The Other Four Letter Words

Why Hiit Works

CARB, EPOC and HIIT! I’m fairly confident that fad diets will never go away, at least until the current political structures that subsidize unhealthy lifestyles, like the farm bill and oil wars, are dismantled. Carbohydrates fuel our bodies. But too many carbohydrates can make us sick. And our current system likes to feed us a lot of carbohydrates.

Eat at Least 60 Grams of Carbs a Day

I have food sensitivities so I avoid most breads and baked goods.  I don’t deny myself the carbohydrate rich foods I can eat, like tortilla chips. In general I don’t count calories but will sometimes count grams, to make sure I’m getting enough of them.

If you are going to eat carbs try to make sure they’re worth eating. That means whatever is about to go in your mouth should be packed with nutrients and fiber, like whole grains or sweet potatoes. Fiber helps slow down the release of glucose into our bloodstream so our bodies can release an appropriate amount of insulin to transport the glucose. Too much unused insulin can lead to insulin insensitivity or diabetes. Our bodies have evolved over millennia to store carbohydrates as glucose to use fuel our daily lives.

Carbs Fuel Our Main Energy Systems

Our muscles have 3 energy systems that come into play at various stages in our workout. They all essentially run on adenosine triphosphate, ATP. A small amount of ATP is stored within our muscles for short burst of energy like catching a falling baby or throwing a spear at a predator. After a few seconds your glycolytic system kicks in and starts cobbling together ATP from stored glucose. This system is also short lived while a build up of hydrogen ions, a byproduct of glycolis, starts to inhibit muscle contraction.

Finally the oxidative system comes into play. Our aerobic system is constantly humming in the background of our daily life, fueling our muscles for basic functioning, like walking and digesting. When we put extra stress on our muscles, especially during exercise, our oxidative system goes into overdrive. After just over a minute of intense movement or lifting, our aerobic system redirects its efforts to focus on delivering oxygen to our muscles and will continue working well after a workout. This is known as the excess post-exercise oxygen consumption, EPOC. Basically our muscles are still “burning” calories for hours after we’ve completed a workout because they are repairing themselves.

This EPOC effect has contributed the success of high intensity integral training, HIIT. Doing intense activities for short periods of times (20-90 seconds) with short recovery times (10-60 seconds) repeatedly helps our bodies utilize all our metabolic energy systems and keeps us metabolically flexible.

Our bodies most easily use glucose from carbohydrates to fuel our muscles so don’t feel bad about eating carbs, feel good about putting them to use!

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