Why You Should Do Cardio (Hint: It's Not For Weight Loss)

Justina Nothard
Jan 13
6 min read

Updated: Feb 4

When you think of cardio, is weight loss the first thing that comes to mind? What if I told you that cardio isn't about burning calories or shedding pounds? In fact, focusing on weight loss might be the least important reason to do it. Today, we'll explore the real reasons cardio is essential—reasons that could literally add years to your life.

Cardio exercise is one of the most misunderstood forms of movement. While it's true that cardio burns calories, research shows it's not the most effective way to lose weight. Our bodies are incredibly efficient at adapting to calorie expenditure, often compensating by burning fewer calories throughout the day or increasing hunger. But here's the thing—cardio is about so much more than weight loss. It's about longevity, brain health, energy, and living a vibrant life. Let's dive into six key benefits of cardio that go far beyond the scale.

You can also watch this video on my YouTube channel.

Cardio for longevity and heart health

Cardio acts as a workout for your heart, strengthening it over time and reducing the risk of cardiovascular diseases like heart attacks and strokes. Cardio improves your body's ability to deliver oxygen to vital organs and muscles. This reduces the strain on your heart by enabling it to pump blood more efficiently, lowering your resting heart rate over time. It's like giving your heart a tune-up that helps it last longer.

Dr Peter Attia refers to exercise as "the most potent longevity drug," and studies back this up by showing that improved cardiovascular fitness lowers the risk of early death. For example:

VO2 Max: This is a measure of how efficiently your body uses oxygen during exercise. People with higher VO2 max levels tend to live longer and healthier lives. Being in the lowest quartile for VO2 max can quadruple your risk of all-cause mortality compared to those in the top quartile. Think about that - 4 times greater risk of mortality, that's huge.

Practical Tip: Incorporate Zone 2 training—steady-state cardio at a pace where you can talk but not sing—to build aerobic endurance and improve mitochondrial efficiency. Activities like brisk walking, cycling, or swimming are excellent options.

Additionally, cardio improves arterial flexibility and reduces blood pressure. Over time, this can significantly reduce the wear and tear on the cardiovascular system, leading to a reduced risk of heart attacks and strokes.

Boosting metabolic health and energy

Cardio enhances metabolic flexibility, allowing your body to switch seamlessly between burning fat, carbohydrates, and ketones for energy. This adaptability is crucial for preventing metabolic disorders like type 2 diabetes. Here's why:

Mitochondrial Health: Cardio strengthens your mitochondria—the power plants of your cells—leading to better energy production and reduced fatigue in daily life. By improving mitochondrial function, cardio supercharges your cells' ability to produce energy. This means you'll feel less fatigued during daily activities and have more stamina for everything from work to workouts.
Insulin Sensitivity: Regular aerobic exercise improves how your body responds to insulin, lowering blood sugar levels and reducing the risk of diabetes.

Beyond improving insulin sensitivity and mitochondrial health, cardio also plays a role in reducing visceral fat—the dangerous fat stored around your organs that increases the risk of metabolic diseases. Research shows that aerobic exercise is particularly effective at targeting visceral fat, even without significant weight loss. This makes cardio a powerful tool for improving metabolic health from the inside out. Additionally, by enhancing oxygen delivery to tissues, cardio ensures that your cells have the energy they need to perform daily tasks efficiently, leaving you feeling more energised throughout the day and who wouldn't want better energy levels and fewer energy crashes?

Practical Tip: Start with moderate-intensity cardio sessions like jogging or dancing for 30 minutes three to five times a week. Over time, the aim is to include high-intensity interval training (HIIT) to further boost metabolic health.

Cardio for brain health and mental well-being

Cardio doesn't just benefit your body; it's also a powerful tool for maintaining mental sharpness and emotional balance:

Cognitive Benefits: Cardio increases blood flow to the brain, which supports memory, learning, and overall cognitive function. Regular exercise has also been shown to reduce the risk of Alzheimer's disease by up to 30%.
Mood Enhancement: Aerobic exercise triggers the release of endorphins—your body's natural mood elevators—and reduces stress hormones like cortisol. This can be as effective as antidepressants in alleviating symptoms of anxiety and depression.

