Let's be honest, most of us only perform cardiovascular activities to burn fat. Yeah, yeah, it's good for your heart and lungs, but many of us who take the time to do cardio are more interested in the aesthetic benefits. I'm not saying there aren't people out there who only care about the health benefits, but they are fewer and farther between. Cardio seems like such a simple thing to add to your fitness routine--you basically just hop on a machine and go for it, right? Well, not exactly, there are some basic techniques you can use to maximize the effectiveness of cardio; here are the ones I try to keep in mind at 6 a.m. Note: These tips are best suited for "leg-based" cardio--ellipticals, walking, stationary cycling, etc.
1. Keep It Tight
This seems like such a no-brainer, but because cardio is generally unpleasant and difficult for most people, this is the first area where they start to get lazy. SO many people just drape themselves on their machine of choice, hang on for dear life, and support as much of their bodyweight as possible with their upper-body to make it easier for their chubby little legs... Not only does this "coping technique" promote poor posture--which can contribute significantly to imbalances and instabilities (especially with the repetitive motions usually in play during cardio)--these techniques also reduce the efficacy of any resistance you are attempting to add. For example: A lot of people like to walk on inclined treadmills, but most of them also hang on--this doesn't just negate the benefits of using an incline, it actually makes it easier than if you were walking flat. If walking on an incline is more stress than you'd like to experience, reduce the incline, let go, and if that's too easy, increase your walking speed instead.
Pro tip: There's a difference between low perceived exertion and low exertion--make your body work more but feel less, not just work less. Keep an upright posture using your core and make your legs do the work they should be doing in the first place.
2. Keep Moving Forward
Here's another way people like to give themselves a break: pedaling in reverse, especially on elliptical machines. Let me first note that any arguments as to "using different muscle groups" are patently invalid--because the plane of movement does not change when the pedals are reversed, moving backwards is actually easier than forwards. Think of it this way: When you run or walk backwards, the circular "path" your feet follow tilts up and to the rear, but this doesn't happen on a machine--the "path" is still tilted up and forward, which makes going backwards a hell of a lot easier than it would be without the machine. I also advise against going backwards simply based on the fact that the unnatural angle of movement could easily contribute to knee and hip dysfunction.
Pro tip: If you feel like you need to catch your breath, simply reduce the resistance for a few minutes rather than pedaling backwards--you'll still get the break you want without completely screwing up your session--or your joints.
3. Don't Do Nothing
I'll admit it, I sneak a peek at the resistances other people are using, and I'm appalled by how often I see a big fat "1" on their screens. These people are usually also pedaling as fast as their legs can go--but with the lack of resistance, even the extra speed won't burn more fat. You're much better off adding some resistance, slowing down, and using your legs to actually push through the rotation. It's much easy for your body to just cruise on the momentum created by low resistance + fast pedaling, but it requires a lot more energy (read: fat) to push through the resistance and actually do the work necessary to carry your body "forward."
Pro tip: If you feel like your stride is pretty effortless once you "get going," consider slowing down so your body can actually feel the resistance, or if you prefer working at higher speeds, add resistance until you once again feel like you have to work to complete a revolution.
4. Try To Go Straight
Everything I have to say on this point can be summed up in a few words: If you're going to swing your arms, swing them straight back-and-forth--don't do any of that "cross-body" crap--your back and shoulders can thank me later.