After reading our last post, you may be wondering why it is that sitting for long periods of time can put you at risk for heart disease. Enter: Dr. Sara Mahoney, Exercise Physiologist! Ta daa! There are actually a couple of interesting reasons why sitting for long periods is bad for your health, and I think once you understand, you’ll be more motivated to move around.
1. Lipoprotein Lipase (LPL). This is an enzyme that helps you break down fats. Remember a few posts ago, I taught you how the body can either use fats or carbohydrates for energy? Well, fats give you a lot more bang for your buck, but most of them are stored away in your adipose tissue (fat stored under your skin). In order to use them for energy, you have to break them down from their triglyceride form into a free fatty acid, and in order to do that you need LPL. What’s crazy about LPL it’s really only released during muscle contraction. So, if you spend your entire day sitting down, you really aren’t contracting very many of your muscles, and therefore your LPL levels plummet. Just going from a sitting to a standing position significantly increases the number of muscles you are contracting and increases the amount of fat you burn for energy.
2. VO2 (volume of oxygen). VO2 is a measure of how hard the body is working by measuring how much oxygen you take in with each breath and use throughout the body. You can also use VO2 to calculate the number of calories per minute you burn. When you are sitting down your VO2 is about 2-3 ml/kg/min, but when you just stand up, your VO2 doubles! That means your body is working twice as hard when you are standing up versus when you stay seated.
3. Total calorie burn. Studies have shown that people who spend the day walking around burn up to three times the number of calories as those who spend the day at a desk. Sitting is the most sedendary thing you can do. Even independent of evening workouts, this increased total calorie burn from an active day often leads to smaller waist circumferences and lower total body weight, reducing your risk for cardiovascular disease.
So, in summary, just by walking around during the day, you are helping your body burn more fat, burn more calories and reduce your waistline. All of these factors can reduce your risk for heart disease. For tips on how to get moving during the day if you have a desk job, check the previous post!
-Sara
LosingTogether 