This is that long, slowish run that we use to teach our bodies to use fat for energy over a long period of time.
In simple terms “time on our feet” is more important than pace. As a matter of fact your goal is to keep your pace and heart rate at a very moderate level. At the end of this post, I can share some of the science for those interested.
Run easy today!
HOME FIELD ADVANTAGE- we take the opportunity to run over the course that most of us will compete on in January.
13 Miles or less - we are using the actual Louisiana Half Marathon course. There are numerous options to shorten it.
20-22 Miles - the 20 mile option is perfect for most of you. BUT…if you are experienced and are looking for a competitive time you may want to run 22. OR if 22 gives you more confidence that you can finish well.
20 Miles using Louisiana Marathon Course
Hydration will be at Baton Rouge Beach at the usual place.
20 Milers may want to put stuff out on the back half.
The science: “Aerobic running is easy running at below 80% of your maximum heart rate. Running in this aerobic zone maximizes an athlete’s ability to burn fat as a fuel source. It’s running at the kind of pace where you think you could go forever. In the aerobic zone your body uses oxygen to power the muscles, fuelling them with both glycogen (carbohydrate stored in the muscles) and fat (its preferred energy source). With this power cocktail of fuel, your muscles can keep going. And going. And going.
Anaerobic training is what happens when you kick the intensity up a few gears. The ASCM defines it as “intense physical activity of very short duration, fueled by the energy sources within the contracting muscles and independent of the use of inhaled oxygen as an energy source.”
In plainer running terms, we are now out of the comfort zone and into the hurt locker at a pace we know we can’t sustain for very long.
When we get to above 80% of our maximum heart rate, we enter the anaerobic zone. Here, we stop using oxygen to power the muscles and without oxygen we can’t burn much fat. This means, as stated in the above definition, we rely on the energy stored within our muscles. The primary energy source within muscles is glycogen and our glycogen reserves are used up much faster than our fat stores. At such high heart rates, glycogen is less efficient and yields less energy. Even fully topped up with pre-race pasta party carb-loading and good breakfast, our glycogen stores will only power us for less than two hours. If you’re running a marathon, that’s only enough if you plan on breaking the world record.
When you push yourself into the anaerobic zone then eventually you’ll run out of glycogen. This will not be pretty. Running out of glycogen is what we all know and dread as “hitting the wall” or “bonking.” Entering an anaerobic state is also the point where lactic acid really starts to build up in the muscles. This biological mechanism stops you pushing your muscles beyond their limits by slowing you down. It’s a clever evolutionary trick, but it’s not going to help you get that new PR you were hoping for.
The key outtake here for long distance runners is that we want our bodies performing in the aerobic zone for as long as possible on race day. Which means we need to train our bodies in the aerobic zone so we can go faster by burning fat without gobbling glycogen. You can probably see where this is going…”