Cardio's impact on mental health extends beyond mood enhancement—it also improves resilience to stress. Regular aerobic exercise has been shown to reduce activity in the amygdala, the part of the brain responsible for fear and anxiety responses, making you less reactive to stressors over time. Furthermore, cardio increases hippocampal volume, which is associated with better memory retention and learning capabilities.

Practical Tip: If you're feeling stressed or mentally drained, try a 20-minute walk or light jog outdoors. The combination of physical activity and exposure to nature can amplify these mental health benefits.

Improving sleep and recovery

Are you struggling with poor sleep? Cardio can help regulate your circadian rhythm by reducing stress hormones and promoting relaxation:

Deeper Sleep Cycles: Studies show that regular aerobic exercise helps you fall asleep faster and enjoy more restorative sleep phases.
Enhanced Recovery: By improving circulation, cardio aids in delivering oxygen and nutrients to muscles, speeding up recovery after physical exertion.

Cardio's benefits for sleep go beyond helping you fall asleep faster—it also improves sleep quality by increasing time spent in the deepest stage of sleep, where physical recovery occurs. This stage is critical for muscle repair, immune function, and overall recovery from daily stressors. Moreover, regular aerobic exercise has been shown to regulate melatonin production, a hormone that controls your sleep-wake cycle. These improvements make cardio an essential tool for anyone struggling with poor sleep or fatigue.

Practical Tip: Avoid intense cardio close to bedtime as it may disrupt sleep. Instead, schedule morning or early afternoon workouts to maximise these benefits.

Building stamina and functional fitness

Cardio isn't just about running marathons—it's about building stamina for everyday activities:

Everyday Strength: Whether it's climbing stairs or keeping up with your kids, improved cardiovascular fitness makes daily tasks easier.
Functional Longevity: Dr Attia describes this as training for your "Centenarian Decathlon," ensuring you maintain functional fitness well into old age.

Low-intensity steady-state cardio builds endurance over time, while HIIT improves VO2 max—both critical for staying active as you age.

Cardio doesn't just prepare you for physical challenges; it also improves your body's efficiency at utilising oxygen during everyday activities. This means you'll feel less winded climbing stairs or carrying groceries—tasks that can become increasingly difficult with age if fitness levels decline. Additionally, cardio enhances muscular endurance by increasing capillary density in your muscles, ensuring they receive adequate oxygen during prolonged activity. These adaptations make cardio invaluable for maintaining independence and mobility as you age.

Practical Tip: Alternate between low-intensity exercises like brisk walking or cycling on some days and high-intensity workouts like sprint intervals on others.

Cardio as an immune system booster

Did you know that cardio strengthens your immune system? Here's how:

Improved Circulation: Cardio enhances blood flow, helping immune cells travel more efficiently throughout your body.
Reduced Inflammation: Regular aerobic exercise lowers inflammation markers and clears out senescent "zombie" cells that contribute to chronic diseases.
Cellular Aging: Studies suggest that cardio may even slow cellular ageing by promoting autophagy—the process by which cells remove damaged components.

Cardio's immune-boosting effects are particularly relevant during cold and flu season or periods of high stress when immunity tends to dip. Moderate-intensity aerobic exercise has been shown to increase the circulation of natural killer cells—your body's first line of defence against infections and cancerous cells. Furthermore, regular cardio reduces chronic inflammation by lowering levels of C-reactive protein (CRP). Studies have highlighted how consistent moderate exercise enhances immune regulation while reducing harmful inflammatory responses, making it a cornerstone of long-term health maintenance.

Practical Tip: Consistency is key—spread your sessions across the week to maintain regular immune cell circulation and reduce inflammation. Avoid overtraining, as excessive high-intensity workouts can temporarily suppress immune function. Instead, balance your routine with recovery days and low-impact activities to allow your body to fully benefit from the anti-inflammatory and immune-regulating effects of exercise.

You've just learned how cardio can revolutionise not only your physical health but also your mental clarity, energy levels, and overall quality of life. But this is just the beginning! Imagine having a step-by-step guide to integrate these insights into your daily routine in a way that feels natural and achievable.

If this blog resonated with you and you're ready to take the next step toward improving your health and well-being, then check out the My BMB Program, where we dive deeper into topics like cardiovascular health, metabolic flexibility, and mental well-being. You'll learn actionable strategies via guided meditations, helping you not just incorporate cardio into your routine but also transform your mindset around health and fitness.