best times for cardio

Discussion in 'Diet & Nutrition' started by jwbond, May 31, 2005.

  1. jwbond

    jwbond New Member

    I just got back from a trip to the sunny FL beaches and realized I need to lose a bit more fat.

    I know the best time to do cardio to lose fat is upon waking prior to eating, but I am not a morning person. I have read of people doing 20-30 mins after lifting.

    What are the best times to do cardio to maximize fat loss?
     
  2. kyleman1

    kyleman1 New Member

    The best time to do cardio to maximize fat loss would be to do it when body fat is the primary fuel source.

    If you just ate, then the food you just ate will most likely be metabolized to power your exercise. And if you just ate carbohydrates, then the insulin from that meal will lock down fat cells and throw away the key, making it hard to use energy from fat cells. Itll take a lot more glucagon from exercising to overcome that obstacle.

    If you're glycogen depots (muscular and hepatic) are filled up, you'll most likely use these to fuel your exercise.

    This isn't to say you won't use body fat if you are exercising during these 2 times, but the necessity for using body fat is decreased.

    So the best time? Low glycogen, no food. This is like you said, right when you wake up. Why don't you take some time to actually "wake up" first. Maybe take like an hour or 2 and clear your head, and become more awake, and then do the cardio.

    And if you're trying to lose weight, keep insulin secretions under control.
    -Kyle
     
  3. It has a lot to do with intensity also. Steady State at around 60% Max VO2 has shown to mobilize more fat stores during cardio, even in the face of a non fasted state.
     
  4. jwbond

    jwbond New Member

    steady state? I thought HIIT was best?
     
  5. accu123

    accu123 New Member

    If the goal is to burn fat then steady-state at 60% of your max heart rate is what to do. But because the effort is so low you need to do it for a longer period than a HIIT workout. Some say as much as 85% of calories burned slow and steady are fat, whereas HIT is much more carbs than fat. Some say HIIT increase the metabolism for hours afterwards but others say not all that much. So I’d suggest slow down and go longer 3 times a week, for up to an hour, and do a HIIT session 1-2 times a week.
     
  6. Elle

    Elle New Member

    Most People will say first thing in the morning on an empty stomach, reason being is because your body is short on glycogen supply and will take only fat for fuel for the workout. The point of doing cardio is to alter your internal hormonal environment increasing your metabolism, not burning fat during the workout. There are several important reasons why you should not do cardio first thing in the morning. One, you are more prone to injury, you just woke up from a 6+ hours of sleeping, your body needs warming up before doing intense exercise. Two, your intensity will be decreased, which is extremely important for a good hormonal excreting cardio workout. Three, when you wake up in the morning the hormone cortisol is raised which is the "main" catobolic hormone, which goes away after eating breakfast. Breakfast jumpstarts your metabolism for the day, skipping breakfast and doing cardio instead raises catobolic hormones even more and slows your metabolism, which is a good formula for losing muscle and gaining fat.
    Once you get below 10% bodyfat, morning cardio *might* make a difference. Mainly because it becomes so much more difficult to mobilize/oxidize fatty acids the leaner you get.

    If using fat for fuel (the premise upon which morning cardio is based) was really that important for fat loss, than interval training (which relies solely on glucose/glycogen for energy) wouldn't cause fat loss which it obviously does.

    For the average person, in a more average bodyfat range, I doubt it makes any difference at all: the best time to do cardio is when you will do it consistently.
     
  7. Dood

    Dood New Member

    A couple points I disagree with:
    1. Just because you do cardio before breakfast doesn't mean you have to skip breakfast.

    2. I don't consider steady state at 60% of max to be "intense exercise" which you need to warm up to. In fact I find it to be a good warm up in itself, and you can always start out a little slower for the first few minutes. You can even start out by walking [​IMG]
     
  8. A couple points I see some confusion on,

    1.The point of doing cardio is to alter your internal hormonal environment increasing your metabolism, not burning fat during the workout.

    Abeit any exercise changes hormones, it also has to use some fuel to feed the exercise, substrate usage has been looked at quite extensively during differing modes of exercise and fat is utilized as fuel.

    2. Three, when you wake up in the morning the hormone cortisol is raised which is the "main" catobolic hormone, which goes away after eating breakfast.

    It doesn't go away, it's always there just not above basal setpoint. Also there is little correlation to fed or fasted state, Cortisol will increase in either.
     

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