We hear it all the time: If you want to lose weight then start running, swimming, jogging, biking, etc. However, we then see many people who have been jogging for over a year or more and really don’t look much different than they did before. Although, then there are those few who come out looking radically different than they did a year ago (whether they keep the weight off or not is a different story).
So what’s the story? Is cardio really effective for fat loss?
The short answer: It depends.
The long answer:
In order to lose weight, you must burn, through metabolism and movement, more calories than you consumed at the end of each day. There is no escaping this rule; it is a fundamental law of thermodynamics: energy cannot be created or destroyed, only transferred. Any weight loss system that tells you otherwise and still works is somehow “tricking” you into eating less calories or exercising more.
Now that we got that out of the way, it should be obvious what cardio depends on in order to be effective: diet.
For the most part, cardio just acts as a way to increase the calories burned that day. So, if your metabolism burns 2500 calories everyday and then you run for a half-hour one day burning 500 calories, then your total calorie burn for that day was 3000 calories. It’s really as simple as that.
If the real-world actually acted like the above example, then cardio would always be effective for fat loss. The problem is that many people don’t keep their diet the same when they are doing cardio.
Many people see cardio as a way to “justify” eating more that day because they burned off a lot of calories running, and so they “deserve” that large cookie. The problem with this is that people almost always vastly overestimate the amount of calories they burned while doing cardio and significantly underestimate how many calories are in whatever they are eating. Furthermore, cardio increases hunger for most people, much of the time disproportionately to the amount of calories that were burned from the cardio.
However, if, for example, you burned 500 cals doing cardio and then ate exactly 500 cals more that day, you would come out with a calorie balance, but the cardio could still have some calorie partitioning effects. This means that more of the calories that you ate would go toward muscle-building stuff and more of the calories that you burned would go towards fat-loss stuff. This minor change in body composition is slight, though. So don’t expect to see any radical changes from using only this method.
Also, just so you know, weight lifting has a much, much larger calorie partitioning effect.
Another good side effect of cardio is that it can help with “stubborn fat”, especially in girls. Stubborn fat is hips and thighs for girls and abs and lower back for guys, for the most part. This is always the last fat to go, but the process can be sped up using some specific types of cardio, but that is for a later article.
(Note: I did not say you can spot reduce fat, ’cause you can’t.)
If you want to know if cardio will help you personally in your quest to lose some fat, you have to ask yourself this question: Will doing cardio help or hinder you sticking to your diet?
For some people, doing cardio will fuel their motivation and make them feel like “Well I don’t want to go through all that running and then get nothing out of it”. For others, they use cardio to justify having an all-you-can-eat day. It really just depends on the person. Also, if cardio really spikes your hunger, then you might want to try either a different form of cardio (HIIT => steady-state || steady-state => HIIT) as some people have different reactions to different intensity levels, or you can just not do it at all and put all your focus on weight training instead.
Lastly, from a physiological standpoint, to decide if the calorie partitioning effect of cardio is necessary for you, you need to look at your starting body-fat percentage. If you have a lot of body-fat, then you won’t really see much improvement from cardio because most of the calories from the calorie deficit due to the diet will come from fat anyway, so jogging 500 cals off will have about the same effect as not eating that muffin, and not eating the muffin takes a lot less time.
If you are starting out with a fairly low body-fat level, then you may see some improvement from incorporating some cardio to increase the calorie deficit. Just make sure that if you add a TON of cardio that you are not going into too much of a calorie deficit, because then your body will be more inclined to take the energy it needs from your lean muscle mass instead of your fat cells. However, if you are keeping a nice 200-500 cal deficit or whatever, then having some of that come from cardio will probably mean more of the weight you lose will be fat, not muscle.
Lastly, studies have shown that it doesn’t really matter whether you want to do slow steady-state cardio or HIIT interval-style cardio. As long as you do the same amount of work, you will burn about the same amount of calories. With steady-state (or LISS), most of the fat will be burned while performing the exercise whereas with something like HIIT, much of the fat will be burned for hours after the exercise. In the end, it just comes down to which type your prefer personally, and which you will be more likely to stick with. If that happens to be dancing in front of your television, so be it.
So now you can see that just by performing cardio, your waistline won’t just magically decrease, especially if your diet isn’t up to par. Most of whether or not you want to do cardio comes to personal preference. Do you want to run a bit so that you can eat a little (remember.. a little) more, or do you just not want to eat as much food. If you need to lose A TON of weight, you are much better off dieting the weight off and lifting heavy weights to keep the muscle you have than try to run the weight off.
If you have any comments, questions, or concerns, please leave a comment below. I want to hear from you!
2 Comments
dear Sir,
Just a short comment on the above; if you have a lot of weight to loose in fat form you need to create a larger calorific deficit in order to burn off more pounds. Because you have such a large store of fat your body will tend to use this rather than your hard earned muscle at the source therefore doing lots of cardio and some wights is a superior strategy to just weights alone which has a comparable low calorie cost and hence is unlikely to create the deficit which as you point out is key for the first law of thermodynamics (nicely put by the way). The above is supported from personal experience; weight alone sculped new muscle and actually addeed weight (muscle and fat) due to very much increased satiety that weight training induces via hormones. If you have a low amount of fat to loose you are problably best sticking to weights alone as the deficit would probably be enough to see the loss. Your argument regarding not seeing the loss as a reason for avoiding cardio if you are big is flawed; you will never see the loss when you are big but it is going on!!!
keep the good point flowing bw
“increased satiety that weight training induces via hormones.” – Do you have a source for that? Not trying to say you’re wrong, I just want to know where you got that from.
It doesn’t matter if you have a lot of fat to lose or a little – A deficit is a deficit. If you want to eat 2000 cals everyday (because your maintenance is 3000, for example), you can achieve that by only eating 2000 calories, or by eating 2500 cals and doing cardio to burn off 500 cals. Many people counter this by saying that that cardio will make more of the deficit come from fat instead of muscle. However, recent studies have not been supporting this theory http://www.ncbi.nlm.nih.gov/pubmed/19833807
Also, you don’t always need a very large deficit unless you have some competition, photoshoot, etc. coming up soon. Otherwise, most of the time you are better off losing fat in a longer time period in order to keep your muscle mass.
The only exception I would have for any of this is for very light female athletes. In order to create a reasonable deficit, they would need to sacrifice a large percentage of their daily calories, which might not allow them to get all the micro-nutrients they need from food. So in that case, cardio might be a good idea to create some of that deficit, allowing them to heat nutritional foods.