I am interested to know which approach is more effective if someone likes to hold his current muscle bulk but only lose fat?

Is it better to keep the previous diet but add more cardio exercises? Or just keep doing the workout as before and reduce the income calorie intake?

Which one is more effective?

PS: I know we can do both. My point is understanding the more effective way.

EDIT: Due to @gustafc 's answer, I want to add a personal experience of someone around 20-25% body fat(that is mostly belly fat) who does intense bodybuilding exercises 3-4 day per week. What I faced in while I restricted my calorie intake(even by keeping high amount of protein intake) was more muscle pain, lateق recovery and having not enough energy to workout as before, by the end I felt I am loosing muscle even more than fat!

َFurthermore, I know from my previous knowledge an average person who wants to gain muscle should increase his/her calorie intake by around 500kcal per day. So it means wen you try to gain more muscle while you do not eat more than before, it means you have cut 500 kcal of your intake. But it seems in reality or body doesn't like to use it's fat to gain this energy and prefers to burn muscle! And this is my big problem and don't know how to switch my body to use it's belly fat not the muscles I gain hardly by intense workout.

For example I do chest + arm workout on Monday, then Shoulder + back on Wednesday, and at the Wednesday my body says: "Oh it seems we are on low calorie budget, but we have a lot of chest/arm muscles we stored and don't need them in our daily life at least up to the next week, so let's burn them and gain more energy fo our workout!".

This is the problem I have with my body and it seems it doesn't like to burn it's belly fat until it has some extra stored muscl1 to burn.

  • 2
    "More effective" is subjective. Each person will react differently to diet and cardio. You should keep notes and find out what works for you individually.
    – rrirower
    Commented Apr 1, 2022 at 14:58

2 Answers 2


There's been a lot of research done on this subject, and the conclusion is that trying to lose weight just by working out doesn't, uh, work out. There are three main reasons why this is the case:

Eating is easier than working out. Eating X calories is a lot quicker and easier than exercising away X calories. There's a lot of inherent trickiness of knowing how much you burn (pro tip: whatever your fitness tracker says, it's probably way more than you actually burn), but if we say it's somewhere between 50-100 kcal/km, it means you have to run somewhere between 5.5-11 km (≈ 3.4-6.8 miles) to burn off the 550 kcal in a Big Mac. Oh, and if you had soda (210 kcal) and fries (320 kcal) with your burger, you'd basically have to double the workout.

Working out makes you hungrier. Your body will notice the energy expenditure and try to replenish its reserves. If you just eat until you're not hungry (i.e. no calorie restriction), you'll likely eat enough to compensate (or maybe even over-compensate) for whatever you lost during workout. (If you're an elite-level athlete this may not be true, but they are exercising for several hours per day, on average.)

Working out lowers your non-exercise energy expenditure. Contrary to popular belief, exercise does not make you burn more during the rest of the day - you'll burn less. This could be because of conscious actions (taking the elevator instead of the stairs because your legs are really tired after that long run), by unconsciously reducing activity (you get up out of your chair fewer times during the day because your body doesn't tell it wants to move since it already did), and even through fully involuntary mechanisms (i.e., your basal metabolic rate dropping).

(This is called the constrained energy model.)

If you want to lose weight, or more specifically lose body fat, these should be your priorities, in order of importance:

  1. Restricting calorie intake, since a calorie deficit is the only way you'll actually lose body mass
  2. Strength training and a high protein intake, since they both improve the ratio of fat to muscle lost (not much point in losing weight if it's mostly muscles - relatively speaking, you'd be fatter afterwards!)
  3. Cardio, but more for the general positive health effects than for the calories it burns (although it may give you a little more wiggle-room with the calories)

Edit to address OP's edit:

What I faced in while I restricted my calorie intake(even by keeping high amount of protein intake) was more muscle pain, lateق recovery and having not enough energy to workout as before, by the end I felt I am loosing muscle even more than fat!

Why do you think you were losing muscle? It's perfectly normal to feel weaker than usual when cutting; I mean, you are basically starving yourself. A cut isn't something you do for its inherent fun, I'm sorry to say.

You have to consider that when you're on a calorie deficit that the maximum training volume you can tolerate decreases, so you might need to lower it a bit (decreasing weights, doing fewer sets and/or reps). Sounds like this might've been the case for you.

However - since you wrote in a comment to a recent post on a similar subject that you had lost 2-3 lbs, you may have lost neither muscle nor fat - 2 lbs can easily be accounted for by hydration, how much and what type of food you have in your guts, how much glycogen you have stored in liver and muscles, and probably more that I forgot.

Personally, I've noticed that my own weight can easily vary about 1% from day to day when I'm in calorie balance. If I recall my bro-science correctly, the recommended rate of weight loss is roughly about 0.5%/week (so 1 lb/week if you're 200 lbs; more than that and you'll start losing more muscle), so even if you're doing things right it'll be hard to tell if you really lost weight any for the first two weeks, or if it's just the usual fluctuation. My advice is to weigh yourself often (every day in the morning, after any toilet visits but before breakfast), plot the results, and look at the trend rather than what the scales happen to say this particular morning.

The only thing that will see you losing weight is a calorie deficit. This is the hard, cold, nonnegotiable truth. You can certainly try to achieve that by lots of cardio and unrestricted eating. If you're like most people, it won't work because your body will trick you into compensating for the calorie loss, through a combination of eating more, doing less non-exercise activity, and lowering your metabolism. If it does work for you, well, congratulations, you achieved a calorie deficit without a conscious calorie restriction.

As for losing fat, I guess that if you are in calorie balance and you do proper strength training, your body should slowly recomposition to less fat and more muscle. Might take a while though (and it will likely be slower the less flabby you get), so don't count on sixpack abs this summer if you start now.

  • 1
    I like this answer. I would add empty calories(sugars) need to be eliminated, e.g. soda, fruit juice, orange juice, white bread. Second, increase of fiber rich foods to feel full such as oranges and berries, and increase of moderately fattier protein rich foods (leaner steaks, nuts, salmon), e.g. skinless chicken breast healthy, but probably will not fill you up.
    – paulj
    Commented Apr 4, 2022 at 12:53
  • @paulj How to successfully implement a calorie restriction is hard, but yeah, I whole-heartedly agree on avoiding sugar-rich drinks and white bread, and instead upping things that give a high level of satiety and nutrients per calorie. (Fibers and protein give a lot of satiety. It also helps if it's a bit boring, not too tasty, to help resist the urge for taking seconds.)
    – gustafc
    Commented Apr 4, 2022 at 13:10
  • @gustafc: I am also agree with you but have a comment that I have wrote on the EDIT part of the question. Commented Apr 5, 2022 at 18:34
  • Based on some people's experience, they cycle between an "eating less exercise less" and "eating more exercise more" phase, to burn the fat off both ends so to speak. It helps prevent a stall
    – user32213
    Commented Apr 7, 2022 at 17:16

When it comes to losing fat, both less calorie intake and more cardio can be effective. However, which one is more effective depends on the individual. For some people, reducing their calorie intake may be more effective for fat loss. For others, doing more cardio may be more effective. Ultimately, the best way to determine what works best for you is to experiment with both and see what gives you the best results.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.