As part of our Biohacking Masterclass Series, we will explore a number of different techniques and practices to improve your daily performance. This series will range from obvious subjects like exercise and nutrition to fringe subjects like breathing techniques and sleep hygiene.
Whether you are a full-time athlete or full-time working professional, the constant practice of optimizing your mind and body is a compounding investment. Incremental positive change every day results in radically higher performance returns over time. The relationship between the two is often synergistic, where your investment in your physical training leads to improvements in cognitive performance and vice versa. More recently, our personal pursuit of optimization has cast light on an imperative, yet often neglected facet of our daily performance: breathing. Fortunately, we live in a time of incredible scientific exploration, and numerous studies dive deeply into the ancient practices of yogic breathing to find out how well these exercises hold up to the scientific process. One such breathing technique is unbelievably simple yet has been shown to have profound results across a wide spectrum of performance metrics. From mental clarity and cognitive acuity to motor skill acquisition, alternate nostril breathing has transformative potential if added to your daily routine. [1-3]
What is it? How do you do it?
Similar to the way your body works on a sleep/wake cycle with your circadian rhythm, your nostrils actually operate on their own ultradian rhythm known as the nasal cycle. The nasal cycle is a process during which one nostril naturally becomes more efficient than the other. If you occlude one nostril right now, you may be able to see this in action. While the exact mechanism behind this process is not relevant to this article, each nostril’s activity is believed to have a direct effect on the activity in your autonomic nervous system. If you are breathing more heavily through your left nostril, research suggests there is increased activation of your parasympathetic nervous system (responsible for a calm, relaxed state). If you are breathing more heavily through your right nostril, the activation transfers to your sympathetic nervous system (responsible for the fight or flight response and heightened awareness). This cyclical transition from right nostril to left nostril dominance happens throughout the day and is completely natural. Yogic breathing exercises like alternate nostril breathing allow a ‘manual override’ of this nasal cycle to affect physiological and mental states. In other words, voluntary breath regulation can help you transition from sympathetic dominance to parasympathetic dominance, or a greater balance between the two. [1-3]
As the name implies, practitioners of alternate nostril breathing inhale and exhale through the left and right nostrils in a cycle. Using the thumb and index finger on your right or left hand, block your right nostril so that air cannot pass through and inhale exclusively through your left nostril; then, switch your fingers so that your left nostril is occluded, and exhale through your right nostril. Mirroring this process, inhale through your right nostril, switch your fingers to block your right nostril, and exhale through your left. Repeat the cycle all over again. The optimal ratios between breaths is a 2 second inhale, a 2 second hold, and a 4 second exhale. The optimal duration of this process is between 18 and 30 minutes. 
Effects on Performance
Beyond the numerous studies that have shown statistically significant improvements in blood pressure , a few researchers have investigated the effects of alternate nostril breathing on cognitive and physical tasks. In one such study, researchers were able to show that alternate nostril breathing went beyond cardiovascular effects and led to a statistically significant improvement in a timed mental vigilance test. Not only did the participant time decrease with a greater time of sustained attention, but the trend in responses showed a decrease in errors as well. 
In another study, researchers examined the impact of alternate nostril breathing on learning new motor skills. Immediately after participants were shown a new motor skill, they were either instructed to perform alternate nostril breathing or sit quietly for a period of time. Participants were tested immediately after completion of their designated task and again at 24 hours. In the alternate nostril breathing group, test performance at both intervals was significantly improved over control. The improvements seen in this study have particularly important implications in athletic environments, where faster retention times of new sport-specific skills can translate to a significant competitive advantage. 
Other researchers have shown that the benefits of unilateral breathing exercises include improved spatial and verbal task performance, increased pain thresholds, elevated mood, and positively influenced complex motor functions. Taken together, these studies have shown that alternate nostril breathing can be a significant addition to your morning and post-practice routines. [3-7]
- Telles, Shirley; Sadhana Verma, Sachin Kumar Sharma, Ram Kumar Gupta, Acharya Balkrishna. Alternate-Nostril Yoga Breathing Reduced Blood Pressure While Increasing Performance in a Vigilance Test. Med Sci Monit Basic Res. 2017.
- Kalaivani S, Kumari MJ, Pal GK. Effect of alternate nostril breathing exercise on blood pressure, heart rate, and rate pressure product among patients with hypertension in JIPMER, Puducherry. J Edu Health Promot. 2019.
- Yadav, Goldy; Pratik K. Mutha. Deep Breathing Practice Facilitates Retention of Newly Learned Motor Skills. Nature Scientific Reports. 2016.
- Busch, V. et al. The Effect of Deep and Slow Breathing on Pain Perception, Autonomic Activity, and Mood Processing — An Experimental Study. Pain Med. 2012.
- Jella, S. A.; D.S. Shannahoff-Khalsa. The effects of unilateral forced nostril breathing on cognitive performance. Int. J. Neurosci. 1993.
- Block, R.A.; D.P. Arnott, B. Quigley, W.C. Lynch. Unilateral nostril breathing influences lateralized cognitive performance. Brain Cogn. 1989.
- Roig, M.; K. Skriver, J. Lundbye-Jensen, B. Kiens, J.B. Nielsen. A Single Bout of Exercise Improves Motor Memory. PLoS One. 2012.