'Cardio' v Aerobic
Monday, January 30, 2012 at 9:12PM Following the post on aerobic training a few months ago a number of people have asked what the difference is between 'cardio' and aerobic training, so here I will aim to make a distinction between the two and clarify my position on them.
As the name suggests, 'cardio' is training for the heart; very simply, that will be achieved by raising your heart rate for an extended period of time. On the other hand 'aerobic' and 'anaerobic' relate more to how hard your muscles are working. Activity is considered aerobic when we can breathe in adequate oxygen for our energy demands to be met by the low-intensity aerobic system, one of three pathways our muscles use to generate energy. Activity which is performed at a higher intensity creates a situation where we can't breathe in sufficient oxygen to meet energy demands and the working muscles must rely on anaerobic methods of energy generation. Our anaerobic energy systems are relatively short-duration in nature whereas aerobic energy production can be maintained for very long periods of time. That doesn't make it better, just different! Both aerobic and anaerobic training will elevate the heart rate, with the latter raising it further; both therefore can be considered 'cardio'. Because treadmills, rowers, bikes, cross trainers and steppers are universally known as 'cardio machines' it is hardly surprising that we have a situation where the majority of people believe that these machines are the only way to exercise their heart in a gym, with swimming, running, cycling and any active sports fulfilling the same role outwith the gym. Weight training is considered to serve a completely different purpose by most. But does it elevate your heart rate? You better believe it! Measure your heart rate after a set of squats and you may be surprised at just how high it is! Even exercises which don't involve as much muscle mass as the squat will create a response similar to that experienced during aerobic exercise. Structure your programme appropriately, for example using supersets or a circuit-style approach, and your heart will receive a training effect just as effective as that achieved with traditional cardio. Really, anything which raises your heart rate to an appropriate level for a reasonable length of time can be considered cardio.
So the advice to do cardio for health reasons is sound, but you need to separate the terms 'cardio' and 'aerobic' as they are not the same thing. As I've discussed before, aerobic training can actually be detrimental to your health because of increased oxidative stress, inflammation, depressed immune function and elevated cortisol levels. Weight training and anaerobic training, e.g. sprint intervals and strongman training, provide the 'cardio' benefits without the downsides, still improve your aerobic fitness and are also more effective when it comes to fat loss. So, unless you particularly enjoy aerobic exercise, I really can't see the point of doing aerobic work when you can get your cardio from much more effective forms of training!
Finally, it should be noted that most of the time our muscles are fuelled by aerobic metabolism, this is not something which only happens during exercise. Likewise, our heart rate fluctuates up and down over the course of the day depending on what we are doing. Activity must therefore reach a certain threshold level before it can be considered 'training' so please don't believe that a hectic day at work or at home running around after the kids is a substitute for exercise! This is why it would also be incorrect to claim that classes such as Zumba or Pilates are forms of aerobic exercise. They may be benficial for other reasons, but they are certainly not challenging enough to be considered as effective aerobic or cardio training methods.
Reader Comments (2)
Quite impressed by this blog, very short and precise! Like it, i also like when you have a rant though and you go off in tangents....
Thanks Norma. I'll ensure my next one is more rambling!