Weight Loss: Cardio or Weight Lifting, Which is Better?

Weight Loss: Cardio or Weight Lifting, Which is Better?

When it comes to fitness goals many people choose weight loss as a common theme to track their progress.  As physical therapists we want to squash this conception that tracking your weight is a good way to create a fitness goal.  Let’s outline why weight loss should not be your focus when it comes to fitness goals.

To start off, having a weight loss goal is a slippery slope.  One main reason for this is that when people reach their weight loss goal they stop their workout routine and often gain the weight back.  Additionally, if you’re doing a resistance training program you may actually gain weight instead of losing weight because muscle weighs more than fat.  Weight loss goals are common for most individuals, but shouldn’t be your main goal when starting a fitness program.  With that being said let’s chat about the headline: Cardio vs. weight lifting.

First let’s outline the basics.  Weight loss is a simple equation, in order to lose weight your body needs to burn more calories than it takes in.  It sounds simple enough, but is usually much easier said than done.  There is more that goes into this equation than just activity level though, like nutrition, but that’s a conversation for another time.  Developing consistent habits for activity is critical for burning calories to lose weight.  Now this leads us back to the original question, cardio or weights?

As you may have surmised the answer is not quite as easy or simple as many would like it to be.  Here are some things to consider if you compare the amount of calories burned during a 30 minutes cardio session to a 30 minute weight lifting session, cardio wins.  However, when the exercise is done cardio provides no more benefit for weight loss.  This is usually how people look at their exercises which is why many people who do weeks of cardio don’t see a drop in their weight.  However, the calories burned during a workout is only a portion of the overall equation.  When you lift weights the calories you burn during the activity pales in comparison to cardio, however when you’re done lifting weights your body will continue to burn calories for up to an additional 48 hours after the weight lifting session. Let’s talk about how this works.

  1. Lifting weights recruits more muscle fibers than cardio.  During cardio we mostly use Type I muscle fibers which are good as sustaining activity for a long duration.  Type II muscle fibers are recruited during weight lifting activity and are energy hungry, they burn through energy at a much greater rate than the Type I fibers.  Additionally, when we struggle to lift weights our body has to recruit a larger number of fibers to complete the task thus burning more energy (calories).

  2. The strain created during weight lifting actually creates micro-tears in the muscle fibers.  During the next 48 hours after activity your body has to repair these micro-tears and must burn extra calories for this process.

  3. Muscle is energy hungry, or in scientific terms, metabolically active.  This means that your body has to expend more energy to sustain muscle mass and burns calories to make this happen.  Therefore, the more muscle mass your body has to sustain the more energy (calories) your body has to burn just to maintain itself.

What’s the secret to weight loss?

As physical therapists we get asked this question a lot.  Additionally, we also get questions like: 

  • What type of exercise should I do at the gym?

  • Is strength training good for me?

  • Is running a good way to lose weight?

  • Should I start cycling or swimming?

In order to address these questions, we would like to point out that the best exercise for you is one that you’ll actually do.  If you hate going to the gym, don’t get a gym membership.  If you hate running, don’t start a running regimen.  The best way to create fitness goals is to create a plan that includes activities that you actually enjoy.  With that being said, almost everyone should incorporate some form of strength training into their fitness programs.  The benefits of strength training can not be overstated enough.  Regular strength training will not only contribute to your overall fitness, but will allow you to stay mobile and independent into your golden years and keep you away from the dreaded walker or wheelchair.

Take Away Points

To sum it all up, which is better for weight-loss, cardio or weight lifting?  I would say both are good choices and each have their merits, but I believe the key to weight loss is consistency.  Cardio burns more during activity, but weight lifting may end up burning more overall calories due to post exercise metabolic effects. Doing activity regularly is the key, and being honest with yourself about your commitment.  Say you're planning on doing workouts 5 days a week, but really only committing 10 minutes of light activity every other day.  This won’t get you where you want to be and you’re not being honest with your commitment. By incorporating both weights and cardio into your fitness program you get the benefits of the robust calorie burning during cardio as well as the long term calorie burning effects of weights.


CRAIG STEPHENS