Recently, one of my clients asked me a common question within the fitness world. The age old debate of cardio versus strength training for weight loss.
To many, exercise may seem like nothing more than being more “physically active”. They believe if they are more active (whether that be on a treadmill or in the free weight section of a gym), they’ll lose weight.
But this isn’t the case necessarily. Because in my book, the goal should never be just weight loss. It should be sustainable weight loss. I mean, who wants to exercise and lose weight just to gain it all back down the road?
If you work hard for your results, you want to make sure you keep them for the long haul, right?
If that’s your objective, then the question becomes “Which is better for sustainable weight loss, cardio or strength training?”
In short, the answer to this question lies in a blend of these two exercise methods. So, let’s look at why that is the case.
1. A cardio-only weight loss approach results in loss of muscle mass overtime.
The main problem behind cardiovascular weight loss programs is they don’t stimulate muscle maintenance or growth.This is extremely important because of two reasons.
The first is, the more muscle mass you have, the more calories you’ll burn on a daily basis. Think about muscle mass like your car engine. The bigger your engine, the more gas it uses when traveling. If you don’t have a lot of muscle mass, you’ll burn less calories throughout the day resulting in less weight loss and fat loss.
And the second is, sustainable results are much easier to come by if you have more muscle mass. Here’s a scenario to put this into perspective.
Let’s say you have two males each weighing 200 lbs. The first male has 130 pounds of muscle and 70 pounds of fat. But the second has 170 pounds of muscle and 30 pounds of fat. Of these two, which one will burn more calories? The second, because he has a larger amount of muscle. So, both of these guys weigh the same but the second one will burn more calories simply from having some extra muscle mass.
This is why cardio-only approaches often fail. And the bad thing is, they can actually result in a loss of muscle overtime (1). If you don’t decrease your calorie intake to offset this reduction in muscle mass, then weight gain occurs.
2. Strength training preserves muscle mass.
Strength training (i.e. lifting weights) is an entirely different approach because it does stimulate muscle maintenance and growth. In order to grow and maintain our muscle mass, our bodies must be subjected to the right kind of stress. Fortunately, lifting weights is the perfect stressor.
A study done in 2008 demonstrated this (2). The researchers had three groups of women participate in three separate training protocols.The first group did aerobic training only, the second did resistance training only, and the third did no exercise at all.
They also had them on a calorie restricted diet. And this is an important part of the study because a drop in calories will result in weight loss. The researchers wanted to see how this decrease in calories affected their muscle mass.
By the end of the study, they found that each group lost weight, which was expected. But, they also found that the aerobic-only and non-exercise groups both lost muscle mass. The resistance group, on the other hand, maintained their muscle mass throughout the duration of the study.
The authors of the study also found that the aerobic and non-exercise groups decreased the amount of calories they burned at rest while the resistance group did not. Going back to our first point, this is important to the sustainability of your weight loss and fat loss results.
3. While it can be argued which one is better, a blend of both approaches seems to work best.
While it may sound like I’m hating on cardio, I do believe it has it’s place in a weight loss training program.
In the fitness world, many people lie on one side of the fence. And if you disagree with them, you’re thought of as ignorant or misinformed. But these are often the people who take themselves way too seriously and only believe what they want to believe.
One camp will tell you, you have to do more cardio to lose weight. Another may tell you cardio is a joke and you just need to lift weights. But, as our research into this question would have it, using both forms of exercise seems to be the best option.
In 2013, a group of researchers surveyed 15 different studies of over 700 participants that looked at resistance training, aerobic training, and a combination of the resistance and aerobic training as a treatment for obesity. After carefully looking at each one, they found that a combination of both is the best method to change body composition and prevent obesity (3).
Wrapping Up
The debate of cardio versus strength training for weight loss, will go on and on. As the research shows though, both are important. Remember, the more muscle mass you have the easier it is to sustain your weight loss over time. And that’s the name of the game, sustainability.
A cardio-only approach won’t help you do this. So don’t make the mistake of thinking all you need to do is run and you’ll lose weight. It comes down to blending a well-rounded strength training program with a cardiovascular fitness program. In the long run, this produces the best results and helps you maintain those results.
References:
1. Wescott, WL. et al. Prescribing physical activity: applying the ACSM protocols for exercise type, intensity, and duration across 3 training frequencies. Phys Sportsmed. 2009 Jun;37(2):51-8.
2. Hunter, GR. et al. Resistance training conserves fat-free mass and resting energy expenditure following weight loss. Obesity (Silver Spring). 2008 May;16(5):1045-51.
3. Schwingshackl L. et al. Impact of different training modalities on anthropometric and metabolic characteristics in overweight/obese subjects: a systematic review and network meta-analysis. PLoS One. 2013 Dec 17;8(12):e82853.
