Strength vs. Cardio: Which Is Better for Fat Loss?

When I first started teaching exercise, it was all about cramming as much cardio as possible into a session. I loved teaching Turbo Kick, kickboxing, and step classes. I also put myself on a treadmill for 60 endless minutes, thinking it was the only way to lose the 25 pounds I gained in college.

But when it comes to fat loss, which is actually better – strength training or cardio? And if you’re in a time crunch, which one should you prioritize?

When you start exercising, you lose fat and gain muscle, but here’s the kicker: muscle is denser than fat. Pound for pound, muscle takes up less space than fat, so while the scale might not change much, your body will shrink and look more toned.

This is why scales can’t always tell the whole story. Muscle is 74% water, fat is 10-15% water. So naturally it’s heavier. Instead, pay attention to how your clothes fit, how you feel, and how strong you’re becoming.

Strength vs. Cardio: What the Science Says

Study #1: Diet + Strength Training = Best Fat Loss

This study looked at premenopausal women in three groups:

1. Diet only

2. Strength training only

3. Diet + strength training

Who lost the most fat?

   The group that did diet + strength training together had the most significant fat loss.

   The diet-only group came in second.

   The strength-only group had the least amount of fat loss.

Study #2: Strength vs. Cardio for Fat Loss and Muscle Building

This study compared three groups:

1. Strength training only

2. Cardio only

3. Cardio + strength training

Body weight and fat mass decreased the most in the cardio-only group and the cardio + strength group.

The strength-only group didn’t lose much fat, just like in the first study.

Which Should You Prioritize When You’re Short on Time?

If your goal is to change your body composition – losing fat while maintaining muscle – you need a balance of both.

Here’s your ideal weekly schedule:

Strength training 3x per week (30-35 minutes per session)

Daily movement. Walk every day, get your steps in.

If you prefer, add 2 HIIT cardio sessions (15 minutes each)

Strength training preserves muscle and metabolism, while walking keeps you active and burning calories without over-stressing your body.

No time for both? Prioritize walking.

Strength Training Is a Game-Changer (Especially for Women 35+)

If you’re over 35, you’re losing muscle mass at a rate of 3-8% per decade. Strength training isn’t just about looking aesthetics, it’s about staying strong, maintaining metabolism, and aging well.

Your fitness watch can’t track everything, especially the long-term benefits of strength training. Here’s what it won’t tell you:

1. Strength Training Boosts Your Metabolism

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at rest. As you age, your metabolism slows, largely because you’re losing muscle. Strength training reverses this.

2. Strength Training Triggers Afterburn (EPOC Effect)

After a strength training session, your body continues burning calories for up to 24 hours as it repairs muscle and replenishes energy stores. Your fit watch won’t capture this extra calorie burn, but it’s happening.

3. Strength Training Improves Hormone Balance

Increasing testosterone and growth hormone (supports muscle growth and fat metabolism). Reducing cortisol (stress hormone linked to belly fat)

4. Strength Training Supports Bone and Joint Health

Lifting weights strengthens bones, reducing risk and joint issues as you age.

5. Strength Training Improves Insulin Sensitivity

If you’ve heard of insulin resistance, you know it’s linked to weight gain and metabolic issues. Strength training helps your body process carbohydrates better, reducing fat storage.

The Mind-Body Connection: Strength Training and Mental Health

Did you know strength training releases hope molecules?

These myokines travel through your bloodstream, sending anti-depressant signals to your brain. Strength training has been linked to:

•  Lower stress and anxiety
• Enhanced mood and mental clarity
• Improved memory and learning

Final Thoughts: Strength vs. Cardio – Which One Wins?

Strength training and cardio together = best results

When life gets busy and you can’t do both, just keep moving. Walk daily, eventually aiming to stay consistent with strength training, and focus on progress, not perfection.

Your body and future self will thank you.

[1] ACSM’s Guidelines for Exercise Testing and Prescription, eleventh edition.
[2] American College of Sports Medicine. Progression models in resistance training for health adults.
[3] PMID: 28834797.
[4] PMID: 33671664; PMCID: PMC7927075.
[5] PMID: 22533517.