Cardio: What to Do?

It is important to understand that cardio refers to any exercise in which the heart and lungs are involved. This could be jogging, running, sprinting, swimming, circuit training etc.  Quite simply - if you are elevating your heart rate and respiration rate, you are doing some form of cardiovascular work. 

Aerobic training refers to a state in which the cardiovascular work is performed. Aerobic literally means 'with oxygen'. It is a relatively low intensity state of exercise that can be maintained almost indefinitely (as long as oxygen is being supplied to the working muscles, in the required amounts - the exercise can be continued. This is aerobic training. 

All aerobic training is cardiovascular training. Not all cardiovascular training is aerobic. Hopefully that makes sense.

~Alwyn Cosgrove

My aim in posting the above quote by Cosgrove is to clear up semantics, as it seems to me that whenever I'm discussing "cardio" with someone, we are each thinking of two completely different things.  Most people, when hearing the word "cardio," immediately picture a long, steady state jog.

There's a difference between cardio (anything that ELEVATES your heart rate), and aerobic (a state of SUSTAINED heart rate, in which your cells still have oxygen to utilize for function). 

Heck, sitting and watching and TV is aerobic!  Walking around and eating in your kitchen is aerobic.  I hope this puts a few things into perspective as, unfortunately, not many people are even aware of what "aerobic" really means.   

O.k., now that (I hope) semantics are cleared up, let's continue.  With regards to cardiovascular training, it seems that people are frequently on one of two sides of the spectrum:

1. The "I can't stop" crowd.  The world will explode if they don't go on a run that week.  Or Earth will cease to revolve around the sun if they don't go to the track and perform a 400 meter sprint and follow it up with 15 power cleans, 20 deadlifts, and 25 burpees.  And and then do it again.  10 more times. 
2. The "I hate cardio" crowd.  Be it laziness, lack of priority, or fear of losing weight/muscle (for the macho men in the crowd), they never do it. 

As with most answers in the strength and conditioning realm, the answer lies somewhere in the middle.  Don't get me wrong: I see no problem with periodically pushing yourself to "see what you're made of", and I also think there is a time/place to omit (intense) cardio for a bit, in the case of someone trying to gain weight.  

What type of cardio to do? (note: the practical portion is at the bottom of this page, if you're not interested in the "why")

When it comes to fat loss and conditioning, I prefer to keep people I coach out of a particular Heart Rate Zone: 70-85% maximum heart rate.  This is the very same heart rate zone people often find themselves in when they go off on a long, slow jog to get their "cardio" in for the day.

Throughout myriad experiments - both in labs and in real-world scenarios - the 70-85% intensity level has been shown to interfere with gains in maximal strength and power (via fiber type shift from fast twitch to slow twitch).  When I took a Neuromuscular Performance course in college, we studied the cell-signaling pathways that take place when one undergoes endurance training.  These signaling pathways actually inhibit (to a degree) the very same enzymes, cell signals, transcription factors, etc. that drive the strength and power output adaptations that take place when one undergoes a resistance training program.  There are always competing demands taking place within your body when various stimuli are applied via particular training sessions.  The trick is ensuring one doesn't completely override the other. 

My point is that a well-rounded program - especially for those seeking fat loss - needs to include both a resistance training and a cardiovascular component (among other things) in the program.

The resistance training portion will maintain and build lean body mass (muscle tissue), which will elevate your resting metabolic rate and help you look better with your clothes off.

The cardiovascular component of the training program is important as well for various reasons: acute elevation in cardiac output (contributing to long-term elevation in capillary density of the type I fibers - a good thing), improved insulin sensitivity, lower blood pressure levels, better glycemic control, and decreased body fat, to name a few. 

I may be losing most of you at this point, so what's the bottom line?  One needs to include both a resistance training and a cardiovascular program in his or her program, but the problem is that most people's "cardio" plans interfere with the positive adaptations that can take place from their weight training sessions.

How does one avoid this?

1. Keep your "cardio" in the 60-70% HRmax range (think: a brisk walk during which you can string a sentence together without losing your breath, but you can't string multiple sentences together).  I think going for a walk is extremely underrated, and is beneficial for almost anyone. 
2. Keep your "cardio" above 90% HRmax (think: High-Intensity Interval Training, or HIIT). 

Here are a few exercise modalities I recommend to meet the above criteria.  By no means a conclusive list, but something I hope can get you started:

1. Sled pushing/dragging is the clear winner, in my opinion.  Very low stress on the joints, and it's easy to recover from due to minimal eccentric loading on the muscles.  The important part is to avoid turning the sled session into a vomit fest (it's easy to do, if you've never pushed a sled before).  Ben Bruno just wrote an awesome post on sled dragging, so I won't elaborate much.  I highly encourage you to check it out HERE. 
2. Walk.  Again, I feel it's highly underrated and equally good for the mind as it is for the body. 
3. A light circuit of bodyweight exercises, mobility drills, and weighted exercises performed with no more than 30-40% of your 1RM.  The goal here will simply be to enhance blood flow to damaged tissue and keep your body fresh.
4. Jump Rope
5. HIIT.  Preferably on an Airdyne bike or something else low impact (even an elliptical if necessary). 
6. A high intensity body weight circuit such as the one I posted about yesterday (you can see it below).  This is a clear example of working in the 90+% HRmax range.  I don't recommend doing this often though, especially if your primary training goal is to gain strength and power.
7. Jog. 

To see which options you should choose depending on your goals/needs, see Part 2!

That's it for today.  Hopefully it cleared some of the cardio confusion out there!