Disclaimer Reminder: Just a reminder folks, I am not a doctor, nor do I have any expertise in any subjects regarding to health. Before you take on ANY health program, consult your doctor!
Chronic Cardio and High Intensity Interval Training
Ahh cardio. I remember back in the day, thinking that if I wanted to lose weight, I needed to do some serious cardio. Two hours a day of heavy running at least, pushing your body to the absolute limit! Very silly in retrospect. I still cringe at people clocking 1.5hrs+ on the treadmills in the gym in an attempt to lose weight. I would love to reach out to the,m but I don’t want to be “that guy”. I try to lead by example and when people ask me what my cardio routine is, I hope they follow.
What is chronic cardio?
Chronic cardio is essentially any long length, high intensity cardio session. I am talking 80%+ heart rate for extended periods of time. It is this cardio, which stresses your body as well as depleting your glycogen stores. At 80% heartrate you are performing anaerobic exercise, which is very inefficient in regards to converting glucose into energy so your glycogen stores are rapidly depleted. Your body (muscles and liver) can only store about 600g of glycogen at any one time, and this can be depleted in only about 1.5-2hrs. If you do this on a daily basis you need to consume 600g of carbohydrates a day to replete your glycogen stores. That is a ridiculous amount of sugar and insulin to be exposing your body to!
Why is chronic cardio bad?
Well aside from the massive sugar and insulin rush which we know causes a whole host of issues on the human body, chronic cardio puts un-needed stress on your heart, increases cortisol (stress hormone), oxidation damage, weakens the immune system and, get ready for it, REDUCES fat metabolism.
So what cardio should I do?
To answer this we will look at our paleo ancestors (go figure!). Grok was nomadic so he was constantly on the move. Every now and then however, when some sabre tooth tiger was after him, he would need to sprint his heart out to get away. With these two considerations we can design our cardio exercise plan.
To emulate those long walks and constant movement, a good 30 minute a day session of low intensity (60-70% of max heartrate) is all that is required. Eventually you should barley break a sweat with this type of exercise. Now, to emulate those times where we had to sprint and get away, we include a couple times per week a session of high intensity cardio for no more than 15 minutes. Some High Intensity Interval Training (HIIT) is perfect for this.
High Intensity Interval Training? What’s that?
High intensity Interval Training, as the name suggests, consists of short bursts of high intensity exercise. Some examples are:
- 60/30 (or 90/30) Split. Where you go 60 seconds of low intensity followed by 30 seconds of all our going crazy for a total of 15 minutes. This can be done on a stationary bike, on the running track, wherever you like.
- The Famous Tabata Protocol
Whatever the case, the basic premise is this. Go crazy for a short period, then relax. Do this 1-2 times a week, with 30 minutes of low intensity every day, and the fat will melt off (amongst other great health benefits!)
How it worked for yours truly.
I never could run long distance. In fact I hated it. After going paleo, the longest cardio session I ever did was 45 minutes long .That was on a stationary bike at ultra-low intensity whilst reading a book. A few months ago I read about a local 12 km fun run. I decided to enter. Without ever training for distance, or ever running for any extended period of time, I did it nonstop in 1hr 30 minutes. Not a fast time by any means, but pretty good for someone who 6 months earlier couldn’t run 200 meters without panting and getting dizzy.
At the end of the day, that was what I always wanted.
Some studies and further reading for all you nerds out there:
- Enhancement of fat metabolism by repeated bouts of moderate endurance exercise
- High-Intensity Interval Training Is Time-Efficient and Effective, Study Suggests
- Interval Training Burns More Fat, Increases Fitness, Study Finds
- Effect of low-intensity aerobic exercise on insulin-like growth factor-I and insulin-like growth factor-binding proteins in healthy men.