When Theory Meets Reality

According to Google, the most popular post I've ever written was published back in August 2015: Is Exercise a Stress Reliever or Stress Amplifier?  Clearly, every post I've published since has been an exercise in futility.

For those that don't understand my brand of self-deprecating humor, that is what I call a "joke."  Both my understanding of strength and conditioning, as well as my overall writing ability, have greatly increased since that post.  But I often forget that even though the concepts in that post aren't new to me - how certain types of exercise actually compound your stress levels - it's probably new to most people.



One such example came last week, when Bob Harper - yes, trainer Bob from The Biggest Loser - had a heart attack at age 51.  Mainstream media and the interwebz were shocked by the news.  I, however, was not.

Now, only Bob's doctors truly know what led to his heart attack.  But on the surface, he appeared to be the farthest thing from the stereotype of cardiovascular disease.  He looks like he's "in shape" (whatever that means these days), and he was named World's Sexiest Vegetarian in 2010. Of course, other factors may have raised his risk like a family history or other private issues.

But as evidence mounts that environmental factors are much more important than genetics, you can't help but notice the elephant in the room: stress.

Don't get me wrong, this post is not meant to blame the victim, only the opposite - to serve as a warning to all of us.  Why? Because I've seen the type before as well as the consequences. On the surface, Bob appears to be very Type A and "fight or flight dominant."  He's professed his love for Crossfit and their brand of high intensity work every workout.  And when you search the web for any of Bob's "low intensity" work, it's actually just another form of high intensity.  Our body produces the same reaction to stress regardless if it's mental of physical, so what Bob probably needs most is the ability to relax and to shape his workouts accordingly.

The irony, of course, is that those most in need of relaxing and being more "rest and digest" dominant are those that seem incapable or have no interest in doing it. To be blunt, those that love stress will seek out more stress.  In a way, it's a reminder of trashy reality TV and those individuals who claimed to "hate drama," when they absolutely love it.

So what can you do, especially if you're like Bob?  Here are a few answers:

1. Start Tracking Your Stress Levels Objectively

The two best - and cheapest - tools to use are resting heart rate and heart rate variability.  While I've written about both before, they begin to tell the story of how "fight or flight" or "rest and digest" you are.  For example, if your resting heart rate is above 60, you're going to be much more stressed and "fight or flight dominant."  If it's under 60 - or even under 50 - you're more rest and digest dominant and will tend to live longer than the majority.

Even overly manly man could use some low intensity work..

Even overly manly man could use some low intensity work..

But many different things can affect your heart rate, so the better option is using heart rate variability.  By measuring the time between your heart beats, you get a better sense of the balance of your autonomic nervous system.  When you inhale your "fight or flight" system kicks on and your heart rate speeds up, and when you exhale your "rest and digest" system kicks on and your heart slows down.  As counterintuitive as it seems, we actually want as much variability between our beats as we can get.  If our heart beats like a metronome, that shows we can't shake our stress or "fight or flight" dominance.

There are free apps out there, but I'm a big fan of BioForce HRV for those that would like to learn more.

You can also begin to track some other blood measures at your next physical - your standard cholesterol markers, hs-CRP (high sensitivity C-reactive protein), and homocysteine levels. This may seem excessive, but it's better to be proactive than reactive.

2. Place More of an Emphasis on Long, Slow Cardio

A few years ago I was a staunch advocate of the "move weights faster" movement.  For those that don't know, it can be explained by this saying: "But what do you do for cardio?  Lift weights faster." If only it were that simple.  

I've since changed my tone and am now a harsh critic.  Because once you gain a deeper understanding of how our heart adapts to both high and low intensity exercise, you realize the devil is in the details.



When you perform low intensity exercise - heart rate between 120-135 - you're allowing the maximal amount of blood into your heart.  This stretches our left ventricle and results in something called eccentric hypertrophy.  We experience an increase in stroke volume, the amount of blood our heart can pump out with each beat.  With a more efficient heart, our resting heart rate will tend to decrease, and you'll actually kick on your "rest and digest" system.

High intensity exercise - heart rate above 150 - has a different effect on our heart.  Instead of making our heart bigger, it forces concentric hypertrophy making the walls thicker.  The caveat is that our heart doesn't grow outward, it grows inward. Think about it: if your heart is constantly beating fast and all you do is high intensity, you're constantly trying to force blood out to get to the rest of your body.  You'll have a strong beat, but it's not going to be as efficient as larger heart might be.

The solution is obviously to have a bit of both, but to follow the 80/20 rule: 80% low intensity, 20% high intensity.  However, most people (including my younger self) have it completely flipped and that's where they run into trouble.  

The next time you're aiming for cardio with a run, walk, or a bike ride, try to honestly keep yourself at only 120 beats per minute.  For most, this will be a humbling experience.  But your cardiovascular system will thank you.