Is Cardio Necessary for Fat Loss when Intermittent Fasting?

Three shredded physiques obtained without any cardio ripped body

“Time is your most precious gift because you only have a set amount of it. You can make more money, but you can’t make more time. When you give someone your time, you are giving them a portion of your life that you’ll never get back.”

I don’t have a problem with cardio, just wasted time. For those that enjoy cardio then this is time well spent; everyone has their own preferences, live and let live. Let’s not pretend though that most people aren’t solely doing cardio because they wish to lose fat.

Cardio as a tool for fat loss is over-rated, over-used, and overall a very poor time investment for the IF user. Most people that ask me questions about cardio understand this, however there is confusion as to at what point cardio becomes necessary to get leaner.

Scott, Jeff and Phil pictured above did not use cardio to get into their shredded condition. I told them that they wouldn’t need it to get to a body-fat level they would be satisfied with. I suggest to you that the answer is likely the same. In my opinion the vast majority of people give up on diet manipulation alone as a means of achieving their ideal physique way too early.

At What Point Do You Need Cardio?

Intermittent Fasting (particularly the Leangains type where people skip breakfast) can perhaps enable us to get to leaner than with other diet methods through diet manipulation alone. This is due to the following factors:

  • The increased ease at creating a calorie deficit through an increase in satiety and better hunger control.
  • The increased potential to get to stubborn fat.

This article focuses on the latter point, though I must add that it is hypothetical, with little clinical research to support it at present. This will be enough for most people, however, there is a limit to how far you can take it no matter how skillful you are at manipulating your diet; the reason is stubborn body fat.

What Is Stubborn Body Fat?

Stubborn body fat is physiologically different from other fat in your body and this makes the removal of it difficult. Typically stubborn fat is found in the lower abs, back, and glutes in men; thighs, glutes, and hips in women.

What Makes Stubborn Fat Stubborn?

There is a theoretical limit on how much fat can be oxidized (burned) before the body will fuel itself by breaking down muscle mass. Fatter individuals can afford a greater deficit before this happens than leaner individuals because the body uses fuels in the ratio they are available. – Fat people clearly have their pantry stocked with a lot of butter, a little meat; shredded people with just a little butter, a lot of meat.

For fat loss three things need to happen:

  1. Lipolysis: Fat needs to be broken down into free fatty acids (FFAs) and released from the fat cell into the blood stream.
  2. Transport: The FFAs need to be transported through the blood to somewhere where they can be used for fuel.
  3. Oxidation: Tissues somewhere in the body need to pluck these FFAs from the blood stream and use them for energy.

When getting really lean (assuming a calorie deficit) the body has only muscle or the stubborn fat reserves left to fuel itself on. Due to the physiological differences of stubborn fat, both 1 and 2 are particularly tough to achieve. So though a calorie deficit may be present and the body ready to use the free fatty acids as energy (step 3), if they aren’t in the blood stream around those tissues, they can’t be used, and the body will break down muscle tissue to fuel itself. Clearly, you want to avoid this situation.

How Intermittent Fasting Can Help With Lipolysis

Unfavourable (for physique purposes) alpha/beta receptor ratio differences in the stubborn fat areas of the body are what makes it difficult for lipolysis to take place. To keep it simple, let’s just say that the morning fasting, by increasing catecholamine output and lowering insulin in the blood stream, creates circumstances which help to get around the receptor issues to allow the fat to escape the fat cells.

How Cardio Helps With Transport (by getting more blood flow to the right areas)

Before your eyes glaze over with the science please stand up and drop your pants. Take your right palm and slide it onto your right arse cheek. Is it cold? Relatively colder I bet. That’s because the blood flow to your glutes and other stubborn-fat areas is poorer. This matters because even if you overcome the problems associated releasing the FFAs (fat) into the blood stream if there isn’t sufficient enough blood flow to carry them elsewhere to be burned then they will just be reabsorbed into the fat cell.

  • Cardio can increase blood flow to these areas, which is one reason why you may have heard nutritionist Martin Berkhan recommend fasted walking on non-training days.
  • Yohimbine HCL can increase blood flow to these areas, which is why you may have heard that recommended also, but it would be a waste of money to take it before you get to the stubborn fat stage. (Incidentally it’s banned in many countries, not because of people taking it for stubborn fat loss, but because of idiots mega-dosing with it to boost erections.)

