Ever wonder why when you take 1 or 2 weeks off of exercising, why it is so hard on your cardiovascular system when you do come back to exercising? Do you really fall out of shape that fast? Unfortunately, the answer is YES:
Cardiovascular deconditioning is exactly what it sounds like; it is the body’s cardiovascular conditioning declining. After 2 weeks of not exercising, on average, your VO2 Max (your body’s ability to utilize oxygen for energy, which is the best indicator of your cardiovascular fitness) decreases by up to 20%! This is because your body loses mitochondria (the things in your cells that convert oxygen to energy). If you are a conditioned individual this happens at a slower rate vs. an individual that is just beginning a workout plan. One study actually showed that you lose as much mitochondrial content in two weeks as it would take you in 6 weeks of training.
Now do not take all of this information the wrong way, it is extremely important to take days off to allow your body to recover, build, and prevent overuse injuries. The message is to try and avoid taking more then 1-2 weeks off of all exercising. Things do sometimes pop up in life that are unexpected, and if you are forced to take time off, please remember do not ever let yourself get discouraged. Fitness is a life long journey, not a destination, and being patient and smart will allow you to enjoy all of the benefits physically and mentally that exercise and fitness can provide.