Fasted Cardio

I know fasted cardio has its benefits, but is that much better then doing cardio with food in the stomach.

Replies

  • cwolfman13
    cwolfman13 Posts: 40,859 Member
    The primary benefit to doing fasted cardio is from a fitness standpoint, not a diet or weight loss standpoint. The fitness benefit of doing fasted cardio is teaching the body how to more efficiently use fat for fuel during an endurance event to help prevent bonking...outside of that, there is no real benefit other than preference.

    Fasted cardio does not result in more net fat loss for a particular period...it just means you're using more fat for fuel for that particular activity...your body constantly cycles through fat oxidation/storage. Your fat loss will be a result of your deficit...fasted cardio doesn't result in greater fat loss...if you have a 500 calorie deficit, you're going to lose about 1 Lb per week on average over time regardless of whether you're exercising fasted or with food.
  • Cherimoose
    Cherimoose Posts: 5,210 Member
    palmerc19 wrote: »
    I know fasted cardio has its benefits, but is that much better then doing cardio with food in the stomach.

    No.
  • kimothy38
    kimothy38 Posts: 840 Member
    Personally I feel weak doing any sort of training after a fasting day or first thing in the morning. At a minimum I have a BCAA drink for some fuel - makes a big difference for me.
  • sijomial
    sijomial Posts: 19,606 Member
    In a nutshell doing (some) fasted cardio made me much better at doing fasted cardio in my personal experience.
    It took quite a few weeks to get my performance fasted to match performance when fed but it never exceeded it.

    It was a slight benefit to me as I do long distance cycle rides so it gave me more flexibility in fuelling my rides and gave me more flexibility in scheduling my training without having to worry so much about meal timing.

    Doesn't make any difference to weight loss though.
  • NorthCascades
    NorthCascades Posts: 10,895 Member
    palmerc19 wrote: »
    I know fasted cardio has its benefits, but is that much better then doing cardio with food in the stomach.

    For me, the benefit is it's easier to ride hard without food in the stomach.

    Well, the other benefit is I can get on the bike sooner if I don't have to eat first.
  • GiddyupTim
    GiddyupTim Posts: 2,819 Member
    I just watched a short video where they asked professional tri-athletes what they did for breakfast on the day of races. The answers were all over the place. Some had eggs. Some had carbs. Some ate nothing at all -- these said that their glycogen stores were made the days before, so the day of did not matter that much. (Those that did not eat did say, however, that they took Gu and snacks early and often in their races.)
    I'm guessing this all means it is personal preference.
    I have heard that fasted cardio teaches your body to utilize its fat stores more efficiently, as was mentioned above. But I am going to guess that is not firm science.
    I go for six miles runs before eating pretty often. I cannot honestly say I notice much difference.
  • rybo
    rybo Posts: 5,430 Member
    I've heard lots of arguments for and against fasted cardio. I like it because it's just easier not to eat before morning workouts. I have followed the premise for it to teach your body to use fat for fuel during endurance events... but I have read a few more things that indicate there is a lot more that goes into that than just exercising fasted, and that just exercising in a fasted state may not improve that ability, without other factors like your current condition, intensity and whether your body is already able to switch back and forth from fat to glycogen easily. All that said, I still like to do many runs and training hikes fasted and not take fuel at least a few hours in.
  • mmapags
    mmapags Posts: 8,946 Member
    palmerc19 wrote: »
    I know fasted cardio has its benefits, but is that much better then doing cardio with food in the stomach.

    Is it better for what?
  • DX2JX2
    DX2JX2 Posts: 1,921 Member
    Nope. No real physical benefit vs. unfasted cardio but you could make an argument that not eating beforehand removes any chance that something will sit wrong in your stomach and keep you from performing your best.

    I'm guessing that most people who do fasted cardio (me included) do so simply because we workout first thing in the morning and don't want to bother eating beforehand. It's just easier from a pure logistics standpoint.
  • BrianSharpe
    BrianSharpe Posts: 9,148 Member
    It really comes down to personal preference.

    I usually run early in the morning and having food in my stomach makes me feel uncomfortable and I have enough glycogen store to see me through about 90 minutes of moderate exercise. On a race day I'll eat something light at least a couple of hours before the gun goes off.