The Risks: IF can make it easier to burn stubborn fat, but increases the risk of muscle loss.

(Note: this is only really relevant when looking to get to exceptionally lean levels of body fat like you see above. – As long as you have your calorie intake and macros set up right.)

It would be remiss of me to not mention this: The leaner we get, the greater the potential for muscle loss with a reduced meal frequency. It’s important to put this in perspective and weigh up the pros and cons.

If you eat a greater meal frequency and spread your meals further across the day instead of skipping breakfast, your risk of muscle mass losses will be minimized, but you add in more complication to your diet. – Meal preparation takes more time, macro counting is incrementally harder, and you likely have to add in cardio sooner to get shredded lean. (i.e. If you skip breakfast you might be able to get to 7% body fat without cardio, but if you eat breakfast you might only be able to get to 9%.)

How much of a risk is it to skip breakfast?

This depends. The greater the calorie deficit and the leaner you are, the greater the risk of muscle loss. But if you take things slow and steady then the risk is small. I’ve coached over 1000 people with the majority of them choosing to skip breakfast and I can’t say I have noticed it causing any significant lean tissue losses. The clients you see in the top picture skipped breakfast, ate twice a day, and did not use any cardio to get into that condition.

However, it’s important to consider that they were recreational trainees without a deadline, not professional or serious amateur competitors looking to get any potential possible edge over the competition. The calorie deficits were moderate, training intensity was kept high, protein intake was kept high, and BCAAs were used in cases where they trained fasted. (My guide to setting this all up here.) In the case of a top-tier bodybuilder, it would be better to go with the more conservative approach and have a higher meal frequency (assuming they had the time and will to do it). Also, if someone is in a rush to get into stage-ready condition and so the deficit they need to have is greater than what would be most conservative for muscle mass retention, a greater meal frequency should be considered.

I’d add further that anyone convinced that they will lose muscle mass by fasting would be best to not fast. – The mind has a powerful effect on the body and this could indirectly cause muscle mass losses via increased stress and poorer training.

What if muscle mass is lost?

Outside of competing, it won’t really matter as you’ll gain it all back again quickly when you move into maintenance calorie circumstances after your cut. This is due to good old myonuclear domain theory. Results - Katsu

Japanese client Katsu winning his class. He also skipped breakfast, ate just two meals a day and didn’t do any cardio.

Summary & Further Reading

Don’t kid yourself about what stubborn body fat is. Too often people at 15% cry about “stubborn body fat” when they are nowhere near that point yet. Due to genetic difference some folks seem to have more stubborn fat than others. If we say that the above three guys are at around 7%, even if you’re on the unlucky end of that genetic difference you should be able to get to 10% before running into issues. This will still be good enough for a good set of abs, at the very least a well-defined 4 pack.

 – Think before you give a portion of your life to a treadmill. –

Lyle McDonald’s book “The Stubborn Fat Solution” gives an excellent insight into what makes stubborn fat stubborn. Martin Berkhan has done a great job of explaining why IF can help with stubborn fat losses in his own article here.

If you’re interested in practical guidelines on how to set up your diet so that you don’t fall foul of any of these mistakes then you can get my complete set-up guide here. (This is the most viewed page on the site.)


Thanks for reading. Questions welcomed in the comments as always. – Andy.

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About the Author

Andy Morgan

Hi, I'm Andy, co-author of 'The Muscle and Strength Pyramid' textbooks and founder of This site is my sincere effort to build the best nutrition and training guides on the internet. Some readers hire me to coach them, which I've been doing full-time, online, for the last seven years. If you're interested in individualized, one-on-one coaching to help you crush your physique goals, let's start the conversation. (You can read more detailed bio here.)


  1. Antonio Martinez Garcia says:

    Hi Andy, I’ve been reading carefuly all your articles during the past 3 weeks, while I was on holidays and preparing all in my mind and agenda to start with IF as soon as I got back home…

    I’m 39 years old male, fit (I would say) but not lean… Just got out of an hypercaloric diet right before the holidays started, as I was getting fat even though my whole training was quite intense…

    Will not extend my topic too much… Just to comment that I decreased my calories intake during the holidays, almost no cardio, just weight lifting and I lost fat in a matter of 2 weeks…

    In my normal life, I do weight lifting 4 times a week, and practice Muay Thai (can be compared with a HIIT easy) 2 times per week and BJJ (not so much cardio, but still a demanding activity) 3 times per week, sometimes 4…
    Trying to rest at least 2 days per week…

    As I do the martial arts usually in the morning and the lifting in the late noon/evening, I was quite sure about the BCAA’s intake for my early trainings after read your articles, but I read somewhere here that you recommend to only intake BCAA in case of weight lift training only…

    So, how do you see to perform this activies (Muay Thai and Brazilian Jiu Jitsu) fasted and then start eating around lunch time? No BCAA’s ?

