Starting Over in Cardio

As I explained in the previous post Searching For The Cardio Code, after a very long hiatus, I’m ready to reintroduce cardio training to my fitness plan.

Some would argue that my long urban hikes or my 10,000 steps a day would qualify as cardio, but I am doubtful that my heart rate stays in that (180 – your age) range for an extended period. Seattle and San Francisco have hills and when I hike the streets, my heart rate may jump up enough to qualify as cardio, but only for a few minutes at a time. Also, as I mentioned in a previous post, years of doing SuperSlow HIT with exercises such as the leg press actually keeps my heart rate lower during the hill portion of these hikes.

Injury and Pain are a Concern

The reason I stopped running shortly after college was a pain in my left upper hip. Think of the spot between your belt and pocket. I never figured that pain out and it only went away when I stopped running. Yesterday, after 20 years, I got reacquainted with a mild version of that same pain after just 20 minutes on an elliptical trainer.

Even though my knees are much better than that were in April, they aren’t 100% and I don’t know if they ever will be. The left one still feels spongy when I try to run across a street. Some people say running can protect and strengthen the knees and others say running hurts the knees. I suspect it is a survivorship bias thing and I may be one of the people that running is not good for. But I’d love to be proven wrong, however, I do fear reinjuring my knee. Considering the years I’ve dealt with this problem, I’d rather err on the side of caution.

Cardio Ideas

Here are some ideas and my initial thoughts. Correct me where I get things wrong.


Not an option at this time, maybe never. See above for explanation.


I would never bike outside in Seattle. I would consider smoking to be a safer activity. I do have access to both types of stationary bikes in the gym. Both bore the hell out of me. I have been doing 5-minutes a few times a week for knee rehab. I’m watching the clock the entire time. My heart rate never gets into the cardio zone and my knee still doesn’t feel 100% comfortable with the movement.

Endless Rope Machine

Unfortunately, the 2 gyms I have access to right now do not have this glorious machine. This would have been a good option for shorter cardio sessions.

Rowing Machine

Dr. Jay from the Cardio Code loves the rowing machine. People I respect in fitness either love or hate this machine for injury risk. I honestly don’t know what to think. It is boring too.


Probably better than running, but not by much. I might experiment with power walking up an incline. If my knees are stable and my heart rate gets high enough, it is a candidate.

Elliptical Machine

Even though I got hip pain yesterday, this may have potential. My knees were happy. Too soon to tell.


My new gym has a pool and I’m a decent swimmer, so this has potential. The only downside is depending on how crowded the gym is, my access to a pool lane will be less than certain. This would be a good backup choice.

Aerobic Dance

Never going to happen. Next.


I love hiking, but I would need to travel to get to a trail where there was enough elevation to keep my heart rate up for 20+ minutes. For normal people that don’t know the power of HIT, there are hikes close by that would work for them, but not for me.


I do have access to a very long set of outdoor stairs near my house. I’ll add them to the list.

Weighted Vest

Perhaps a Weighted Vest is an ideal way to get the heart rate up without increasing the speed of the cardio? Walking with a weighted vest is likely going to be better on my knees than running without one. Does that sound correct? It would need to be cheap. I see some on eBay. Wonder how many pounds I would need?

Your Thoughts

If you were me and my knees, what would you do for cardio? I will ease into cardio on both time and times per week. My motivation is to expand my fitness. I won’t continue if I’m in pain. If I can listen to podcasts that is a huge plus.


Photo by Marcus Ng

Searching For The Cardio Code

One of my fitness mentors is Chris Highcock from Conditioning Research and author of Hillfit. He always seems to be a year or two ahead of me when it comes to fitness interests and knowledge.

In a comment recently, he referenced a book called The Cardio Code that makes the case for why the science is clear that cardio is necessary for heart health and that lifting weights or even lifting weights in an interval setting is not enough. If anyone else had posted the link, I would have dismissed it and moved on, but it was Chris, so I fired up Bing and did a search.

The Cardio Code was released in 2014, but unfortunately only as an iBook on Apple iTunes. No paper. No Kindle. I dusted off my version 1 of the iPad only to discover I can’t update to the latest iOS version in order to read the book. And since I use Windows and not Mac, I can’t read the book on my laptop. I really do not want to have to read a 270-page technical book on my iPhone.

Now there may be a way to buy the book and convert it to a Kindle-friendly format, but every time I’ve done that in the past, the formatting has been a disaster.

Why wouldn’t the author put the book up on Amazon? There are services to handle both the conversion to Kindle and print-on-demand.

I discovered the author’s website, which to be kind is “a piece of crap”. More embarrassing than McGuff’s Body By Science site before the “Chinese hackers” got to it. 🙄 Sorry, I’m a little opinionated on this topic. See The Digital Graveyard of My Health and Fitness Mentors for details.

I located a January 2017 podcast interview with Dr. Kenneth Jay on Leo Training. You can hear that here. The cardio portion of the interview starts around 19 minutes. Although his publishing strategy and website are terrible, his arguments impressed me.

My bias against cardio took a serious blow. Now perhaps someone in the HIT community far smarter than me can find flaws or disagreements with Dr. Jay, but I couldn’t. I still want to read the book or something to better understand this topic, but I’m not buying a new iPad to make that happen.

Not giving up, I went to the Wayback Machine and found an earlier version of the Cardio Code website. A much better version too!

Some highlights from this page:

  • Cardio is defined as exercise or training to make your heart work better.
  • The goal is to improve the pumping- and blood delivery capacity of the heart to the working muscles.
  • The best stimulus to your cardiovascular system is when is when you DO NOT limit blood flow back to the heart.

Why not just lift weights faster?

