As a fitness trainer, I teach key principles to my clients: proper form, isolation and breathing. Although I see people trying to maintain good form or concentrate on isolation, it amazes me how one forgets to breathe during their training session. Why does it really matter? Proper breathing during exercise helps in a few important ways. It makes cardiovascular training more efficient, helps with power and stability during strength and endurance training, and it fosters relaxation during mind/body and flexibility training.

Here are the key principles of knowing how and when to breathe during exercising:

Cardio training -- When performing cardio training, such as running, cycling or swimming, it is important to remember that breathing and the cadence of the cardio activity may not always be in sync. For example, when running up a hill, you may be running a bit slower, but your breathing rate may be high.

The most important thing to remember is avoiding shallow breathing during cardio training. Shallow breathing is an indicator that you are either working too hard or have not established a good breathing pattern for the activity you are doing. Try taking stronger, deeper breaths during cardio training (without any feeling of holding your breath), and establish an inhale/exhale pattern that feels comfortable for you. For example, many runners will inhale once during three foot strikes in a row (right, left, right), and then exhale once during the next two foot strikes (left, right).

Strength/endurance training -- When doing strength or resistance training, such as weight lifting, you should generally exhale on the exertion (or most difficult part of the exercise) and inhale on the recovery (easiest part of the exercise). For example, when doing a crunch, you should exhale when you lift your shoulders off the ground, and inhale when you lower your shoulders to the ground

Relaxation -- When performing mind/body, stress reduction or flexibility training, such as yoga, you should generally focus on deeper, longer diaphragmatic breathing that will not only help you execute the moves more deliberately, but will also help you relax and focus on the exercises while reducing stress.

Diaphragmatic breathing is intended to help you strengthen the diaphragm, decrease the work of breathing by slowing your breathing rate, decrease oxygen demand and use less effort and energy to breathe. This type of breathing is marked by expansion of the abdomen rather than the chest when breathing, and is done with slow intakes of air, allowing the body to absorb all of the inhaled oxygen.

Author's Bio: 

Aaron Savvy is an accomplished certified American College of Sports Medicine (ACSM) trainer whose specialties include core strengthening, weight training, agility, balance/stabilization, coordination, explosive training, motivation and rehabilitating injuries.

In addition to personal training Aaron has competed in the FX circuit fighting competition FX
Original ToughMan. He has written for several fitness publications and has recently published the Savvy Eating eBook. Aaron is currently working on his upcoming eBook the "F Factor" which outlines the key to mastering and dominating fitness challenges. In addition to being an author Aaron has given seminars on health, wellness, and motivation.

For more questions visit http://www.aaronsavvy.com or follow http://twitter.com/savvyfit