    Thanks in advance.

    1. Andy Morgan says:

      It’s fine to do your Muay Thai and BJJ training fasted as long as you feel fine doing that. No real need for BCAAs like with the strength training as the risk of muscle breakdown is less.

      1. Antonio Martinez Garcia says:

        Thanks for the quick and precise answer Andy.

  2. […] For more, see the article, ‘When is Cardio a Valid Tool for Fat Loss with Intermittent Fasting?‘. […]

  3. Justin says:

    I enjoy doing HIIT cardio 2 or 3 times a week as well as lifting heavy in a progressive overload style 4 days a week(1 meal before training set up..cardio is done in the AM). My question I need to recover from the HIIT sessions any differently..or BCAAs on those days?

    1. Andy Morgan says:

      Hi Justin, thanks for the question. BCAA supplementation is only necessary with fasted strength training.

  4. Josh says:

    Hey Andy,

    First and foremost I love the site. I’ve read your articles roughly every day for the past two weeks and I’m finding it easier than ever to maintain proper eating and training habits.

    I’m currently in the hiring process to become a fire fighter and I need to keep my cardio up for fire academy once I’m hired. I’m currently doing HIIT spring sessions for 20 min (including a 2 min warm up and cool down light jog) twice a week and a moderate intensity stair climbing session for 20 min once a week. I am also doing a 5×5 training program where I only do compound lifts 3 times a week. I’m roughly 25-30% body fat. I currently have my calorie deficit set up for a 1-1.5 lb of fat loss per week and have two questions:

    1) Should I increase calorie consumption to create a buffer for the cardio? I’m trying to minimize muscle loss due to burning more calories.

    2) Since I have to do cardio would you recommend doing it before or after my resistance training? My goal is to increase strength and muscle mass > cardio.

    Thanks for your help,

    1. Andy Morgan says:

      Hi Josh, thanks for the question. I’ve helped a two people pass their fitness tests specifically to become firefighters.

      1. Yes. This will be factored into your calorie calculation via the activity multiplier. If you didn’t do this, keep with what you have, guess at the calorie expenditure for this, and roughly that amount of carbs into your diet on that day.
      My goal is to increase strength and muscle mass > cardio.
      2. Then do your cardio at a time of day and week that it least impacts the strength training. Preferably separate then rather than doing them back to back, but if you have to then do the cardio after.

      1. Josh says:

        Great! Thanks for the reply, Andy!

  5. Sebastian says:

    Good content as always.

    I’m thinking of doing at least moderate cardio just to increase the calorie intake on a cut, this so that I can increase my carbs intake.

    Otherwise, with all the other parameters considered, the carbs intake will be at levels that are both hard to adhere to and unpleasant. (I know some people think low carbs diets are the greatest thing ever, I’ve just never been able to handle it well)

    Does increasing carbs intake seem like a valid reason to add cardio exercise on rest days?

    1. Andy Morgan says:

      Hi Sebastian, thanks for the question.

      If you wish to maintain your calorie balance, and you are going to do cardio, then you will need to increase calories to account for that. You can do that by increasing carbs, yes.
      If you wish to add cardio instead of making a calorie reduction to create the necessary deficit, so that you can keep progressing while eating a higher carb amount each day, also yes, you can.

  6. Joram Kalsbeek says:

    Hi Andy,

    (I live in Holland and my English is not my best… but I will try)

    I have downloaded you’re diet guideline to setting up my diet. On the first place I’m very thankful for you’re effort in the guideline. Already noticing progress. Only now I see that my skin at my abs area is becoming some lose skin, do you have any suggesting’s for that issue?

    My second question is concerning chapter 4 and then especially page 46 at the top “Despite this you’ll find some fancy ideas out there such as: only eat fats and protein earlier in the day, and only carbs and protein later. – This is not likely to have any nutrient partitioning benefits, and will threaten adherence by making your diet more complicated and restrictive”.

