles and tendons, and gravity receptors in the stomach. These conflicting signals confuse the brain, and nausea ensues.

Recently, researchers learned that the severity of motion sickness caused by a slow, cyclic motion can be reduced by deliberately breathing out of sync with the motion. Breathing either faster or slower than the cyclic motion allows the diaphragm to counteract the heaving movements of the stomach, thereby minimizing the neural disconnect between stomach gravity sensors and other motion and position receptors. The worst thing you can do is to take a breath with each heaving motion, although it’s the natural thing to do.

Reference: Denise, P. et al. Effect of temporal relationship between respiration and body motion on motion sickness. Autonomic Neuroscience 151:142-146, 2009.