I’ve received my fair share of questions over the years, and one of the more common ones is:

“Should I lift weights or do cardio to lose fat?”

So, I’m dedicating this week’s newsletter to answering the question as best as possible. Let’s take a look.

What Does It Take to Lose Weight?

Losing weight is about creating and sustaining an energy deficit (1). For example, if you burn 2,700 calories on average, consuming 2,200 calories per day would put you in a 500-calorie deficit, resulting in weight loss.

The interesting thing is that you can achieve the necessary deficit and start losing weight without any structured exercise. All you have to do is eat less food, and you’re good to go. 

Fat Loss Is Different

While people often use ‘fat loss’ and ‘weight loss’ interchangeably, the two don’t necessarily mean the same thing. Weight loss refers to dropping scale weight, which can come from several things: water, glycogen, muscle, fat, etc. You can drop scale weight, but it doesn’t necessarily mean you’re getting leaner. In contrast, fat loss refers to breaking down fatty tissue for energy.

Achieving the former is straightforward: be in a deficit. But, the latter is more challenging and requires more than just a deficit. Optimal fat loss occurs when you:

• Maintain a small to moderate deficit (2)
• Eat enough protein (3)
• Get enough sleep (4)
• Do the right amount (and type) of physical activity (5)

The Role of Physical Activity In Fat Loss

To understand why the above question isn’t the one you should ask, we first have to know why we exercise in the first place. The way I see it, there are two primary reasons for any form of training during fat loss:

• Preserving muscle
• Increasing your calorie expenditure (i.e., burning calories)

Certain individuals (such as overweight beginners) can also build muscle while losing fat, a process known as body recomposition.

The first reason is straightforward. You train your muscles and cause a stimulus that tells your body, “Hey! Muscle is valuable, and I don’t want you to be breaking it down for energy.” As a result, you maintain more of your muscle and instead lose primarily fat.

The second reason for exercising is to burn calories and increase your total daily energy expenditure, making it easier to achieve and sustain a calorie deficit for weight loss.

Cardio or Weight Training For Fat Loss?

Of the two, weight training is more critical during fat loss, not because of the caloric burn, but because it helps you preserve muscle. The process is relatively straightforward. Weights cause a stimulus, signaling to your body that muscle is necessary and should not be broken down for energy. As a result, you lose mainly fat (provided you sleep well and get enough protein) and achieve a lean and athletic physique.

Cardio can also be helpful for fat loss because it burns calories, making it easier to sustain the necessary deficit. Still, there are a couple of issues with aerobic exercise. First, doing too much cardio can interfere with your recovery, leading to a drop in weight training performance and a higher risk of muscle loss (6). Second, some people experience increased hunger from cardio and end up ‘eating back’ the calories they burn through aerobic exercise (7).

So, focus on weight training and include a bit of cardio if you feel it can speed up fat loss without impacting your recovery or overall food intake.

Thank you for taking the time! Until next week,
Philip

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