While our bodies burn a greater percentage of calories from
fat at lower intensities, we can actually burn a great deal of calories from fat at higher intensities simply because we burn more total calories both before and after a workout when we engage in higher intensity activities.
The fuel sources for aerobic cellular metabolism are fats and carbohydrates, with a greater percentage of calories coming from
fats at lower intensities.
Not exact matches
Do
at least 30 minutes of moderate -
intensity exercise every day and weight - train twice a week to
lower your percentage of body
fat.
Steady - state cardiovascular training — such as a 45 - minute jog performed
at about 55 to 65 per cent of maximum heart rate — causes the body to opt for a higher percentage of
fat for fuel and its
lower intensity means it can be performed over an extended period of time.
At lower intensities the body can efficiently use
fat as a primary fuel source.
A 2009 study conducted
at the University of St. Thomas by Dr. Daniel Carey, has discovered that during times of
low intensity, the body uses as much as 57 percent
fat calories and 43 percent carbohydrate calories.
«Although you burn a greater percentage of
fat calories (versus carbohydrates and protein)
at this
lower intensity, you also burn fewer overall calories than you would
at a higher
intensity,» he explains.
Multiple studies have shown that HIIT (High
Intensity Interval Exercises) are far more effective at burning body fat than lower intensity aerobic
Intensity Interval Exercises) are far more effective
at burning body
fat than
lower intensity aerobic
intensity aerobic training.
While a
lower intensity within a 55 to 60 % training heart rate zone would use a greater percentage of
fat for fuel, working
at a higher
intensity can nearly double the total calories burned in the same period.
At low intensities, you're burning mostly
fat and ketones for fuel so that your body could spare its muscle glycogen for higher
intensities.
The theory is that by maintaining a
low to medium level of
intensity at a steady pace, you will maximise your
fat burn.
When you do cardio
at a
low to moderate
intensity, the body's preferred fuel is glycogen (carbohydrate) first, and then
fats.
Muscle glycogen was modestly, albeit statistically non-significantly
lower after ketoadaption; however, ketoadapted athletes relied on a higher proportion of
fat oxidation to fuel performance as indicated by
lower RQ
at every level of exercise
intensity:
Increased
fat oxidation compensates for reduced glycogen
at lower exercise
intensities (eg, Zderic 2004), and ketoadaptation may do the same
at higher
intensities.
In real world terms it defined that
fat was only relegated to
low and mid-level
intensity of exercise and did not play a role
at higher aerobic
intensities as seen here:
So, running
at a
lower intensity will automatically make you burn more
fats, and the only real way to burn sugar is to go to a higher
intensity.
So if
low -
intensity for you means to be consuming 60 %
fats and 40 % sugars, but you can only make half of those sugars available (due to your LCHF diet), you can expect to run
at something like 80 % of your usual speed (accounting for the full 60 %
fats but only 20 % — half — the usual sugars).
There are 2 main reasons we can't: (1) it's impossible for the body to ingest calories
at a rate of 800 per hour while exercising — even ultrarunners who have trained this for a long time can only do 300 - 350, and they are burning calories
at a rate of say 1500 per hour --(2) the body is wired so that
at lower intensities you get more
fat - burning and
at higher
intensities you get more sugar burning.
They looked
at the charts and found that if you exercise
at a
low intensity and within a specific heart rate zone, then you'd burn proportionately more
fat.
This is because
fats are quite inefficient
at providing muscle energy to exercise
at high
intensity, and plenty of studies show high
intensity interval training (HIIT) decreases more body
fat than prolonged
low - to - moderate exercise training.
Your trainer was right that there is a higher percentage of
fat being burned than any other energy source during
low intensity steady state cardio, but did not take into consideration that while working
at a higher
intensity you actually burn more of every energy source (
fat and carbohydrates).
While exercising
at a
lower intensity will allow you to burn a greater proportion of calories from
fat, working out
at a higher
intensity means that you're burning more calories overall.
If you don't have a physically active job or aren't able to spend lots of time on your feet during the day, this
intensity is important for training the body to use
fat as a fuel, especially for individuals who compete in events lasting more than two hours.Although it will be difficult to keep your
intensity low on these days, if you've decided that you have lots of time on your hands and the type of training you want to do is primarily aerobic (vs. interval based training), then performing your endurance efforts
at a higher
intensity than Zone 2 will reduce the effectiveness of your harder workouts on subsequent days by fatiguing muscle and depleting carbohydrate stores in fast - twitch muscle.
Use your bluetooth - compatible HRM to train
at your
lower -
intensity MAF heart rate to burn more body
fat, improve health, develop endurance, and increase recovery.
Notice the
fat utilization
at low intensity of around 85 percent of total energy and 750 calories per hour — triple that of the levels he delivered on his first test!
Fat typically isn't used as energy until someone has been engaged in a high -
intensity activity for
at least 20 minutes — collagen can
lower this figure by a bit.
Nutrients get converted to ATP based on the
intensity and duration of activity, with carbohydrate as the main nutrient fueling exercise of a moderate to high
intensity, and
fat providing energy during exercise that occurs
at a
lower intensity.
Exercising
at this
lower intensity allows the body to use oxygen to help convert
fat to energy.
If exercising
at a
low intensity (or below 50 percent of max heart rate), you have enough stored
fat to fuel activity for hours or even days as long as there is sufficient oxygen to allow
fat metabolism to occur.
Burning calories
at low intensity for long periods of time activates
fat rather than burning glucose, so it will slowly chip away
at those
fat reserves.
Definition: the ability to move
at low - to - moderate
intensities for 90 + minutes (it's
at about the 90 minute mark when your glycogen levels become depleted and you must significantly begin to rely upon
fat as a fuel).
It has been experimentally demonstrated that
at lower exercise
intensity levels (i.e. below roughly 65 % of maximum heart rate for men or roughly 70 % of maximum heart rate for women)
fat is the dominant source of energy, but with increasing exercise
intensity carbohydrates gradually become the dominant source of energy for contracting muscles.
Although there is evidence that running is the best to develop your aerobic base (because you burn more
fats than in most other sports), whatever you can find that you can do
at a
low enough
intensity for prolonged periods of time will do the trick.
The reason is because in order to «shift gears» from burning
fats (
at a
low intensity) to burning sugar (
at a high
intensity), the body has to increase the stress hormones that up the heart rate.
The researchers also don't know whether the same benefits will accrue if you exercise
at a more leisurely pace and for less time than in this study, although, according to Leonie Heilbronn, Ph.D., a professor
at the University of Adelaide in Australia, who has extensively studied the effects of high -
fat diets and wrote a commentary about the Belgian study, «I would predict
low intensity is better than nothing.»
Start with
at least a month of foundation building
lower intensity longer exercise while you ingest a diet that is made up of increased
fat, protein, and decreased carbohydrates.
Otherwise her diet can remain relatively the same, if she has already shifted her diet and
low intensity training for a period of time that allowed her body to use
fat at higher
intensities.
Studies such as those conducted by scientists
at Laval University, East Tennessee State University, Baylor College of Medicine, and the University of New South Wales have all found that shorter sessions of high -
intensity cardio result in greater
fat loss over time than longer,
low -
intensity cardio sessions.
Now remember that
at low intensity aerobic workouts you'll burn more
fat than glucose but
at higher
intensity you end up burning more calories over the long run, which can lead to more
fat loss.