It seems to be one way or the other with most fitness enthusiasts:
You either love cardio so much that you neglect strength training, or you despise it and angrily punch your time card at 20 minutes, twice a week.
Depending on your health and fitness goals, varying degrees of cardio endurance and training are necessary for optimal health. Regardless of whether you're training for a marathon or simply making sure that your workout is well-rounded, most of us do some sort of cardio training.
But most of us could get so much more out of it!
For the sake of simplicity, we're going to use running as the activity for this example. It's the most common, measurable, and accessible form of cardio training that I can think of; it's also where a lot can go wrong. However, many of these tips can be applied to other forms of cardio. If you have questions about this, feel free to ask me.
-Do some ab work in your warm up! Waking up your ab muscles, even just for 5-10 minutes, will help you maintaining better form throughout your workout. You'll reduce the impact overall from your stride, and keeping your abs a bit engaged while running can help protect your spine from the compression it receives whenever your foot lands on the ground. Plus, if you keep your abs tighter during the run, that means that you're ALSO getting more from the ab routine you did: win-win! I recommend to do at least 3 of your favorite abdominal exercises, and make sure you definitely come into forward spine flexion (as in a half roll-up or "crunch"-type movement, for example), twisting (Oblique "crunches" or sitting spine twist, for example), and stabilized neutral spine (as in a plank). In an ideal world, you would also do some sort of lateral flexion (side bending), and spine extension supported by the abs (spine arching back).
-Make sure your spine is not stiff. This can be as simple as lying on your back for a spine twist, or you can do hip-rolls (a Pilates movement - feel free to check out YouTube).
-If you carry lots of tension in your hip flexors and/or IT band** (and many people do), getting on the roller for a bit prior to running can help prevent over-gripping these muscles. Don't over-do it, though - only roll every other day MAX, no more than 3 times a week is ideal. Prior to a workout, all you need to do is roll over the area 8-10 times, and avoid putting weight directly on a protruding bone (such as the greater trochanter, that bulb-y bone on the side of the hip) or a joint (such as the knee). Tight hip flexors can lead to lower-back compression and pain during a run, and tension in the IT band can tug the knee slightly out of alignment which can lead to knee pain very quickly.
-DO NOT STRETCH PRIOR TO CARDIO. The one exception is if you have tight calves - this muscle group can be gently stretched before and after. Do not stretch your quads or hamstrings unless instructed by a medical professional (like a Physical Therapist) to do so as it can make these muscles more prone to injury during your workout.
-If you're prone to hamstring injuries or pain, do a few reps of a simple exercise to "wake them up" prior to your workout. You might do a bit of a wall-sit, or a few squats, or lie on your belly and do some leg lifts to get the glutes and hamstrings ready to fire.
During the Workout
-Keep your abs gently braced throughout. I think of it as 20-30% of the engagement you experience during one of your tough ab routines.
-An activity like running puts about 4x your body weight into your joints every time your foot lands. Do a mental check of your hip-to-knee-to-ankle alignment every now and then throughout your workout. Your knees should be landing under your hip bones, your kneecaps should be aimed past your second/third toes, and your ankles should be neutral, not rolling in or out or "flopping" while in space.
-Try to land lightly on your feel rather than "pounding down." Keeping your abs braced helps with this, and I find that aiming to keep my head level also helps my trajectory moving more forward rather than downward.
-If your heart rate gets too high, this stresses the body unnecessarily. Breathing in through your nose and out through your mouth can help lower heart rate. If needed, slow your pace slightly and try to make your exhales take twice as long as your inhales to keep your heart rate under control. Your ideal heart rate depends on your goals, however, so please seek the advice of a well-trained professional if you're not sure what your range should be.
-Take the time to properly slow- and cool-down. Slow your pace, and removing motion from your arms (I just place my hands on my hips or hold the rails) while bringing attention to your breath (see above) are effective ways to slow your heart rate.
-Do not drop your head below your heart until your heart rate has dropped significantly. To do so puts unnecessary strain on the heart that can be dangerous for some people.
-Hydrating with elecrolytes is optimal, but try to avoid refined-sugar and chemical-filled drinks like gatorade. www.ThriveForward.com provides some free recipes for excellent health-promoting hydration tonics.
-THIS IS WHEN YOU STRETCH. If you choose to do a more intense stretch conditioning session, then get yourself dried off and comfortable first. If you are really only focusing on the cardio, then just a handful of stretches can make a huge difference in your recovery. Gently target: calves (again), hamstrings, quads/hip flexors, piriformis.
-Take care of your back. Whether it's a few more hip rolls or a lying spine twist (like in your pre-workout), or even simply lying on your back and hugging your knees toward your armpits, take a moment to create space in your lower back to alleviate the compression and relax the tension-carrying muscles above the pelvis.
-Go grab a shower, 'cause you smell! ;-)
I hope you've picked up some helpful tips to get a lot more out of your cardio!
**Disclaimer on the IT band: some people do not have a tight IT band and mis-diagnose themselves as such. Under-trained personal trainers often mis-diagnose this, as well. Instead, one may have a weak gluteus medius, and this may be what is causing the knee issues. It can be damaging to do too much rolling on the IT band if it's NOT carrying tension, so please seek the advice of a Physical Therapist or a VERY well-trained fitness pro who truly understands anatomy and how to assess proper muscle-firing if you are not certain that your IT band is the issue.