    As to benefits I think Azdak covered it perfectly. The whole fat burning thing is (intentionally?) misrepresented by many in the fitness industry and is really only of interest to endurance athletes.

  • NorthCascades
    NorthCascades Posts: 10,895 Member
    I've never really understood the fat burning thing. You get that from aerobic exercise regardless.
  • stanmann571
    stanmann571 Posts: 5,736 Member
    Benefits
    1. Roll out of bed... Boom Go
    2. It appears for many to have some degree of appetite suppression when done immediately after sleeping.

    The rest. Meh!
  • Azdak
    Azdak Posts: 8,281 Member
    I've never really understood the fat burning thing. You get that from aerobic exercise regardless.

    All systems can be specifically trained. The idea of training ones system to improve fat oxidation is to spare glycogen during extended exercise. The greater the glycogen reserves, the longer one will be able to perform at higher intensity levels.

    You can’t just substitute one energy system for another. There is a limit to how quickly one can produce energy via beta oxidation (fat burning). We were taught that if one had to rely mostly on fat as fuel (eg after a “bonk”), one could only perform at 60% of VO2 max or lower.

    So saving your glycogen reserves can be a positive thing.
  • Azdak
    Azdak Posts: 8,281 Member
    DX2JX2 wrote: »
    Nope. No real physical benefit vs. unfasted cardio but you could make an argument that not eating beforehand removes any chance that something will sit wrong in your stomach and keep you from performing your best.

    I'm guessing that most people who do fasted cardio (me included) do so simply because we workout first thing in the morning and don't want to bother eating beforehand. It's just easier from a pure logistics standpoint.

    Not having enough glycogen available can also keep you from performing your best.

    Most people aren’t going to notice a difference because they don’t work out long enough or hard enough to exhaust their reserves.
  • cwolfman13
    cwolfman13 Posts: 40,859 Member
    GiddyupTim wrote: »
    I just watched a short video where they asked professional tri-athletes what they did for breakfast on the day of races. The answers were all over the place. Some had eggs. Some had carbs. Some ate nothing at all -- these said that their glycogen stores were made the days before, so the day of did not matter that much. (Those that did not eat did say, however, that they took Gu and snacks early and often in their races.)
    I'm guessing this all means it is personal preference.
    I have heard that fasted cardio teaches your body to utilize its fat stores more efficiently, as was mentioned above. But I am going to guess that is not firm science.
    I go for six miles runs before eating pretty often. I cannot honestly say I notice much difference.

    It is good science, it's just misused in regards to losing weight. I don't know any endurance athletes who don't do some of their training fasted (not all of their training)...but that doesn't really have anything to do with a pre-race meal. Most of the endurance athletes I know either eat very small or nothing on race day because you don't want all that stuff sloshing around in your gut. And yes, endurance athletes carb load days in advance, not day of or the night before.
  • sijomial
    sijomial Posts: 19,606 Member
    Azdak wrote: »
    DX2JX2 wrote: »
    Nope. No real physical benefit vs. unfasted cardio but you could make an argument that not eating beforehand removes any chance that something will sit wrong in your stomach and keep you from performing your best.

    I'm guessing that most people who do fasted cardio (me included) do so simply because we workout first thing in the morning and don't want to bother eating beforehand. It's just easier from a pure logistics standpoint.

    Not having enough glycogen available can also keep you from performing your best.

    Most people aren’t going to notice a difference because they don’t work out long enough or hard enough to exhaust their reserves.

    Bold is a very good point - for most it's an irrelevance and I wonder why there's so much agonising over it.
    Perhaps people don't realise quite how much readily available energy reserves they already have onboard?

    I never used to see anyone drinking anything but water in gyms but now the fashion is growing for pre-workout/intra-workout/post-workout supplementation even for some very ordinary and short duration exercise routines.

    For endurance athletes then fuelling becomes a big issue - either to just complete an event but also for performance in an event. I do cycling events up to 9 hours long so I have to think carefully about fuelling but if you are just doing a "standard" one hour workout then just do it (thanks Nike) in the way that fits your schedule and preference.