Not necessarily. Whether your burning glucose or fat depends on the intensity level of the exercise you`re performing, not your glycogen levels. i.e. A person can have very low glycogen levels and even be depleted of glycogen, and may not be burning fat efficiently if they are exercising beyond their aerobic capacity. (aerobic vs anaerobic). Your body will break down muscle to fuel anaerobic activity without adequate glycogen. This is why HIIT is a definite no-no when you are on a ultra-low carbohydrate diet. When eating ultra low carb, stick to steady-state aerobic cardio, which burns fat for fuel. If you`re doing HIIT, eat your carbs.
Also, it`s a fallacy that you are carb-depleted in the mornings after a night of sleeping. The average person has 300gms of glycogen stored in their muscles and in their liver. A level of glycogen that would need considerably more than 8 hours to deplete. Around the 48-72 hour mark is where the average sedentary person starts to deplete their glycogen stores.
This is all correct. The early morning, fasted cardio BURNING pure fat idea is largely bro science / myth. It's not backed up my any real studies or data. I dont have time/desire to dig it all up and spoon feed you. Its all about daily calories in / calories out over time and the makeup (macros) of those calories that dictate body composition. Cardio AT ANY time helps with this. The idea that doing it in the morning is magical is myth. I lot of people do it just because its an ideal way to break things up but there is very little evidence that it truly makes you leaner. Anecdotal reports seem abundant though which just goes to show you're all fucking idiots.
Strength and Conditioning Journal by Brad Schoenfeld, MSc, CSCS
Here are the cliffs for you lazy mouth breathers that learned everything you know from flex magazine:
-research has shown no difference in total fat loss between subjects doing fasted cardio and those doing cardio after eating.
-fat burning consists of 1) liberating fatty acids from adipose tissue through lipolysis and then transport of those fatty acids to other tissues like muscle, liver, heart where they are then 2) oxidized for energy. When you eat before cardio you reduce lipolysis but it ends up not making a difference because lipolysis is NOT the rate limiting step of fat loss when it comes to cardio, it is oxidation that is rate limiting so you end up oxidizing the same amount
-you may burn MORE fat over a 24 hour period when you eat beforehand because there is a GREATER thermogenic response to cardio as opposed to eating fasted
-Lemon et al. demonstrated nitrogen losses were DOUBLED when you train fasted. Fantastic for maintaining muscle in a caloric deficit... NOT
-not eating before cardio will reduce training intensity and means you will burn less calories during cardio because you won't have as much energy.
In conclusion, the literature does not support the efficacy of training early in the morning on an empty stomach as a tactic to reduce body fat. At best, the net effect on fat loss associated with such an approach will be no better than training after meal consumption, and quite possibly, it would produce inferior results. Moreover, given that training with depleted glycogen levels has been shown to increase proteolysis, the strategy has potential detrimental effects for those concerned with muscle strength and hypertrophy. Schoenfeld, Brad. Does Cardio After an Overnight Fast Maximize Fat Loss. Strength and Conditioning Journal. 2010
Paoli et al. Exercising Fasting or Fed to Enhance Fat Loss? Influence of Food Intake on Respiratory Ratio and Excess Postexercise Oxygen Consumption After a Bout of Endurance Training. International Journal of Sport Nutrition and Exercise Metabolism. 2011
Whitney E, Rolfes S. Understanding Nutrition. 13th edition. 2013
Gropper SS. Advanced Nutrition and Human Metabolism. Sixth edition. 2013If it were not for the divine light givers such as myself and Rudee, you fucking meatheads would continue living in the dark for ages. Getting up at 5am for your grueling and exhausting (and pointless) fasted AM cardio. Fucking miserable.ROGER FUCKING BACON FREE YOUR MIND!!!!
