(DGIwire) – People exercise for many different reasons. If the objective is to encourage fat burning and optimal health, intensity is an important consideration.
Is there such a thing as a fat burning heart rate or intensity? That depends on whom you ask. Some say yes, while others say no, while others say maybe or sometimes. Among those who say yes, there is disagreement when it comes to the intensity level that will yield the best results. Does it really make any difference?
If your primary objectives are fat-loss and optimal health, the answer is yes.
To start, during any activity, regardless of intensity, you are burning a mix of fat and glucose. There are intensity levels, usually corresponding to heart rate levels, that result in a higher percentage of fat being used for fuel. The ability to use more fat for fuel can be improved with proper training and provides several exercise and health related benefits.
Tests show that the fat/sugar mix changes with intensity levels. The intensity at which the highest amount of energy comes from fat is often referred to as the aerobic threshold. Fat burning continues to rise up to this point and then falls off as the intensity becomes more anaerobic, requiring a greater percentage of glucose.
This mix is also highly individualized based on the person’s level of fitness and proficiency for a given activity. The same person will even have different ideal intensity levels for different activities.
When it comes to optimal health, intensity levels matter because all activity levels above resting are perceived as a form of stress. This stress can be good or bad. It depends on the intensity level and duration of the activity. Exercise stress is generally good up to a point. Ideally, you would like all of your activities and exercise sessions to be perceived as good stress.
How can a person know the ideal level for them?
A metabolic test is the most accurate way if you can have it done while you are performing the specific activity or exercise of choice. This is also the most expensive and inconvenient method.
There are several different calculations based on heart rate that are often used that will get close. However, these are only a generalized estimate and still depend on the activity and your proficiency.
“The simplest way, which can be used for all activities, is paying attention to your breathing. Nasal breathing, or breathing only through your nose, is a good indicator for knowing when your body is switching from aerobic (fat burning) to anaerobic (sugar burning). As long as you can still breathe exclusively in and out through your nose, you can be confidant that the stress level or intensity is not too high,” according to Tom Griesel, co-author of TurboCharged: Accelerate Your Fat Burning Metabolism, Get Lean Fast and Leave Diet and Exercise Rules in the Dust .
Nasal breathing may seem unusual or unnatural at first. However, it should be noted that humans are really the only mammals that resort to mouth breathing during increased levels of activity. Take a look at a thoroughbred race horse at full gallop and you’ll see nostrils flared and open wide even at full throttle. With consistent practice, we too can increase our level of intensity while maintaining nasal breathing.
The necessity to switch from nasal breathing to mouth breathing at a certain intensity level corresponds closely to your maximum aerobic threshold as well as your maximum beneficial stress level. Maintaining nasal breathing ensures maximal fat burning as well as having a restorative effect on your body. If you’re used to pushing through your exercise sessions, this method/intensity might seem too easy. At first, you will probably find it very hard to maintain at your usual intensity without resorting to mouth breathing.
Griesel adds, “Monitor your breathing during exercise. If you begin to exceed your ability to breathe through your nose, slow down until you can resume nasal breathing. Over time, you will train your body to utilize fat at higher and higher levels of exertion (at a lower heart rate). Training this way will enhance your ability to use more fat for fuel 24 hours a day and keep stress levels optimal.”
From now on, consider nasal breathing to be reflective of your ideal and a switch to mouth breathing as a “fight or flight” stress signal telling you to slow down.
Athletes should try to utilize nasal breathing almost exclusively during training time to consistently develop and increase their aerobic, fat-burning metabolism, resorting to mouth breathing only during limited speed-work or when needed in competition.