Calorie restriction vs. cardio for fat loss

[lonestar777]

I came across something on Reddit that made me think of this, and I don't think I've every thought about things in these terms. Let's say you are on a cut, and you know you need to hit 2500 calories per day to lose weight. Is it better for fat loss to restrict the calories to 2500, or would it be better to take in 3000 calories and then do 500 calories worth of cardio? Assume you are doing intense resistance training in both scenarios. The hypothesis would be that you could use the cardio to setup your metabolism for fat burning and more preferentially target fat loss than just calorie restriction alone. Any thoughts?

[mgil]

There’s some notion of EPOC at play there.

Anecdotally, people have had success with cardio in the morning putting a surge demand on the metabolic system. That being said, there’s an expectation that the energy demands are the same as prior to the weight-loss phase all other times of day. I don’t know if this is reasonable.

I do think inclusion of some form of cardio helps balance out training overall.

[rjharris]

I don't know about which is optimal for fat loss, but Nuckols has suggested that maybe you could train harder and/or with more volume if you include some (but not tons of) aerobic training, since a fair bit of the energy needed for sets exceeding a few reps comes from aerobic respiration. If that's true, inclusion of cardio likely impacts body comp down line both directly from fat loss and indirectly through being able to train a bit more.

[Wilhelm]

I suppose you need to specify (or ensure) that no caloric intake will be added in response to the cardio itself, which people often have a tendency to do.

Also, are you really setting up your metabolism for fat burning if you are supplying it with those 500 calories exogenously?
I don't know, that's a sincere question.

[broseph]

My thoughts:

Eating less is easier and more consistent than exercising more.

Caloric expenditure from exercise is highly variable, and likely overestimated.

Big cardio sessions added to my baseline-ish programming have a huge effect on my appetite, I believe disproportionate to the calories burned (disproportionate in the bad direction).

Easy/medium cardio like hiking or incline walking seem to be easy to keep frequent and consistent, and don’t have the same effect on appetite as running or whatever 500 calorie workout you’re planning.

[lheugh]

I came across something on Reddit that made me think of this, and I don't think I've every thought about things in these terms. Let's say you are on a cut, and you know you need to hit 2500 calories per day to lose weight. Is it better for fat loss to restrict the calories to 2500, or would it be better to take in 3000 calories and then do 500 calories worth of cardio? Assume you are doing intense resistance training in both scenarios. The hypothesis would be that you could use the cardio to setup your metabolism for fat burning and more preferentially target fat loss than just calorie restriction alone. Any thoughts?

Based on your selected criteria it would likely not be ideal to attempt to achieve that 500kcal deficit solely off of cardio. If we were to go by the premise that one burns roughly .2kcal (RPE 2-4), .45kcal (RPE 5-7), .7kcal (RPE 8-10) per pound of body weight every 10 minutes or so, it would take quite a time investment or an effort investment to go down that road. This is of course, assuming these are immutable numbers which of course they are not because different modalities provide varying levels of stress. The middle number there refers to actual endurance training as well (.45kcal), which is at the threshold of causing an interference with your resistance training criteria. At the very least, resistance training will be impeded to some degree. Glycogen depletion from higher effort cardio work is a concern, as well as molecular signalling. Resistance training is the single most important factor in muscle maintenance in a caloric restriction (which as a metabolically active tissue you'd want to preserve as much as possible to burn calories) and incorporating too much relatively intensive cardio will take away from productive resistance training. Lighter cardio modalities do not reach this threshold and thus do not interfere with resistance training adaptations, but the cost of this is they do not burn many calories that couldn't just be removed from the diet. That said, as @mgil noted, there are many benefits to incorporating cardio that no other form of exercise can match.

[lonestar777]

Interesting responses - thanks everyone! This is really just more of a thought experience. I probably should have chosen a different number than 500 calories, because I know it's definitely hard to burn that without also impacting the resistance training. I was also assuming a perfect theoretical model, not taking into account the point that @broseph makes about cardio increasing appetite.

As far as the interference, I was thinking more like do a LISS-type session in the morning, potentially fasted. Then doing the resistance training later in the day. Not all in one session.

So my takeaway here is that it's good to do maybe some light cardio, don't let it interfere with resistance training, and rely mostly on eating less to cut the fat. I didn't magically discover that _one weird trick that your doctor's don't want you to know about_.

