Fasted Cardio For Fat Loss
EC believes that fasted cardio is a big no-no, as it may limit your performance and therefore calories burnt. Time for a different opinion!
Fasted Cardio For Fat Loss
I was asked by the head of this excellent website to give my opinion on fasted cardio, defined as doing cardio long enough after eating that we are in a fat-burning state having for the most part used up much of our glycogen reserves.
I have been doing fasted cardio for many years. For me that means first thing in the morning before I break-the-fast with a breakfast. The cardio I do is running, five to ten miles, outside in nature. It can be described as long, slow, distance. My pace is in the vicinity of seven to eight minutes a mile, but I really don’t worry about it. I just run as fast as is comfortable for me. After many years of running, I imagine as most runners do, I have a built-in time-keeper.
I never worried about intensity. I started running before they named HIIT (High Intensity Interval Training), although I would do speed work or intervals if I had a race in the near future.
Questionable, But Works!
The result of this questionable activity is that I was quite awake and alert when I got to work in my job as a surgeon. I have maintained a low body fat percentage (<10%), low normal BMI, and 29 inch waist for many years with this lifestyle.
It’s not that I planned on this lifestyle, but the crunch of time and unpredictable hours of my profession, never knowing how my day would go, led me to run or go to the gym first thing in the early morning to get it over and done with. What I discovered was that my fat was disappearing.
A recent study from Northumbria University by Dr Emma Stevenson, Javier Gonzalez, and Ben Green, was published online in the British Journal of Nutrition.
The study examined twelve physically active male subjects who ran on a treadmill, either after they had eaten breakfast or in a fasted state having not eaten since the evening before.
The results showed that those who had exercised in a fasted state burned almost 20% more fat compared to those who had consumed breakfast before their workout.
The study concluded that “Our results show that exercise does not increase your appetite, hunger or food consumption later in the day and to get the most out of your session it may be optimal to perform this after an overnight fast.”
Just Do It!
Rather than worrying about whether fasted cardio works or not, here is your chance to be the experiment. Just do it and let us know whether or not it works for you in achieving your personal goals.
Even if one doesn’t want to do fasted cardio, I still would recommend morning cardio for most people.
Dr. J is regular contributor about all topics health and fitness over at CalorieLab. A Florida surgeon and fitness freak with a black belt in karate, he runs 50 miles a week and flies a Cherokee Arrow 200.
Picture courtesy of Waqas Mustafeez.
13 Comments
Funny – I have been doing fasted cardio for years. I always work-out first thing in the morning and never eat prior to my work-out (whether it is running, weights or whatever). It works for me and my needs. I don’t do it as a weight loss tool – just the way I work out best!
This is why I wanted to feature Dr J’s (contrary) point of view on this: having some carbs to burn should make you last longer, but, because we are all individuals, you as a person might still get along better with fasted cardio.
I try to get my cardio in the morning as much as possible, but I can’t imagine doing it without at least a small breakfast. I get no-food nausea pretty easily.
Been doing it for years both when I did less HIIT & intervals & now when I do more. I have never had an issue. I know some need a little something in their stomach or they get feeling sick or faint. For me, I feel better wit h fasted workouts… 🙂 Hi Dr. J – good to see you here!
Kim!
I don’t use it for weight loss either, but it’s a good shredder 🙂
Jenn!
What you are doing seems to have worked very well for you!
Jody!
Thank you! Same with fasted flying for me 🙂
I do this too, although I only go 3 miles! I feel sick if I eat before I exercise first thing in the morning.
I’ve found doing cardio (bicycling) and lifting on an empty stomach does indeed burn the fat….and have also found it does not burn your muscle providing you keep it within an hour or less. The bicycle allows for interval changes and HR intensity. I’m typically between 75% to 85% of my max and in the “zone”. 40 to 50 minutes of this then getting nutrition immediately afterwards has been rewarding. Last 12 week transformation I participated in I went from 25% BF to 11.3% in 12 weeks…….proof is in the pudding!.
This time around, I’m at week 8 of my program (lift, cardio alternated each day for 6 days a week) and am on course to do so again. Fasted cardio works very well for me.
Dave!
Thanks, that’s my experience with fasted cardio also!
Hiya Dr. J! Great article!
I’m seriously considering doing fasted cardio in the morning also. I read in some articles that this is good for fat-burning compared to regular cardio, where you eat something before cardio.
My main goal is to lose belly fat.. I’m pretty okay all around now, except I just have that lower belly fat that I would like to get rid of.
I know there is no spot removal, but since fasted cardio burns ‘fat’ better, then maybe this can really help me.
What do you think? 😀
Try it and let me know how it goes 🙂
Good luck!
Hey! Great interpretation of the study. One thing question I have yet to see answered was what is the optimum time/length of the workout in order to maximize the fat burning benefits. For instance is there a ‘bell curve’ of efficiency where too short will have no effect and too long will start to burn muscle protein??
Thank you!
J asked for my opinion on this, so here goes: I believe you would have to go to some extreme lengths to start burning muscle.
In fasted state, blood glucose will be low and protein and fat will pick up the bill, but there should be enough free flowing amino acids (= protein) in your bloodstream to fuel your activity.
A half hour run, for example, is unlikely to push it.
Yaj!
Perhaps EC can give you more information. The best I can offer you is that working out no more than an hour fasted will probably give you the results you are looking for. There may well be a bell-shaped curve for an affect but it would most likely vary from person to person. You may have to experiment and see how you personally respond to fasted cardio.