What Is Cardio? Redefining Cardiovascular Fitness

When most people hear the term “cardio,” they think of moderate exercises like running, swimming, or rowing for at least 20 minutes. But cardio—short for cardiovascular—deserves a deeper look. Rooted in the Greek word kardia, meaning “heart,” cardio is about much more than just extended exercise sessions. It’s about optimizing your heart and lungs to perform at their best.

Surprisingly, few discussions about cardio include strength training, a critical component of true fitness. Let’s redefine what cardio really means and why it’s essential for everyone—because, as Nike co-founder Phil Knight once said, “If you have a body, you are an athlete.”

Cardio Is More Than the Treadmill

Cardio isn’t just about time spent on a treadmill or elliptical machine. While these methods are common, they have limitations. For example, running creates beneficial impact, improving circulation and increasing bone density. In contrast, the elliptical reduces impact, which might feel easier but sacrifices some of these health benefits.

God designed our bodies for movement—dynamic, impactful movement that strengthens both bones and muscles. Activities like running, jumping, and strength training align with this design, helping to build a stronger frame and a more powerful heart.

How Does Cardio Impact Performance?

To increase performance, think of your body as a finely tuned machine. To improve that machine, you would:

• Decrease weight to improve efficiency.
• Strengthen the frame to enhance durability.
• Boost the engine—your heart and lungs—for more power.

Cardio plays a vital role in this process, especially when performed at the right intensity. Low to moderate intensity barely scratches the surface of what’s possible. To truly build cardiovascular endurance, you need to push your heart rate to around 150 beats per minute or 65% of your VO2 max. This zone helps your body burn fat efficiently—up to 60% of the energy used during exercise comes from fat.

When you push harder (75% of VO2 max or higher), your body shifts to glycogen for energy. While this may sound intense, your body has the reserves to sustain high-effort workouts for over two hours. Ultimately, fitness comes down to calories in versus calories out. Pushing your body hard and fueling it with high-quality nutrition yields the best results.

The CrossFit Approach: Cardio Reinvented

At CrossFit, we redefine cardio as “cardio weightlifting.” Instead of limiting ourselves to monotonous routines, we:

• Lift weights hard and fast.
• Combine strength and endurance through running, rowing, and jumping.
• Embrace intensity to build stronger bones, muscles, and cardiovascular systems.

CrossFit athletes are heart-pounding, lung-pumping machines who outperform traditional cardio methods. Whether we’re lifting, running, or rowing, we push beyond the limits of treadmills and recumbent bikes. It’s not just cardio—we are cardio.

So, are you ready to rethink your approach to fitness? Stop limiting yourself to traditional definitions and embrace the full spectrum of what your heart and body are capable of achieving. You’re not just an exerciser—you’re an athlete.