[TimK]

Also, let's say you actually burn 500 calories doing cardio. If you had just sat on your ass instead over the same time period, you would still have burned 200 calories just being alive, so if you really want a 500 calorie deficit you need to do 700 calories worth of cardio (made up numbers to illustrate the point). This just compounds the difficulty imbalance between cardio deficits and nutritional deficits.

On top of that, you might be tired from all that cardio so you unconsciously move less throughout the rest of the day and burn less calories over that time period, reducing the deficit even further (reduction in NEAT - Non Exercise Activity Thermogenesis). One way people try to combat this is by tracking step counts and trying to keep them at some arbitrary high number throughout the diet.

[GlasgowJock]

On top of that, you might be tired from all that cardio so you unconsciously move less throughout the rest of the day and burn less calories over that time period, reducing the deficit even further (reduction in NEAT - Non Exercise Activity Thermogenesis). One way people try to combat this is by tracking step counts and trying to keep them at some arbitrary high number throughout the diet.

This was one of my first thoughts concerning CICO for fat loss. I'd look to increase my NEAT as a means of consistent additional calorie expenditure and throw in some periodic LISS/ HIIT cardio generally for the aerobic benefits.

I'm not a fan of 'fasted cardio' or 'intermittent dieting' for those wishing to maintain muscle on a cut/ people focusing on resistance training as it's less windows for consistent protein intake, which we're trying to keep *high* and *frequent* while cutting. Rather, just track overall caloric intake throughout the day/ week. However *hand wavey caveats ftw*, if these are tools you find useful for longer term adherence towards the bigger picture then that's key.

[platypus]

I have tried doing moderate cardio (3-5 hours a week) and not doing it in two week increments while dieting. Measuring my waist daily and averaging the numbers weekly, I did not find any appreciable difference in fat loss during the cardio and non-cardio weeks.

For me cardio helps with mood, and with sleeping well on nights when I didn't lift, but it doesn't seem to do much for fat loss.

[lonestar777]

I have tried doing moderate cardio (3-5 hours a week) and not doing it in two week increments while dieting. Measuring my waist daily and averaging the numbers weekly, I did not find any appreciable difference in fat loss during the cardio and non-cardio weeks.

For me cardio helps with mood, and with sleeping well on nights when I didn't lift, but it doesn't seem to do much for fat loss.

Nice, that's an awesome data point!

[Hardartery]

I have tried doing moderate cardio (3-5 hours a week) and not doing it in two week increments while dieting. Measuring my waist daily and averaging the numbers weekly, I did not find any appreciable difference in fat loss during the cardio and non-cardio weeks.

For me cardio helps with mood, and with sleeping well on nights when I didn't lift, but it doesn't seem to do much for fat loss.

My personal experience is also that I can make no positive link between cardio and weight loss. Yesterday was 60 minutes of cardio, no weights, definite caloric deficit, full keto. I am 1lb heavier this morning than yesterday. In my only real previous diet, the cardio made no appreciable difference that I could point to. It was all the diet. I got performance benefits in competition for having better cardio conditioning (My Medley performance was massively better), but cardio every day for 45 mins (Interval on the treadmill that time) didn't budge the scale an ounce. And that was on a diet, but less strict than the one I changed to that dropped the weight.

[Philbert]

My experience with larger amounts of cardio is that it significantly depresses resting energy expenditure. On days when I do longer runs I am cold for hours afterward, and also ravenously hungry. One caveat is that if the necessary caloric restriction makes it difficult to get adequate quantities of other nutrients from food at current activity levels an activity increase to make the diet parameters a little more flexible may be in order. Another is that adding cardio to a stable habitual diet may be easier for some than cutting 100-200 calories from what they always eat.

[Brackish]

I'm sure you could cardio your way into a caloric deficit if you really, really wanted to, but it's a hell of a lot easier to just put less stuff in your mouth.

[mgil]

Also, are you really setting up your metabolism for fat burning if you are supplying it with those 500 calories exogenously?
I don't know, that's a sincere question.

Coming back to this...

I do know that doing something that isn’t a huge strain in the morning (walking, stretching, light mobility work, etc.) will make me run “hot” (as in perspiring) for a couple of hours afterwards. That’s usually coupled with coffee intake. But if I remove the activity, the coffee doesn’t seem to result in the “hot phase” by itself.