The problem arises with the muscular tension used to lift the weight. Because blood delivery to the working muscles depends heavily on perfusion of the muscle (meaning: can the blood actually get to the muscles that need it?) the oxygen rich blood has a hard time getting into the contracting muscle as it (the muscle, that is) will squeeze the blood vessels shut. The vessels may not close completely (that depends on duration and intensity of the contraction) but the blood will have a harder time getting to where it is needed. This is of course a major problem, which will increase heart rate in an attempt to force blood into the muscles. Unfortunately, the net result is only a large increase in blood pressure and a limited return of blood to the heart.

The rest of the blog post discusses VO2Max, intensity, and sports variations.

Right or Wrong? Undervalued or Overvalued?

As a once hardcode cardio skeptic, do I think Dr. Jay is correct? Likely, but for me, that is the wrong question to ask. He is smarter than me as are some of my fellow cardio critics. The way I am approaching this question is as an investor.

For at least a decade, I have heavily invested in the cardio is crap exercise portfolio. I achieved tremendous gains using HIT and walking, but it appears to be time to rebalance my portfolio. Cardio is undervalued to me at this time. It is worth pursuing.

I’d still like to read the book, but that may not be possible. In the meantime, I will ease into some cardio. What type? That will be the topic of my next post.

me on a bike

Time to dust off my old bike? 🤣

Understanding My Bias Against Cardio

One of my favorite podcasts is Masters In Business from Bloomberg by Barry Ritholtz. The show is a collection of interviews with some of the brightest and most successful people in finance. (side note: Ritholtz actually left a comment on this blog way back in 2006)

One of the lessons I’ve learned from the show is about discovering your own biases when it comes to investing. Not just cheerleading the times you were right, but digging into the reasons on those time when you were wrong. There are learning opportunities available when you get something wrong, but you need to face them.

Which brings me to cardio.

This blog has been dismissive of the role of cardio training for a decade. My view on the topic has been it is completely unnecessary. Just build your muscles and go for walks. The strength gains you make in the gym will make any form of cardiovascular training easier. This is true, but that isn’t the full picture.

My belief that cardio isn’t needed for health just got rattled really hard this week. That will be a topic that I will explore in more detail later, but first I need to examine how I became so certain on something that appears to be wrong.

Here are the reasons I came up with.

#1 Tribal

During college and shortly afterward, I was a runner. I completed two marathons (both under 4 hours) and a few triathlons. I loved running. I loved cardio. But I could never go long periods without being in pain or injured. I’d recover and then work to get back in shape. It felt like I wasn’t progressing.

I discovered lifting weights and made those initial gains and I was hooked. Now I was a lifter. Not a runner. My tribe has muscles and hates running. I didn’t want to go back to being a stick-boy.

Instead of using a more moderate approach to running to compliment weight training, I ditched it. I was not only more muscular, but I was also leaner from lifting than running, which validated my choice.

#2 Fat Loss and Appetite

In the 2012 post How Exercise Indirectly Kept Me Fatter, I discussed how I never got the fat loss benefits from cardio.

Although in the short term, it appeared at times that exercise helped me get leaner when looked at over a longer time frame it didn’t. Exercise increased my appetite and as long as I kept exercising my weight was in check. However, whenever volume increased past my body’s ability to recover, I was sidelined. During the periods of being sidelined, my appetite always exceeded activity and fat gain occurred.

I still believe this to be true, but maybe had I approached cardio work in a less extreme manner and solved for winter those fluctuations in appetite would have been smaller.

Today, I know tricks to reduce appetite without experiencing hunger (higher protein and higher volume foods such as the potato). Back then I was less skilled in the art of controlling calories.

#3 Paleo

By the time Paleo hit, I was ready to accept their narrative that Grok would never be so foolish as to run around wasting energy doing cardio. Grok would use strength and quick movements to survive.

Good enough for Grok, good enough for me.

I never dug into the truth on what Grok actually did – even if we know – because I liked the story. It told me what I wanted to hear. Plus, eating like Grok was leaning me out, so it must be true.

During this time period, every time a marathoner would drop dead from a heart attack, those news items would be shared, thus shaping my view that cardio was not only unnecessary and ineffective but potentially dangerous

#4 Accepted by HIT community

In 2011, I posted The Myth of Cardiovascular Training. Because of that one blog post, I was invited by Greg Anderson to do a HIT workout at his Seattle gym. Greg Anderson was the guy that trained Dr. Doug McGuff, author of Body by Science. I become a HIT convert and disciple. He also wrote a similar more detailed article on the same topic years before.

The view that cardio is a myth is popular in the HIT community. They loved my HIT posts and I loved their anti-cardio message.

I was using HIT exercises such as a SuperSlow Leg Press very effectively. I still recall walking up a long steep hill with a friend that did hours of Zumba every week for many years. She was winded and I wasn’t. And I did zero cardio and was proud of the fact that I never broke a sweat exercising. That was my confirmation that cardio was nonsense.

Now I can see that I made the same error the cardio-junkies made, just the flipside. Cardio warriors train their heart to be stronger but do little to strengthen the muscles to support their heart. Meanwhile, I was building my muscles to take the load off my heart, but doing nothing to directly target the cardiovascular system.

Common Thread

The common thread on how my view of cardio was formed and validated is that I had a narrow and incomplete view of what health is. I also didn’t challenge my assumptions, which is something I did frequently with nutrition. I

If I get a knee pain running, that doesn’t mean cardio is bad. That form of cardio might be bad for that knee, but not for the heart. Leanness and strength are important components of health, but having a tighter midsection and more muscles are not a free pass to avoiding cardiovascular training.

It all comes down to one question. Does cardiovascular training provide unique health benefits that can not be achieved except through cardiovascular training? I used to be certain the answer was no. Now that belief has been rattled. I’ll share what I discovered in the next post.


Photo by Bruno Nascimento