Cardio Resistance Training

Cardio vs. Resistance Training: Optimizing Exercise for Weight Loss

May 21, 2025

As a medical weight loss specialist, I'm often asked by patients about the best type of exercise for losing weight. The question usually boils down to this: "Should I focus on cardio or resistance training?" It's a great question, but the answer isn't as straightforward as you might think. Let's dive into the science behind both types of exercise and explore how they contribute to weight loss.

Ideal Approach: Cardio & Resistance Training

First, it's important to note that the ideal approach to exercise incorporates both cardio and resistance training on a consistent basis. This combination yields the best overall health outcomes (1). However, when weight loss is the primary goal, we need to look at each type of exercise more closely.

Let's start with cardio. Many people intuitively assume that cardio is superior for weight loss, and there's definitely merit to this thinking. Cardiovascular exercise significantly elevates your heart rate and energy expenditure. To put it in perspective, a person weighing about 155 pounds can burn anywhere from 300 to 550 calories in a 30-minute cardio session (2). What's more, the benefits don't stop when you step off the treadmill or finish your swim. Your metabolism stays elevated for hours after cardio exercise, anywhere from 1 to 30 hours depending on the intensity of your workout.

Speaking of swimming, I often recommend aquatherapy for patients with joint issues. It's an excellent form of cardio that's gentle on the joints. Even if you're not a swimmer, simply walking in water provides great resistance and helps burn calories effectively. 

For more information about aquatherapy, here is my prior blog: Learn more about aquatherapy.

Resistance Training

Now, let's talk about resistance training. While it may not burn as many immediate calories as cardio, it offers some crucial benefits that shouldn't be overlooked. Resistance training is key for building and maintaining muscle mass, which in turn helps preserve your metabolic rate. It's also great for supporting bone health. These factors become especially important when we're thinking about long-term weight management and overall health.

The conversation gets even more interesting when we factor in weight loss medications. These medications can accelerate weight loss, but they come with a potential downside: muscle mass loss (3). This is where resistance training becomes absolutely crucial. It helps mitigate this muscle loss and the associated negative effects, which can include weakness, decreased metabolism, and reduced bone density.

So, what's the bottom line? If your sole focus is losing weight as quickly as possible, cardio is generally more effective. However, if you're looking to preserve muscle and maintain a healthy metabolism, resistance training is key. For optimal results, I recommend combining both types of exercise if your schedule permits.

Weight Loss Medications

For patients using weight loss medication, I strongly emphasize the importance of incorporating resistance training into their routine. It's vital for preserving muscle mass while you're in a calorie deficit.  For more information, read my previous blog, Read more about muscle mass loss.

Remember, the best exercise regimen is one that you can maintain consistently. It's always better to do something rather than nothing, so find activities you enjoy and can stick with long-term.

As with any significant changes to your health routine, I always advise consulting with your healthcare provider before starting a new exercise program or weight loss medication. They can help tailor recommendations to your specific health needs and goals.

Stay Healthy, Stay Strong, - Dr. Leon Katz

References:

  1. Role of Physical Activity for Weight Loss and Weight Maintenance, Carla E. Cox.  ©2017 by the American Diabetes Association - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556592/pdf/157.pdf
  2. Mayo Clinic https://www.mayoclinic.org/healthy-lifestyle/fitness/expert-answers/exercise/faq-20057916
  3. Weight Loss Strategies and the risk of skeletal mass loss - David McCarthy, Phd and Aloys Berg, Phd. Nutrients 2021, 13, 2473 - https://pmc.ncbi.nlm.nih.gov/articles/PMC8308821/

Dr. Leon Katz MD, FACS, FASMBS, is a bariatrician specializing in non-surgical, medically supervised weight loss. Dr. Katz currently practices at Dr. Leon Katz Medical Weight Loss Center.

Cardio Resistance Training
Leon Katz

ABOUT THE AUTHOR

Dr. Leon Katz MD, FACS, FASMBS, is a bariatrician specializing in non-surgical, medically supervised weight loss. He focuses on patients seeking alternatives to surgery and those needing care after bariatric procedures. Dr. Katz was recently the director of a major medical weight loss program. With extensive experience in establishing successful weight management programs, he now concentrates exclusively on non-surgical weight loss solutions. Dr. Katz is a Diplomate of the American Board of Obesity Medicine and Fellow of American College of Surgeons. Dr. Katz currently practices at Dr. Leon Katz Medical Weight Loss Center.
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