I think there is some EPOC merit to the old bodybuilding deal of black coffee and an early morning walk while cutting. The caffeine certainly helps both spin up the metabolism and suppress the appetite. The net effect seems to be a bump in the metabolism from the effort and caffeine, with little to no net increase in appetite likely due to the efficacy of the caffeine and possibly the timing and intensity of the cardio or similar exercise. Further, for those that are caffeine sensitive (I am), this doesn’t impact sleep quality.

[JohnHelton]

During my last cut, I added incline treadmill walking to the mix without adjusting my calories. At first I was doing about 40 minutes per day, and it significantly increased my rate of loss. I eventually dialed that back to 20 minutes, as that was more manageable and my rate of loss was greater than I wanted. At a 3.5%-5% incline and 3 mph, I didn’t find that it affected my appetite nor my lifts.

[Hardartery]

In my limited experience, once I got the ball rolling it slowly picked up speed and then carried on of it's own volition for a while, with or without continued cardio. ATM I'm fighting with the slow speed of progress, but I know once I get to the goal it will have it's own inertia.

[Allentown]

Jordan F had a post about this recently too. Our bodies adapt pretty quickly to cardio for calorie burning, apparently, so supposedly it's better to continue weight training while getting at least the recommended amount of physical activity, but adding in a bunch of cardio likely isn't going to work for weight loss, outside of water weight I guess.

[Boa]

Jordan F had a post about this recently too.

It's caused a metric shit-ton of controversy too...

Our bodies adapt pretty quickly to cardio for calorie burning, apparently, so supposedly it's better to continue weight training while getting at least the recommended amount of physical activity, but adding in a bunch of cardio likely isn't going to work for weight loss, outside of water weight I guess.

I think we need to be more "nuanced" (pun/reference intended) about this. People definitely adapt to ADLs and high amounts of physical activity in the medium to longer term. If they didn't, then manual laborers and sportspeople wouldn't become overweight. So at some point, a person's caloric needs to carry out the same high levels of activity reduce because one becomes more efficient at doing things. I think we all get that.

But I don't think it's as simple as "cardio doesn't increase your energy expenditure once you adapt to it" as a lot of people are taking from that post. Any physical activity above being completely comatose sedentary (the figure RMR is based on) increases one's energy expenditure.

By how much? That depends, but let's say that introducing something like cardio where there was none before results in a not-too-trivial increase to expenditure for a period. Let's say somebody doing 30 min a day of moderate cardio increases their TDEE by +20%, as that becomes more "normal" that figure will possibly drop by half and maybe more (depending on how conditioned somebody is) - assuming the activity remains unchanged. This is where modifying stimuli and progressive overload also comes into play. If that 30 min becomes 60 min, then energy expenditure will increase for a time. If that 30 min moderate cardio becomes highly challenging cardio, then the energy expenditure will increase for a time too.

It's just really fucking hard where cardio is concerned because most of all people (in weight training communities) lift first and foremost. If we look at cardio as being an effective tool for increasing expenditure and weight loss, eventually we'd have to do a lot more of it which means possibly doing less lifting or even abandoning it in favour of cardio.

So I can see what he's getting at, in that it's easier and more efficient to modify these variables that keep an higher energy expenditure on weight training vs cardio. I remember in the past he's mentioned stuff "transient changes in activity don't tend to affect outcomes in expenditure" - which has indeed been found to be the case in short term trials where they've taken people on an exercise program, abruptly stopped it and measured their energy expenditure and it showed minimal change in the short term.

I guess cardio can be a tool in the short term (eg if you're a physique athlete and you need to up the ante for a short period leading into comp), I think if people are inactive save for going to the gym to lift, then that's where anything additional such as walking or increasing physical activity becomes cardio (which will also increase one's TDEE upward a bit for a while).

In short, the increased energy requirements (and thus energy expenditure) broadly comes from lifting and doing cardio at the rate needed to increase it further for more than short periods of time is hard work, and will continually get harder.

[Allentown]

Assuming someone is measuring and tracking their intake, then, it's better for fat loss to just cut out some calories than it is to add in a bunch of cardio, assuming the individual is already getting at least the recommended amount.
"Eyeballing" calories and adding in cardio, though, is either not going to work or work less well than actual calorie restriction, both in my experience and in what I take from Jordan and people like Layne Norton.

Basically, just cut calories, since everyone should be getting regular activity anyways.