A new article on fasted cardio appearing in the Strength and Conditioning Journal by Brad Schoenfeld, MSc, CSCS
I put the full text below for those who are interested. For those that are lazy to read the whole thing here are the cliffs:
-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.
