An athlete should focus primarily on breathing to improve his/her performance.
Indeed, to warm-up, stretch and improve one’s physical condition are not the only criteria responsible for the results of an athlete. If the whole body is not properly oxygenated, it will quickly reach limits that can result in shortness of breath, stiffness, side aches, even injuries.
The role of nasal breathing is to maintain the naturally balanced circulation of air in our body. And so, provide enough oxygen to our muscles to allow us to recover more quickly from an effort and gain endurance.
There are many benefits to Nasal Breathing:
1) Sleep: Improved quality of sleep and reduced snoring.
2) Performance: Increase in V02Max as you are optimizing nasal breathing.
3) Strength: Allowing you to push yourself beyond your comfort zone so that you may benefit from extra repetitions at the end of your workout.