August 7, 2012: Day 6 of 30

Today was a better day at work.  I had several meetings which made the day go by faster, which is a blessing.  As each day goes by my spirits lift.  The guilt about resigning from this position "before the job is done" is gone.  I know that I made the right choice and I am looking forward to starting my new job on the 22nd.

I am very grateful for this 30 day plan.  The extra discipline and rigor of the plan is exactly what I need as the world around me shifts by 180 degrees.  Instead of eating my way through this, I am focusing on my plan and I am determined to follow it to a T.  Ruth's advice to read from "Younger Next Year" every day and blog about it was truly inspired.  Not only is reading the book reminding me of all of the reasons I need to stick with my plan, but writing about what I've read is making it stick.  This extra focus on why exercising every day is the right thing for me to do makes doing it more pleasant.  I guess, in a way, it's more fun to exercise when I am reminded of all of the wonderful things it is doing for my body.  It feels like less of a chore and more of a gift.

The following is a recap of day 6:

8/6/2012: Day 6 of 30
Morning weight: 182.0
Today's calorie count: 1455
Morning exercise: Day Off
Evening exercise: 30 minute walk/jog (7 minute walk, 15 minute jog, 8 minute walk)
Alcohol consumption: None
Younger Next Year pages read: 16
Notes from book:  (Quotes and very near quotes in italics)

These 16 pages were the remainder of the chapter that I started talking about yesterday.  My last post talked about mitochondria and the fact that they can burn either fat or glucose, depending on the type of exercise you do. 

Harry then talks about the two basic types of aerobic exercise; low intensity exercise that burns fat and high intensity exercise that burns glucose.  These two types of exercise are important because they mimic two critical biological functions of humans, foraging and hunting.  In the good old days, those two activities consumed a very large part of our day and each one called for very different body and brain functions:  highly coordinated and specific patterns of thought, mood, energy, digestion, immune function and muscle metabolism.  Our bodies and brains geared themselves to our daily environments based largely on our exercise patterns, and that's still how it works today.

Because these two types of aerobic exercise, low intensity and high intensity, trigger very different behaviors in your body and your brain, it is very important to get both types in your weekly routine.  Low intensity aerobic exercise means exercising at a pace that will cause you to reach about 65 percent of your maximum heart rate.  You can look up maximum heart rates on the Internet, but it is important to know that the older you get the lower your maximum heart rate is.  For a 50 year old, 65 percent of your maximum heart rate is 110 beats per minute.  For most of us, including me, a brisk walk will get us to 65 percent of our maximum heart rate.  Harry calls this our first gear. 

Beyond 65% of our maximum heart rate we start burning glucose in addition to fat.  Because burning glucose requires more oxygen, we must get more blood to our muscles, so our heart rate goes up.  Any heart rate above 65% moves us into 2nd gear.  At about 80% of our maximum heart rate the chemicals can't move between blood and muscle, or within the muscle, fast enough to keep up with the demand.  For a 50 year old, 80% of maximum heart rate is 136 beats per minute.  Above 80% of max, your muscles become starved with oxygen and the glucose can't burn all the way down to carbon dioxide.  Instead, lactose, which is incompletely burned sugar, accumulates in your muscles and shuts them down.  Chris and Harry recommend wearing a heart rate monitor so that you can tell when you are in 1st gear, 2nd gear, and above 80% of your max heart rate.  When I started wearing a heart rate monitor last summer I realized why I hated exercising so much and why it hurt so badly, I was working out too hard.  I was consistently jogging at over 80% of my maximum heart rate and I was also consistently in pain and exhausted.  I encourage you to buy that heart rate monitor and use it!

Even though it feels like a brisk walk may be a waste of time on the exercise front, it's not.  Exercising at 65% of max is the metabolic zone where your body and brain heal and grow.  It's the zone where steady, low-grade C-10 drives the slow, consistent growth of infrastructure:  blood vessels and mitochondria in your muscles; repair and health throughout your body.  Harder exercise will make you more fit, but you gain endurance and get healthier with prolonged light exercise.  You may start your program by doing this light aerobic exercise 6 days a week, but eventually, once your foundation is built, you will do light aerobic exercise twice a week and something else the other four.

Once that fountation is built Harry recommends working up to four hard aerobic days a week. The shift into 2nd gear changes your metabolism because the hard exercise is the signal to your body that you have begun to hunt.  Here's how it works.  Animals in nature never move out of their low aerobic zone unless they're hunting, being hunted or playing (rehearsal for the first two).  Glucose is a powerful but expensive fuel.  Your body knows that you would never move fast enough to burn glucose while foraging.  That would be a waste of energy, which is to say that it is biologically insane.  If you're burning glucose, you must be hunting, which triggers a major metabolic shift that affects your muscles, brain, gut, immune system, kidneys, liver, heart and lungs.

The long slow exercise prepares you for the heavy exercise.  It improves your body's capacity so that it could perform for you at these higher levels.  Adding the hard aerobics makes your body faster and more powerful.  It drives your body to store more glucose in the muscles, making them ready for sustained, hard exercise.  Hard aerobics, working up a good sweat, is our favorite exercise rhythm because hunting brings out our youngest and best biology:  strong, fast, energetic and optimistic all day long.  That's why you should do low aerobic exercise a couple days a week, to build your base, and then go out and play hard on the high-aerobic fields the other days.  Tell your body it's springtime several days a week.

Re-reading this chapter makes me realize why I enjoy hiking and biking so much.  Those are activities that keep me at about 65% of my target heart rate.  When I am hiking or riding my bike, I am improving my infrastructure.  I had fallen into the trap of thinking a brisk walk or a bike ride was not hard enough exercise.  I had forgetten this important lesson of the book, to exercise at the light aerobic level twice a week.  I guess that is why it felt so good to get back on Blacky on Sunday.  It was exactly what the doctor ordered!!