    Question: referring to Carb Backloading, isn’t there a benefit to eat about 30 grams carbs throughout the day and then after exercising the rest of the daily macro’s (carbs) ? I’m curious what’s you’re opinion about this is?

    This come to my third question is: after calculating my daily macro’s with the help of you’re excel sheet.

    [DELETED by Andy as per comment rules]

    On my training days I’m leaning to eat about 30 grams of carbs and then de rest of the Carbs approximately 200 grams after my training. But then I’m really have a full belly and a inflated feeling in my stomach. Do you think it is sensible to eat according this Carb Backloading principles ?

    Sorry for my last question: what’s you opinion about reverse dieting when you have completed you’re goal in cutting en want to go for bulking? First 2 weeks after cutting calculating for maintenance and then bulking or…..?

    Joram Kalsbeek
    The Netherlands

    1. Andy Morgan says:

      Hi Joran, thanks for the questions.
      Only now I see that my skin at my abs area is becoming some lose skin, do you have any suggesting’s for that issue?
      – In all but the most extreme cases it’s just a matter of patience, it will come tight over time.
      …isn’t there a benefit to eat about 30 grams carbs throughout the day and then after exercising the rest of the daily macro’s (carbs)?
      – No. This is an invented proposition from a man trying to sell you an ebook/dream. Have another look at the timing section of the complete guide, I have it covered there.
      Do you think it is sensible to eat according this Carb Backloading principles?
      – No. Stuffing yourself in one meal when you’re already feeling too full and uncomfortable is exactly the opposite of what you need right now. Consider spreading your carb intake out a little more. See the FAQ, section “too full”.
      what’s you opinion about reverse dieting when you have completed you’re goal in cutting en want to go for bulking?
      – Check out my guide to coming back to maintenance here:
      How Do I Find Maintenance Calorie Intake After Dieting?

  7. Leonardo says:

    Hi Andy,

    I’ve been following your guides for a few months and I’m pleased with the results. My only concern actually is that I’m stuck at 10-11% BF for several weeks. I did a diet break but it didn’t seem to work, still stuck.

    I’m on a solid training routine and I have good control of my calories and macros so I believe I’m limited by stress and maybe poor quality sleep (2 children). I’m sleeping an average of 7hrs/day. Is there any simple test that allow me to measure my stress level or even estimate if I’m sleeping enough?



    1. Andy Morgan says:

      Hi Leonardo, thanks for the questions.
      Is there any simple test that allow me to measure my stress level or even estimate if I’m sleeping enough?
      For the former, no. For the latter, can you wake without an alarm clock? Do you feel exceptionally tired in the mornings? If you have to ask then you’re probably not getting enough.

      I’m stuck at 10-11% BF for several weeks.
      This is something of a red flag. – How do you know? Suggests you might not be tracking as I advise. Avoid trying to measure body fat percentage, focus on detailed body measurements and scale weight changes. Guide here.

  8. rusty says:

    Hi bro, really need your advice here..i’m on bulking mode for past 4 months.gain around 10kg so far..was doing 3-day split push/pull programme..doing calorie counting on my own. The prob is my stubborn fat around my belly still there and my stomach getting bloated/bigger while other body parts can c improvement. Is this norm or what? Care to advice?

    Thanks in advance

    1. Andy Morgan says:

      Care to advice?

  9. Peter W says:

    Andy, first thanks for this wealth of information. My question is that I’m confused about how to track my exercise with regard to MyFitnessPal: specifically, do I add the calories burned from my cycling rides or not? I typically burn between 500 calories on a short ride and up to 1500 on longer ones. I’m training for endurance rides.

    First, I found my TDEE. Then I used your calculator and guide. I did factor in about 67 minutes of exercise per day, 6 days a week using your calculator. That’s three days of lifting and 3 days of cycling. So it seems to me that I wouldn’t want to enter any calories burned into MyFitnessPal because they’ve already been accounted for in your calculator. Would that be correct?

    If I should enter those calories burned (from my garmin) then would I need to replace them?

    1. Andy Morgan says:

      Hi Peter, correct. If you then enter in your Garmin data you’ll be counting the calories twice and will overeat. If you wish to use the Garmin data, set the activity multiplier without your cycling.

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