The Best Way to Train for Fat Loss & Body Composition

The role that exercise plays for fat loss has been a topic of debate for a while now.

Some claim that exercise is besides the point and fat loss is only a function of nutrition.

Some claim that cardio is the best form of exercise for fat loss.

Some claim that lifting weights is your best bet for fat loss.

Well, a systematic review was published in May of 2025. [1]

It seems to provide a definitive answer on the topic.

So, this article will explain:

• The basic requirements for weight loss to occur

• Weight loss vs fat loss (they’re different!)

• The background rationale for strength or cardio being useful for fat loss

• The findings of this new review

• Practical applications to take home

Conditions required for weight loss to occur

Whenever we’re discussing weight loss of any sort, it is worthwhile to first address energy balance.

Each day, take in a certain number of calories through food and drink.

Similarly, you expend a certain number of calories each day through breathing, your heart beating, thinking, digesting food, fidgeting, typing, walking into the grocery store, exercising, etc.

• Calories are just a unit of measurement for energy. Similar to how an inch is a unit of measurement for distance.

The mathematical balance between the energy that comes in versus the energy spent dictates whether you gain, lose, or maintain your weight.

If you expend more energy then you consume in a day, your body is forced to turn to its own stores of energy to keep the lights on.

If you consume more energy then you expend in a day, your body will store the extra energy for use later.

If your consumption and expenditure of energy is the same, then your weight will remain the same.

However, this mathematical balance between energy in and energy out only dictates what happens to body weight in general.

When it comes to what kind of weight you lose or gain, there are various other factors to consider.

Weight loss vs fat loss (they’re different!)

As we just discussed, the reason you lose weight is because your body needs fuel that it isn’t getting from your diet.

So, it must turn to its own energy stores.

However, your goal should never be to simply lose weight. Your goal should be to lose fat specifically.

This may be obvious, but it’s still worth bringing up the pertinent factors.

These include:

• Strength training (tells your body why you need to maintain muscle)

• Sufficient protein intake (gives your body the substrate to maintain the muscle)

• A moderate deficit of calories and slower rates of weight loss (rapid weight loss will force your body to burn muscle as well as fat)

The rationale for strength training for fat loss

Strength training is crucial when losing weight because it is the primary variable that will ensure you lose fat specifically and not muscle or other tissue types.

However, there’s another reason why strength training is considered helpful for fat loss and body composition.

Muscle is a metabolically active organ. In other words, the more you have, the more calories you burn by default.

The actual amount of calories burned by muscle is somewhere in the ball park of ~6-10 calories per pound. [2]

So, if you put on 10 pounds of muscle, you’ll burn an extra 60-100 calories per day.

If you put on 20 pounds of muscle, you’ll burn an extra 120-200 calories per day.

Now, this isn’t a life-changing number, but it’s not completely negligible either.

Putting on 10-20 pounds of muscle takes a long time. Multiple years for most people.

However, ideally you’ll strength train in some way, shape, or form the rest of your life.

So, assuming this is the case, you will over time take advantage of this benefit.

Some have speculated that strength training demands a greater energy expenditure for recovery compared to cardio (excess post-exercise oxygen consumption, EPOC).

However, the actual difference between the two is small enough to be considered negligible. [1]

So, I do not consider it a unique benefit for strength training in this regard.

The rationale for cardio for fat loss

Cardio can be helpful for fat loss in two different ways.

First, cardio burns more calories than strength training per unit of time.

For instance, a 60 minute run may burn anywhere from 400-800 calories or more (depending on pace).

A 60 minute strength training session may burn 1/4 to 1/2 of this amount.

Second, cardiovascular training improves your body’s ability to use fat for fuel. [3]

Imagine you had two people run a 5k.

One person is untrained cardiovascular, and the other person is highly trained cardiovascularly.

The untrained person would derive almost all of their energy from stored carbohydrate, whereas the highly trained person would use a more even split of carbs and fats for fuel.

True physical fatigue sets in once your carbohydrate stores are depleted.

The better your body is at using fat for fuel, the longer your carbohydrate stores can lost. Therefore, fatigue is delayed.

This is why one of the primary ways you improve in cardio is by utilizing fat for fuel more efficiently.

Some have speculated that this would translate to weight loss endeavors as well.

In other words, when you go into a deficit of calories, your body will be able to use its stored fat for fuel more easily.

What the evidence says is best

In May of 2025, the Journal of the International Society for Sports Nutrition published a systematic review w/ meta-analysis that sought to provide an answer to what kind of exercise is best for fat loss. [1]

They studied strength training, cardio, or both done together (concurrent training).

They looked at total weight loss, fat loss specifically, and fat free mass retention (muscle retention).

In short, the major findings are as follows:

• Aerobic training alone led to the greatest total weight loss.

• Fat loss from aerobic training was significantly greater than from strength training.

• Fat free mass retention was better in resistance training than it was in endurance training.

• Fat loss specifically was similar between aerobic training and concurrent training.

• Fat free mass retention was similar between concurrent training and strength training.

So, the bottom line is this: doing both resistance training and cardio is the best way to exercise for fat loss and body composition altogether.

If I were to add my two cents to the picture: I would guess that it is the combination of everything we talked about previously (rationales for strength or endurance training for fat loss) that are contributing to these results.

Practical take-homes

Much of the free content I provide discusses why you should do both strength and endurance training, as well as how to go about combining them.

The information provided here serves as another reason why doing so is important.

So, the major take-home from this article is the following:

• If you currently only strength train, consider dabbling in some endurance training.

• If you currently only endurance train, consider dabbling in some strength training.

• If you currently do neither… then I’m sure you could guess my recommendation.