Is Cardio Good for Weight Loss?

We've all seen it before: the new year arrives, and everyone is committed to losing weight. You go to the gym, and there isn’t a single soul not running their tails off on the treadmill trying to get rid of that stubborn belly fat. While this may lead to initial weight loss, it’s a problematic approach. So, controversially, I'd like to examine the question: is cardio good for weight loss?

The Two Main Types of Cardio

First things first, it’s important to acknowledge that the type of cardio you perform can fall under two categories:

• Steady State Cardio: This involves maintaining a consistent, moderate-intensity level of exercise for an extended period. Common examples include incline walking, jogging, or cycling at a steady pace. This type of cardio aims to keep your heart rate within a specific target zone for an extended duration, promoting endurance and burning calories over time. During this form of cardio, fat is the body's preferred source of fuel

• HIIT (High-Intensity Interval Training): This, on the other hand, is a more intense and time-efficient form of cardio. It alternates between short bursts of high-intensity exercises and periods of rest or lower-intensity activity. For example, you might sprint for 30 seconds and then walk for 30 seconds, repeating this cycle. This type of cardio can help burn calories in a shorter time, temporarily boost metabolism, and improve cardiovascular fitness. During this form of cardio, carbohydrates are the body's preferred source of fuel

Cardio and Metabolic Adaptation

Excessive cardio places stress on the body, and our bodies are highly efficient at adapting to stress. If your goal is to lose weight and the first thing you do is spend an hour a day on the treadmill, it may initially create a calorie deficit, and you'll probably see the scale go down since your body is working to burn more calories than it consumes. But over time, your body adapts to this specific form of stress, and the initial effectiveness in creating a calorie deficit diminishes.

With consistent cardio, your body becomes efficient at conserving energy, meaning your body can perform the same task using less energy, resulting in burning fewer calories. This adaptation leads to a slowdown in your metabolism. This efficiency means that the same amount of cardio that initially led to a calorie deficit might not have the same impact over time. Once your body is "adapted," you might find that seeing further results requires you to increase the amount of cardio you perform. For many, this is a challenge because they already start with such an intense amount.

Unfortunately, this response makes weight loss more challenging. This is because your body learns to operate on fewer calories, meaning it burns less, in turn making it harder to achieve your weight loss goals

Cardio and Muscle loss

Engaging in excessive cardio, particularly prolonged and intense sessions, can lead to the breakdown of muscle tissue for energy. This effect is known as 'catabolism,' which refers to the process of breaking down complex molecules into simpler ones—in this context, the breakdown of muscle tissue.

Losing muscle mass not only decreases overall strength and fitness but also negatively impacts metabolism. Muscle is considered an 'active tissue,' requiring energy (calories) for maintenance. So, the more muscle you lose, the fewer calories your body burns, making weight loss more challenging. This explains why your priority should be to maintain or, in some cases, even build as much muscle as possible during weight loss.

Excessive cardio, regardless of type, can also interfere with your body's ability to recover properly from one training session to another. Our capacity for recovery is limited and exceeding that limit can lead to decreased performance and, once again, the risk of muscle loss.

Cardio and cortisol levels

Excessive cardio routines can also elevate cortisol levels, which is your body's stress hormone, linked with an increase in appetite. As cortisol rises, it can influence your appetite by triggering cravings for sugary and high-fat foods.

This was demonstrated by a study conducted by Epel et al. (2001) investigating the relationship between chronic stress, cortisol levels, and dietary preferences. The researchers observed that individuals experiencing chronic stress displayed a preference for energy-dense foods, particularly those high in sugar and fat, suggesting a potential link between elevated cortisol levels indicative of prolonged stress and altered dietary habits favoring calorie-dense options.

This hormonal response is part of the body's mechanism, where stress would indicate a need for quick and easily accessible energy sources. Consequently, this heightened cortisol-induced appetite can undermine your weight loss efforts, as increased consumption of calorie-dense foods can counteract the calorie deficit created by cardio exercise.

Cardio Makes You Hungry

Extended cardio sessions can trigger hunger by lowering your blood sugar levels. Understanding this response is crucial for managing your post-cardio eating habits. The body's tendency to crave quick sustenance after a cardio workout adds another layer of challenge. Unfortunately, this craving often results in consuming extra calories, potentially undoing the calorie burn achieved during the workout.

Consider a 30-minute run on the treadmill; an average person can burn anywhere between 300-400 calories doing so. However, this effort can significantly ramp up your appetite, and the calorie burn achieved may be easily undone by eating a simple sandwich. So, you've got to ask whether all that extra cardio you're doing is worth it.

Unsustainability

Relying solely on cardio for weight loss raises concerns regarding its long-term sustainability. Achieving weight loss through endless high-intensity cardio sessions might be effective initially, but the challenge lies in maintaining such efforts indefinitely. For many, the prospect of continuing intense cardio sessions forever is daunting.

A more effective approach is to strategically incorporate cardio towards the end of your weight loss journey, particularly to overcome the inevitable plateaus you will encounter as your body fat percentage gets lower and lower, requiring extra efforts to reach your goal. This doesn't mean you should completely avoid cardio but suggests saving it for specific phases. If there's a form of cardio that you genuinely enjoy and envision yourself doing consistently throughout your life, feel free to include it in your routine.

This recommendation is specifically for those who engage in extended cardio sessions in the hope of reaching their dream body. It's important to recognize that such practices may not be sustainable in the long run.

This blog post isn't intended to be anti-cardio. If there's a form of cardio you genuinely enjoy and can see yourself doing long-term, incorporate it into your weight loss efforts by performing it after your resistance training sessions. But, if you're not a fan of cardio and your goal is to lose weight, I recommend avoiding it and creating your caloric deficit through diet instead. Near the end of your weight-loss journey, it often becomes harder to lose fat in stubborn areas. This is when you should save cardio, much like holding back cards in a game of poker—you always want to keep an ace up your sleeve.