“Fasted cardio, does fasted cardio help you lose fat faster?” One of the most controversial topics in fitness industry.
Few coaches and fitness Guru’s consider it as a quick way to lose fat and some thinks that it is a bullshit idea to train in a fasted state since you are going to lose muscle in this process.
Let’s see how the idea of fasted cardio comes into picture and the claims by the fitness guru’s about fast fat loss is right or wrong?
The argument in favor of fasted cardio is that since your body is deprived of carbohydrate and insulin levels are low, Body will use fat as a primary source of energy.
It sounds true and research has supported this idea.
First research held in 1976 has shown that if you consume carbohydrate during cardio session your body will use carbohydrate as a fuel during workout and less fat as a source of fuel. (1)
Another research held in 2010 has shown that Training with limited carb availability increases use of fat as a preferred source of energy. (2) (3)
One more research study few year back has shown that fat oxidation during aerobic exercise performed in fasted state was more compare to exercise performed in fed state. (4)
Till this point you must be thinking that Fasted cardio is best for fat loss since these studies focused on utilization of fat as a fuel during exercise (Fat burned during exercise), But, wait! bigger picture is yet to come.
All the above researches have just calculated the fat used as source of fuel during workout, But what about overall fat burnt during whole day?
A research held by Paoli and his team at University of Padua, Italy found that if your body uses fat as fuel during exercise then it will burn less fat rest of the day.
They have suggested that over a long period, exercising after breakfast would be more effective than fasting training to lose weight through the increased metabolism and reduced RER in the hours after training session. (5)
Another research by Brad Schoenfeld (The hypertrophy Specialist) found no significant difference in fat loss between both group (fasted and fed). (6)
A team of researchers has found the effect of Interval training between two groups (fasted and fed) but didn’t find significant difference in body composition. (7)
If you are thinking to do fasted cardio to achieve greater fat loss, then you should’t do it.
But if you like to train without eating anything then go with it without worrying about muscle loss.
A number of studies has shown no change in fat free mass whether exercise has been performed either in fed state or in fasted state. (8)