Day 18: Chronic Cardio

Breakfast: Coffee
Lunch: Chicken salad; ½ avocado
Dinner: 300g burgers with tomatoes and pesto

Exercise: Sprints

I did about 10 minutes of sprints on a treadmill at lunch today.

When I do cardio I like to do HIIT – High Intensity Interval Training. There are a number of reasons that I prefer this to regular cardio (steady state jogs/cycles). Before I list them it’s important to discuss the differences between the two.

Chronic cardio is 30 mins+ of jogging/cycling/swimming at a constant pace. Your heart is usually operating at 60-80% of max beats per minute.

HIIT means that you are operating close to maximal effort for short bursts. That could be as much as 60 seconds on and 60 seconds off, or 8 seconds on 12 seconds off. You can sprint, use a stationary bike, lift weights, mix them all together, whatever. The point is that you are giving 100% in repeated bursts.

Cardio can be thought of as an ultra high repetition workout. High rep impacts leads to injuries, especially for people who have bad posture and weak mobility (i.e. everyone, especially desk monkeys). I regularly get injured when I run.

When you do a large volume of cardio you effectively send a message to your body that you will need a lot of energy. In response, your body stores more energy, i.e. body fat. You’ll also get more hungry after the workout in order to supply those calories.

While you may not burn as many calories during the workout, HIIT stimulates your body to burn more fat in the hour proceeding the workout. Moreover, since I burn less calories so my body doesn’t demand more energy i.e. I don’t get hungry and replace the calories I’ve burned with food.

Another thing I like about HIIT, is that it takes less time. You can do a decent workout in 10-20 mins.

I’m not going to run through all the pros and cons. You can read thisthis, and #3 in this from Poliquin’s website if you want to know more. I have, however, included a link from Mark Sisson, himself a former high level endurance athlete, on what he calls “chronic cardio”. It was a shock to me to learn that cardio could give you heart attacks. I always associated cardio with a healthy heart. But then, I also used to think that I needed carbohydrate for energy, and that eating too many calories would make me fat.

“Cardiac muscle doesn’t tear that way when over-worked, but it does enlarge and thicken with chronic overuse. In some – most – people the thickening is probably not life-threatening, but in some cases, as with dozens of world class athletes I have personally known, this thickening can cause all manner of issues later in life. Atrial fibrillation has become a mild epidemic in my generation of life-long aerobicizers; several of my friends have had pacemakers or defibrillators implanted before the age of 40 to head-off those sporadic life-threatening cardiac enervation problems. A few more friends have lost significant cardiac function and a few have died.”

I used to think that endurance races were the ultimate form of fitness. Now I realise that fitness means a lot more than endurance. To me it means being able to cope with whatever physical challenges come your way. In effect I think this means strength, speed, mobility, and stamina. I’ve needed to sprint for a bus, but never needed to run 20 miles.

I mean, look at this guy. What does he do if he needs to move some furniture, or carry luggage onto a train?

Bradley Wiggins


Seriously, who would you rather look like?

Sonny Bill