Does fasted cardio really burn more fat or should I have a coffee and some BCAAs before, or even a pre-workout meal as standard? We put the question to a panel of experts in the industry and here’s what they said followed by our own resident WBFF fitness pro and digital editor, Altu Kop’s summary on this highly debated topic.
Does fasted cardio burn more fat?
Jordan Wheeler
Yes, fasted cardio will burn more fat than if you were to do the same cardio later in the day. Both coffee and BCAAs have a very minute amount of calories, so they shouldn’t affect your fat burning. Personally, when I do fasted cardio, I sip on some black coffee.
Nick Cheadle
Research suggests this comes down to personal preference, as net calorie expenditure should be the same. However, properly feeding yourself before will more than likely help you get more out of your workouts to burn calories.
Ricky Jasper
If your goal were to maintain muscle or build mass then having coffee and BCAAs before would be best in order to provide the most broken down form of protein and a bit of extra energy. If you are not worried about losing a bit of mass, then fasted cardio will burn fat. Stay away from HIIT fasted.
Reuben Brooks
I say do fasted cardio and have a coffee with BCAAs. Doing the fasted cardio promotes lipolysis (the amount of fat broken down) but it doesn’t increase fat oxidation (the amount of fat burned).
Brian Decosta
I’ve never noticed a difference. At the end of the day, the principle of calories in versus calories out still holds true. If you create a caloric deficit you will see fat loss if
the deficit is kept over a period of time.
Altug Kop – TRAIN Digital Editor
I think Nick Cheadle hit the nail right on the head here. There is zero research to indicate that fasted cardio is superior to non-fasted cardio and there is some research to suggest that being fed before a session will burn more calories than fasted, due to your increased performance capability. Nick is right on both counts.
There is a lot of misinterpretation because research does show that fasted cardio burns more fat calories during the session. However, what we’re interested in is how much fat is burned over the entire 24 hour period than in a short, isolated session and overall fat burned by the end of the day is the same for fasted or fed cardio (which Reuben correctly alluded to.)
Your main goal when burning fat shouldn’t be to burn as much fat as possible, ironically. It should be first and foremost to retain as much hard-earned muscle tissue. That is where there is some uncertainty about whether fasted cardio eats into lean tissue.
Personally, for me, it’s not worth taking the chance. It takes infinitely longer to build muscle than it does to burn fat so why would I risk muscle tissue for a marginal fat loss benefit that research doesn’t even show is there? Makes zero sense to me.
However, if it’s the only time you can get your cardio in, I also don’t see much evidence against fasted cardio either so go for it. Most of the experts suggested bcaa’s and caffeine before doing so, which is a good precaution.
This topic was also covered in a column for the print version of TRAIN magazine. Here’s what was said:
Many people do moderate intensity cardio in the morning (with ca ffeine) using cardio equipment guidance into fat-burning zones.
“Experts” suggest that during sleep your body transitions into early fasting, and fat breakdown and oxidation are maximized. So by doing fat-burning cardio in the morning it will extend and amplify the fat burning processes and increase the total fat burned during exercise over the day and weeks.
This is commonly referred to as “Fasted Cardio” and is applied by performance and physique athletes as well as soccer moms. However, I’ve been on a warpath on this topic for three years and guided several studies to discover if we are doing it wrong!
Firstly, it’s a matter of priority as muscle protein breakdown (MPB) will remain greater than muscle protein synthesis (MPS) for a longer period, creating a morning muscle protein hole that you must overcome before becoming positive or breaking even for the day. Also, fasted cardio is not based on research but hopeful reasoning so it lives in the realm of broscience.
The current research on fasted cardio burning more fat
1. No more fat is burned if you do cardio fasted compared to doing it after eating protein.
A study by Brad Schoenfeld and Alan Aragon in the Journal of the International Society of Sports Nutrition showed no significant differences in fat mass lost between both fasted and fed cardio groups.
2. Eating protein can hike up your metabolism and enhance fat burning during and after exercise.
Clearly the smart play is protein before bed and upon waking to support 24-hour MPS and net positive muscle protein balance – a “break-even muscle scenario”. Furthermore, I am beginning to wonder if protein makes sense before AND after exercise to reap metabolic benefits along with MPS. Certainly protein every three to five hours (daily protein pacing) would support this notion.
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