Performing High Intensity Training in a circuit fashion is a satisfactory cardiovascular workout for general health and wellness. The heart and lungs do not know what you are doing, they only work in terms of demands. However, this approach will not adequately prepare you for certain demands. The cardio needs of a mixed martial arts fighter, for instance, will not be met solely by lifting weights in a circuit fashion. As Robb Wolf spoke of on his podcast (19:19), depending on your sport or your efficiency in practicing your sport, you can sometimes gain all the metabolic conditioning needed just from the practice of your sport alone. But occasionally, supplemental work is needed.
In this instance, I believe a high intensity approach is also appropriate. Brief, but intense, anaerobic conditioning sessions provide excellent benefits while minimizing muscle/strength loss and not impeding your gains in the weight room. Just like in the weight room, progress is key. The same MetCon workout that ruined you in January shouldn’t continue to ruin you in February…progress and improvement must be evident.
Some sample workouts I like to cycle through:
I also enjoy the following sprint workout inspired by Keith Norris:
Bring two markers (cones, beanbags, etc) to a sprint-worthy stretch of ground. Sprint all out at top speed for 6 seconds, and drop your first marker wherever you end up. Rest an appropriate amount of time (30-45 seconds for conditioning, longer if you’re working on max sprint speed), then run another 6 second sprint. You should beat your previous distance, drop the second marker at that point. Always aim to beat your previous sprint, leaving the other marker where you end up to constantly record your furthest distance. When you miss your mark by roughly 10% or so, pull the plug on the workout. The ensures you don’t impact your recovery ability to such an extent that you can’t recover from it adequately before your next session. I love this approach because your body provides you the feedback on when to stop working. It also provides built in intensity-increases. You are sprinting all out, 10/10. As your capacity improves, that 10/10 will be greater than the previous 10/10. As long as you’re going all out, you’ll always be giving yourself a good workout. I wouldn’t sprint more often than once a week or so, to ensure you don’t beat yourself into the ground, or impact your gym efforts.
What about cardio for fat loss?
I don’t believe cardio makes sense for fat loss. Marathon cardio sessions are tough to recover from, contribute to muscle wasting, and raise cortisol levels. The calories burned in these sessions can be completely wiped out so easily by a cheat meal. You can’t possibly outwork a bad diet. However, concentrating on keeping your diet on track while maintaining/gaining lean muscle mass through intelligent weight training (thereby improving insulin sensitivity) provides an excellent environment for fat burning. When you have your diet and weight lifting dialed in, the fat loss will come, and it doesn’t require the hours in the gym that tons of cardio requires.